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Zambelli V, Sigurtà A, Rizzi L, Zucca L, Delvecchio P, Bresciani E, Torsello A, Bellani G. Angiotensin-(1-7) exerts a protective action in a rat model of ventilator-induced diaphragmatic dysfunction. Intensive Care Med Exp 2019; 7:8. [PMID: 30659381 PMCID: PMC6338614 DOI: 10.1186/s40635-018-0218-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 12/25/2018] [Indexed: 12/11/2022] Open
Abstract
Background Ventilator-induced diaphragmatic dysfunction (VIDD) is a common event during mechanical ventilation (MV) leading to rapid muscular atrophy and contractile dysfunction. Recent data show that renin-angiotensin system is involved in diaphragmatic skeletal muscle atrophy after MV. In particular, angiotensin-II can induce marked diaphragm muscle wasting, whereas angiotensin-(1–7) (Ang-(1–7)) could counteract this activity. This study was designed to evaluate the effects of the treatment with Ang-(1–7) in a rat model of VIDD with neuromuscular blocking agent infusion. Moreover, we studied whether the administration of A-779, an antagonist of Ang-(1–7) receptor (Mas), alone or in combination with PD123319, an antagonist of AT2 receptor, could antagonize the effects of Ang-(1–7). Methods Sprague-Dawley rats underwent prolonged MV (8 h), while receiving an iv infusion of sterile saline 0.9% (vehicle) or Ang-(1–7) or Ang-(1–7) + A-779 or Ang-(1–7) + A-779 + PD123319. Diaphragms were collected for ex vivo contractility measurement (with electric stimulation), histological analysis, quantitative real-time PCR, and Western blot analysis. Results MV resulted in a significant reduction of diaphragmatic contractility in all groups of treatment. Ang-(1–7)-treated rats showed higher muscular fibers cross-sectional area and lower atrogin-1 and myogenin mRNA levels, compared to vehicle treatment. Treatment with the antagonists of Mas and Ang-II receptor 2 (AT2R) caused a significant reduction of muscular contractility and an increase of atrogin-1 and MuRF-1 mRNA levels, not affecting the cross-sectional fiber area and myogenin mRNA levels. Conclusions Systemic Ang-(1–7) administration during MV exerts a protective role on the muscular fibers of the diaphragm preserving muscular fibers anatomy, and reducing atrophy. The involvement of Mas and AT2R in the mechanism of action of Ang-(1–7) still remains controversial.
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Affiliation(s)
- Vanessa Zambelli
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Anna Sigurtà
- Anesthesia and Critical Care, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Laura Rizzi
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Letizia Zucca
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Paolo Delvecchio
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Elena Bresciani
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Antonio Torsello
- Department of Medicine, University of Milano-Bicocca, Monza, Italy
| | - Giacomo Bellani
- Department of Medicine, University of Milano-Bicocca, Monza, Italy.
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52
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Evans D, Shure D, Clark L, Criner GJ, Dres M, de Abreu MG, Laghi F, McDonagh D, Petrof B, Nelson T, Similowski T. Temporary transvenous diaphragm pacing vs. standard of care for weaning from mechanical ventilation: study protocol for a randomized trial. Trials 2019; 20:60. [PMID: 30654837 PMCID: PMC6337771 DOI: 10.1186/s13063-018-3171-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/31/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Mechanical ventilation (MV) is a life-saving technology that restores or assists breathing. Like any treatment, MV has side effects. In some patients it can cause diaphragmatic atrophy, injury, and dysfunction (ventilator-induced diaphragmatic dysfunction, VIDD). Accumulating evidence suggests that VIDD makes weaning from MV difficult, which involves increased morbidity and mortality. METHODS AND ANALYSIS This paper describes the protocol of a randomized, controlled, open-label, multicenter trial that is designed to investigate the safety and effectiveness of a novel therapy, temporary transvenous diaphragm pacing (TTVDP), to improve weaning from MV in up to 88 mechanically ventilated adult patients who have failed at least two spontaneous breathing trials over at least 7 days. Patients will be randomized (1:1) to TTVDP (treatment) or standard of care (control) groups. The primary efficacy endpoint is time to successful extubation with no reintubation within 48 h. Secondary endpoints include maximal inspiratory pressure and ultrasound-measured changes in diaphragm thickness and diaphragm thickening fraction over time. In addition, observational data will be collected and analyzed, including 30-day mortality and time to discharge from the intensive care unit and from the hospital. The hypothesis to be tested postulates that more TTVDP patients than control patients will be successfully weaned from MV within the 30 days following randomization. DISCUSSION This study is the first large-scale clinical trial of a novel technology (TTVDP) aimed at accelerating difficult weaning from MV. The technology tested provides the first therapy directed specifically at VIDD, an important cause of delayed weaning from MV. Its results will help delineate the place of this therapeutic approach in clinical practice and help design future studies aimed at defining the indications and benefits of TTVDP. TRIAL REGISTRATION ClinicalTrials.gov, NCT03096639 . Registered on 30 March 2017.
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Affiliation(s)
- Douglas Evans
- Lungpacer Medical Incorporated, Burnaby, BC, Canada.,Lungpacer Medical, 260 Sierra Drive, Exton, PA, 19335, USA
| | | | - Linda Clark
- Lungpacer Medical Incorporated, Burnaby, BC, Canada
| | - Gerard J Criner
- Department of Thoracic Medicine and Surgery, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Martin Dres
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique and AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale du Département R3S, Paris, France
| | - Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Franco Laghi
- Division of Pulmonary and Critical Care Medicine, Hines Veterans Affairs Hospital Hines, Loyola University, Maywood, IL, USA
| | - David McDonagh
- Departments of Anesthesiology and Pain Management, Neurological surgery, Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Basil Petrof
- Meakins-Christie Laboratories, and Translational Research in Respiratory Diseases Program, McGill University Health Centre and Research Institute, Montreal, QC, Canada
| | | | - Thomas Similowski
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique and AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale du Département R3S, Paris, France.
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53
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Inspiratory Muscle Training in Patients with Prolonged Mechanical Ventilation: Narrative Review. Cardiopulm Phys Ther J 2019; 30:44-50. [PMID: 31105474 DOI: 10.1097/cpt.0000000000000092] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Patients with impending respiratory failure often require mechanical ventilation to optimize gas exchange. Although this form of assisted ventilation is required for survival, its persistent use results in diaphragm weakness and muscle fiber atrophy. There is strong evidence that mechanical ventilation alters the structure and function of the diaphragm, resulting in prolonged dependence on assisted ventilation and long-term consequences such as a delayed functional recovery, reduced quality of life and increased risk of mortality. This review summarizes the mechanisms underlying diaphragm dysfunction due to prolonged mechanical ventilation, highlights the role of inspiratory muscle exercise as a strategy to counter diaphragm weakness, and identifies the parameters of an evidence-supported exercise prescription for difficult to wean patients.
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54
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Liu YY, Li LF. Ventilator-induced diaphragm dysfunction in critical illness. Exp Biol Med (Maywood) 2018; 243:1329-1337. [PMID: 30453774 DOI: 10.1177/1535370218811950] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
IMPACT STATEMENT Mechanical ventilation (MV) is life-saving for patients with acute respiratory failure but also causes difficult liberation of patients from ventilator due to rapid decrease of diaphragm muscle endurance and strength, which is termed ventilator-induced diaphragmatic damage (VIDD). Numerous studies have revealed that VIDD could increase extubation failure, ICU stay, ICU mortality, and healthcare expenditures. However, the mechanisms of VIDD, potentially involving a multistep process including muscle atrophy, oxidative loads, structural damage, and muscle fiber remodeling, are not fully elucidated. Further research is necessary to unravel mechanistic framework for understanding the molecular mechanisms underlying VIDD, especially mitochondrial dysfunction and increased mitochondrial oxidative stress, and develop better MV strategies, rehabilitative programs, and pharmacologic agents to translate this knowledge into clinical benefits.
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Affiliation(s)
- Yung-Yang Liu
- 1 Chest Department, Taipei Veterans General Hospital, Taipei 112, Taiwan.,2 Institutes of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Li-Fu Li
- 3 Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan 333, Taiwan.,4 Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
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55
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Endurance exercise protects skeletal muscle against both doxorubicin-induced and inactivity-induced muscle wasting. Pflugers Arch 2018; 471:441-453. [PMID: 30426248 DOI: 10.1007/s00424-018-2227-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/09/2018] [Accepted: 10/18/2018] [Indexed: 12/20/2022]
Abstract
Repeated bouts of endurance exercise promotes numerous biochemical adaptations in skeletal muscle fibers resulting in a muscle phenotype that is protected against a variety of homeostatic challenges; these exercise-induced changes in muscle phenotype are often referred to as "exercise preconditioning." Importantly, exercise preconditioning provides protection against several threats to skeletal muscle health including cancer chemotherapy (e.g., doxorubicin) and prolonged muscle inactivity. This review summarizes our current understanding of the mechanisms responsible for exercise-induced protection of skeletal muscle fibers against both doxorubicin-induced muscle wasting and a unique form of inactivity-induced muscle atrophy (i.e., ventilator-induced diaphragm atrophy). Specifically, the first section of this article will highlight the potential mechanisms responsible for exercise-induced protection of skeletal muscle fibers against doxorubicin-induced fiber atrophy. The second segment will discuss the biochemical changes that are responsible for endurance exercise-mediated protection of diaphragm muscle against ventilator-induced diaphragm wasting. In each section, we highlight gaps in our knowledge in hopes of stimulating future research in this evolving field of investigation.
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56
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Powers SK, Morton AB, Hyatt H, Hinkley MJ. The Renin-Angiotensin System and Skeletal Muscle. Exerc Sport Sci Rev 2018; 46:205-214. [PMID: 30001274 DOI: 10.1249/jes.0000000000000158] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The renin-angiotensin system (RAS) plays a key role in the control of blood pressure and fluid homeostasis. Emerging evidence also reveals that hyperactivity of the RAS contributes to skeletal muscle wasting. This review discusses the key role that the RAS plays in skeletal muscle wasting due to congestive heart failure, chronic kidney disease, and ventilator-induced diaphragmatic wasting.
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Affiliation(s)
- Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL
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57
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Increased SOD2 in the diaphragm contributes to exercise-induced protection against ventilator-induced diaphragm dysfunction. Redox Biol 2018; 20:402-413. [PMID: 30414534 PMCID: PMC6226598 DOI: 10.1016/j.redox.2018.10.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/04/2018] [Accepted: 10/08/2018] [Indexed: 01/22/2023] Open
Abstract
Mechanical ventilation (MV) is a life-saving intervention for many critically ill patients. Unfortunately, prolonged MV results in rapid diaphragmatic atrophy and contractile dysfunction, collectively termed ventilator-induced diaphragm dysfunction (VIDD). Recent evidence reveals that endurance exercise training, performed prior to MV, protects the diaphragm against VIDD. While the mechanism(s) responsible for this exercise-induced protection against VIDD remain unknown, increased diaphragm antioxidant expression may be required. To investigate the role that increased antioxidants play in this protection, we tested the hypothesis that elevated levels of the mitochondrial antioxidant enzyme superoxide dismutase 2 (SOD2) is required to achieve exercise-induced protection against VIDD. Cause and effect was investigated in two ways. First, we prevented the exercise-induced increase in diaphragmatic SOD2 via delivery of an antisense oligonucleotide targeted against SOD2 post-exercise. Second, using transgene overexpression of SOD2, we determined the effects of increased SOD2 in the diaphragm independent of exercise training. Results from these experiments revealed that prevention of the exercise-induced increases in diaphragmatic SOD2 results in a loss of exercise-mediated protection against MV-induced diaphragm atrophy and a partial loss of protection against MV-induced diaphragmatic contractile dysfunction. In contrast, transgenic overexpression of SOD2 in the diaphragm, independent of exercise, did not protect against MV-induced diaphragmatic atrophy and provided only partial protection against MV-induced diaphragmatic contractile dysfunction. Collectively, these results demonstrate that increased diaphragmatic levels of SOD2 are essential to achieve the full benefit of exercise-induced protection against VIDD. Prolonged mechanical ventilation results in diaphragmatic weakness which is labeled as ventilator-induced diaphragm dysfunction (VIDD). Endurance exercise training performed prior to mechanical ventilation protects the diaphragm against VIDD. Preventing exercise-induced increases of superoxide dismutase 2 (SOD2) in the diaphragm partially abolishes exercise protection against VIDD. Transgenic overexpression of SOD2 in the diaphragm provides only partial protection against VIDD. We conclude that increases in SOD2 abundance in the diaphragm contributes to the exercise-induced protection against VIDD.
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58
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Dos Santos FV, Cipriano G, Vieira L, Güntzel Chiappa AM, Cipriano GBF, Vieira P, Zago JG, Castilhos M, da Silva ML, Chiappa GR. Neuromuscular electrical stimulation combined with exercise decreases duration of mechanical ventilation in ICU patients: A randomized controlled trial. Physiother Theory Pract 2018; 36:580-588. [PMID: 30321084 DOI: 10.1080/09593985.2018.1490363] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Early mobilization can be employed to minimize the duration of intensive care. However, a protocol combining neuromuscular electrical stimulation (NMES) with early mobilization has not yet been tested in ICU patients. Our aim was to assess the efficacy of NMES, exercise (EX), and combined therapy (NMES + EX) on duration of mechanical ventilation (MV) in critically ill patients. METHODS The participants in this randomized double-blind trial were prospectively recruited within 24 hours following admission to the intensive care unit of a tertiary hospital. Eligible patients had 18 years of age or older; MV for less than 72 hours; and no known neuromuscular disease. Computer-generated permuted block randomization was used to assign patients to NMES, EX, NMES + EX, or standard care (control group). The main endpoint was duration of MV. Clinical characteristics were also evaluated and intention to treat analysis was employed. RESULTS One hundred forty-four patients were assessed for eligibility to participate in the trial, 51 of whom were enrolled and randomly allocated into four groups: 11 patients in the NMES group, 13 in the EX group, 12 in the NMES + EX group, and 15 in the control group (CG). Duration of MV (days) was significantly shorter in the combined therapy (5.7 ± 1.1) and NMEN (9.0 ± 7.0) groups in comparison to CG (14.8 ± 5.4). CONCLUSIONS NMES + EX consisting of NMES and active EXs was well tolerated and resulted in shorter duration of MV in comparison to standard care or isolated therapy (NMES or EX alone).
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Affiliation(s)
- Francisco Valdez Dos Santos
- Physical Therapy Department, University of Brasilia , Brasilia, Brazil.,Cancer Institute of São Paulo, São Paulo , Brazil
| | - Gerson Cipriano
- Physical Therapy Department, University of Brasilia , Brasilia, Brazil
| | - Luciana Vieira
- Physical Therapy Department, University of Brasilia , Brasilia, Brazil.,Clinical Research Center, Hospital de Base do Distrito Federal , Brasilia, Brazil
| | | | | | - Paulo Vieira
- Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
| | - Julio G Zago
- Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
| | | | | | - Gaspar R Chiappa
- Physical Therapy Department, University of Brasilia , Brasilia, Brazil.,Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil.,Centro Universitário do Planalto Central Professor Apparecido dos Santos , Brasilia, Brazil
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59
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de Vries H, Jonkman A, Shi ZH, Spoelstra-de Man A, Heunks L. Assessing breathing effort in mechanical ventilation: physiology and clinical implications. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:387. [PMID: 30460261 DOI: 10.21037/atm.2018.05.53] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recent studies have shown both beneficial and detrimental effects of patient breathing effort in mechanical ventilation. Quantification of breathing effort may allow the clinician to titrate ventilator support to physiological levels of respiratory muscle activity. In this review we will describe the physiological background and methodological issues of the most frequently used methods to quantify breathing effort, including esophageal pressure measurement, the work of breathing, the pressure-time-product, electromyography and ultrasound. We will also discuss the level of breathing effort that may be considered optimal during mechanical ventilation at different stages of critical illness.
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Affiliation(s)
- Heder de Vries
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Annemijn Jonkman
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Zhong-Hua Shi
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands.,Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Angélique Spoelstra-de Man
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Leo Heunks
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
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60
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Attenuation of ventilation-induced diaphragm dysfunction through toll-like receptor 4 and nuclear factor-κB in a murine endotoxemia model. J Transl Med 2018; 98:1170-1183. [PMID: 29925937 DOI: 10.1038/s41374-018-0081-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 01/30/2023] Open
Abstract
Mechanical ventilation (MV) is often used to maintain life in patients with sepsis and sepsis-related acute lung injury. However, controlled MV may cause diaphragm weakness due to muscle injury and atrophy, an effect termed ventilator-induced diaphragm dysfunction (VIDD). Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) signaling pathways may elicit sepsis-related acute inflammatory responses and muscle protein degradation and mediate the pathogenic mechanisms of VIDD. However, the mechanisms regulating the interactions between VIDD and endotoxemia are unclear. We hypothesized that mechanical stretch with or without endotoxin treatment would augment diaphragmatic structural damage, the production of free radicals, muscle proteolysis, mitochondrial dysfunction, and autophagy of the diaphragm via the TLR4/NF-κB pathway. Male C57BL/6 mice, either wild-type or TLR4-deficient, aged between 6 and 8 weeks were exposed to MV (6 mL/kg or 10 mL/kg) with or without endotoxemia for 8 h. Nonventilated mice were used as controls. MV with endotoxemia aggravated VIDD, as demonstrated by the increases in the expression levels of TLR4, caspase-3, atrogin-1, muscle ring finger-1, and microtubule-associated protein light chain 3-II. In addition, increased NF-κB phosphorylation and oxidative loads, disorganized myofibrils, disrupted mitochondria, autophagy, and myonuclear apoptosis were also observed. Furthermore, MV with endotoxemia reduced P62 levels and diaphragm muscle fiber size (P < 0.05). Endotoxin-exacerbated VIDD was attenuated by pharmacologic inhibition with a NF-κB inhibitor or in TLR4-deficient mice (P < 0.05). Our data indicate that endotoxin-augmented MV-induced diaphragmatic injury occurs through the activation of the TLR4/NF-κB signaling pathway.
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61
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Diaphragm Weakness in the Critically Ill: Basic Mechanisms Reveal Therapeutic Opportunities. Chest 2018; 154:1395-1403. [PMID: 30144420 DOI: 10.1016/j.chest.2018.08.1028] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/23/2018] [Accepted: 08/01/2018] [Indexed: 12/11/2022] Open
Abstract
The diaphragm is the primary muscle of inspiration. Its capacity to respond to the load imposed by pulmonary disease is a major determining factor both in the onset of ventilatory failure and in the ability to successfully separate patients from ventilator support. It has recently been established that a very large proportion of critically ill patients exhibit major weakness of the diaphragm, which is associated with poor clinical outcomes. The two greatest risk factors for the development of diaphragm weakness in critical illness are the use of mechanical ventilation and the presence of sepsis. Loss of force production by the diaphragm under these conditions is caused by a combination of defective contractility and reduced diaphragm muscle mass. Importantly, many of the same molecular mechanisms are implicated in the diaphragm dysfunction associated with both mechanical ventilation and sepsis. This review outlines the primary cellular mechanisms identified thus far at the nexus of diaphragm dysfunction associated with mechanical ventilation and/or sepsis, and explores the potential for treatment or prevention of diaphragm weakness in critically ill patients through therapeutic manipulation of these final common pathway targets.
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62
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Song Y, Dahl M, Leavitt W, Alvord J, Bradford CY, Albertine KH, Pillow JJ. Vitamin A Protects the Preterm Lamb Diaphragm Against Adverse Effects of Mechanical Ventilation. Front Physiol 2018; 9:1119. [PMID: 30150942 PMCID: PMC6099107 DOI: 10.3389/fphys.2018.01119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/25/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Preterm infants are deficient in vitamin A, which is essential for growth and development of the diaphragm. Preterm infants often require mechanical ventilation (MV) for respiratory distress. In adults, MV is associated with the development of ventilation-induced diaphragm dysfunction and difficulty weaning from the ventilator. We assessed the impact of MV on the preterm diaphragm and the protective effect of vitamin A during MV. Methods: Preterm lambs delivered operatively at ∼131 days gestation (full gestation: 150 days) received respiratory support by synchronized intermittent mandatory ventilation for 3 days. Lambs in the treated group received daily (24 h) enteral doses of 2500 IU/kg/day vitamin A combined with 250 IU/kg/day retinoic acid (VARA) during MV, while MV control lambs received saline. Unventilated fetal reference lambs were euthanized at birth, without being allowed to breathe. The fetal diaphragm was collected to quantify mRNA levels of myosin heavy chain (MHC) isoforms, atrophy genes, antioxidant genes, and pro-inflammatory genes; to determine ubiquitin proteasome pathway activity; to measure the abundance of protein carbonyl, and to investigate metabolic signaling. Results: Postnatal MV significantly decreased expression level of the neonatal MHC gene but increased expression level of MHC IIx mRNA level (p < 0.05). Proteasome activity increased after 3 days MV, accompanied by increased MuRF1 mRNA level and accumulated protein carbonyl abundance. VARA supplementation decreased proteasome activity and FOXO1 signaling, down-regulated MuRF1 expression, and reduced reactive oxidant production. Conclusion: These findings suggest that 3 days of MV results in abnormal myofibrillar composition, activation of the proteolytic pathway, and oxidative injury of diaphragms in mechanically ventilated preterm lambs. Daily enteral VARA protects the preterm diaphragm from these adverse effects.
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Affiliation(s)
- Yong Song
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Centre for Neonatal Research and Education, Division of Paediatrics and Child Health, Medical School, The University of Western Australia, Crawley, WA, Australia.,School of Public Health, Curtin University, Bentley, WA, Australia.,Centre for Genetic Origins of Health and Disease, The University of Western Australia, Curtin University, Crawley, WA, Australia
| | - MarJanna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Wendy Leavitt
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Jeremy Alvord
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Calan Y Bradford
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah, Salt Lake City, UT, United States
| | - J Jane Pillow
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Centre for Neonatal Research and Education, Division of Paediatrics and Child Health, Medical School, The University of Western Australia, Crawley, WA, Australia
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63
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Sekiguchi H, Tamaki Y, Kondo Y, Nakamura H, Hanashiro K, Yonemoto K, Moritani T, Kukita I. Surface electromyographic evaluation of the neuromuscular activation of the inspiratory muscles during progressively increased inspiratory flow under inspiratory-resistive loading. Physiol Int 2018; 105:86-99. [PMID: 29602291 DOI: 10.1556/2060.105.2018.1.3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study aimed to evaluate neuromuscular activation in the scalene and sternocleidomastoid muscles using surface electromyography (EMG) during progressively increased inspiratory flow, produced by increasing the respiratory rate under inspiratory-resistive loading using a mask ventilator. Moreover, we attempted to identify the EMG inflection point (EMGIP) on the graph, at which the root mean square (RMS) of the EMG signal values of the inspiratory muscles against the inspiratory flow velocity acceleration abruptly increases, similarly to the EMG anaerobic threshold (EMGAT) reported during incremental-resistive loading in other skeletal muscles. We measured neuromuscular activation of healthy male subjects and found that the inspiratory flow velocity increased by approximately 1.6-fold. We successfully observed an increase in RMS that corresponded to inspiratory flow acceleration with ρ ≥ 0.7 (Spearman's rank correlation) in 17 of 27 subjects who completed the experimental protocol. To identify EMGIP, we analyzed the fitting to either a straight or non-straight line related to the increasing inspiratory flow and RMS using piecewise linear spline functions. As a result, EMGIP was identified in the scalene and sternocleidomastoid muscles of 17 subjects. We believe that the identification of EMGIP in this study infers the existence of EMGAT in inspiratory muscles. Application of surface EMG, followed by identification of EMGIP, for evaluating the neuromuscular activation of respiratory muscles may be allowed to estimate the signs of the respiratory failure, including labored respiration, objectively and non-invasively accompanied using accessory muscles in clinical respiratory care.
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Affiliation(s)
- H Sekiguchi
- 1 Department of Intensive Care, Tomishiro Central Hospital , Okinawa, Japan.,2 Department of Emergency and Critical Care Medicine, Graduate School of Medicine, University of the Ryukyus , Okinawa, Japan
| | - Y Tamaki
- 2 Department of Emergency and Critical Care Medicine, Graduate School of Medicine, University of the Ryukyus , Okinawa, Japan
| | - Y Kondo
- 2 Department of Emergency and Critical Care Medicine, Graduate School of Medicine, University of the Ryukyus , Okinawa, Japan
| | - H Nakamura
- 3 Faculty of Biomedical Engineering, Department of Health-Promotion and Sports Science, Osaka Electro-Communication University , Osaka, Japan
| | - K Hanashiro
- 4 Department of Public Health and Hygiene, Graduate School of Medicine, University of the Ryukyus , Okinawa, Japan
| | - K Yonemoto
- 5 Faculty of Medicine, Advanced Medical Research Center, University of the Ryukyus , Okinawa, Japan
| | - T Moritani
- 6 Department of Applied Physiology, Institute for the Promotion of Common Education, Kyoto Sangyo University , Kyoto, Japan
| | - I Kukita
- 2 Department of Emergency and Critical Care Medicine, Graduate School of Medicine, University of the Ryukyus , Okinawa, Japan
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Chen JO, Liu JF, Liu YQ, Chen YM, Tu ML, Yu HR, Lin MC, Lin CC, Liu SF. Effectiveness of a perioperative pulmonary rehabilitation program following coronary artery bypass graft surgery in patients with and without COPD. Int J Chron Obstruct Pulmon Dis 2018; 13:1591-1597. [PMID: 29805258 PMCID: PMC5960241 DOI: 10.2147/copd.s157967] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Purpose It is unclear whether the effectiveness of pulmonary rehabilitation program (PRP) after cardiac surgery differs between patients with and without COPD. This study aimed to compare the effectiveness of PRP between patients with and without COPD undergoing coronary artery bypass graft (CABG) surgery. Patients and methods We retrospectively included patients who underwent CABG surgery and received 3-week PRP from January 2009 to December 2013. We excluded patients who underwent emergency surgery, had an unstable hemodynamic status, were ventilator dependent or did not complete the PRP. Demographics, muscle strength, degree of dyspnea, pulmonary function and postoperative complications were compared. Results Seventy-eight patients were enrolled (COPD group, n=40; non-COPD group, n=38). Maximal inspiratory pressure (MIP; −34.52 cmH2O vs −43.25 cmH2O, P<0.01; −34.67 cmH2O vs −48.18 cmH2O, P<0.01), maximal expiratory pressure (MEP; 32.15 cmH2O vs 46.05 cmH2O, P<0.01; 37.78 cmH2O vs 45.72 cmH2O, P<0.01) and respiratory rate (RR; 20.65 breath/minute vs 17.02 breath/minute, P<0.01; 20.65 breath/minute vs 17.34 breath/minute, P<0.01) in COPD and non-COPD groups, respectively, showed significant improvement, but were not significantly different between the two groups. Forced vital capacity (FVC; 0.85 L vs 1.25 L, P<0.01), forced expiratory volume in 1 second (FEV1; 0.75 L vs 1.08 L, P<0.01), peak expiratory flow (PEF; 0.99 L vs 1.79 L, P<0.01) and forced expiratory flow between 25% and 75% of vital capacity (FEF25–75; 0.68 L vs 1.15 L, P<0.01) showed significant improvement between postoperative Days 1 and 14 in the COPD group. FVC (1.11 L vs 1.36 L, P<0.05), FEV1 (96 L vs 1.09 L, P<0.05) and FEF25–75 (1.03 L vs 1.26 L, P<0.05) were significantly improved in the non-COPD group. However, only PEF (80.8% vs 10.1%, P<0.01) and FEF25–75 (67.6% vs 22.3%, P<0.05) were more significantly improved in the COPD group than in the non-COPD group. Conclusion PRP significantly improved respiratory muscle strength and lung function in patients with and without COPD who underwent CABG surgery. However, PRP is more effective in improving PEF and FEF25–75 in COPD patients.
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Affiliation(s)
- Jui-O Chen
- Department of Nursing, Tajen University, Pingtung, Taiwan.,College of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jui-Fang Liu
- Department of Nursing, Tajen University, Pingtung, Taiwan.,Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital-Kaohsiung Medical Center and Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Respiratory Care, Chang Gung University of Science and Technology, Taoyuan, Taiwan.,Department of Education, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Yu-Qi Liu
- Department of Intensive Care unit, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Yu-Mu Chen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Mei-Lien Tu
- Respiratory Care, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Hong-Ren Yu
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Meng-Chih Lin
- Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital-Kaohsiung Medical Center and Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chiu-Chu Lin
- College of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shih-Feng Liu
- Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital-Kaohsiung Medical Center and Chang Gung University College of Medicine, Kaohsiung, Taiwan.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
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Diaphragm abnormalities in heart failure and aging: mechanisms and integration of cardiovascular and respiratory pathophysiology. Heart Fail Rev 2018; 22:191-207. [PMID: 27000754 DOI: 10.1007/s10741-016-9549-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inspiratory function is essential for alveolar ventilation and expulsive behaviors that promote airway clearance (e.g., coughing and sneezing). Current evidence demonstrates that inspiratory dysfunction occurs during healthy aging and is accentuated by chronic heart failure (CHF). This inspiratory dysfunction contributes to key aspects of CHF and aging cardiovascular and pulmonary pathophysiology including: (1) impaired airway clearance and predisposition to pneumonia; (2) inability to sustain ventilation during physical activity; (3) shallow breathing pattern that limits alveolar ventilation and gas exchange; and (4) sympathetic activation that causes cardiac arrhythmias and tissue vasoconstriction. The diaphragm is the primary inspiratory muscle; hence, its neuromuscular integrity is a main determinant of the adequacy of inspiratory function. Mechanistic work within animal and cellular models has revealed specific factors that may be responsible for diaphragm neuromuscular abnormalities in CHF and aging. These include phrenic nerve and neuromuscular junction alterations as well as intrinsic myocyte abnormalities, such as changes in the quantity and quality of contractile proteins, accelerated fiber atrophy, and shifts in fiber type distribution. CHF, aging, or CHF in the presence of aging disturbs the dynamics of circulating factors (e.g., cytokines and angiotensin II) and cell signaling involving sphingolipids, reactive oxygen species, and proteolytic pathways, thus leading to the previously listed abnormalities. Exercise-based rehabilitation combined with pharmacological therapies targeting the pathways reviewed herein hold promise to treat diaphragm abnormalities and inspiratory muscle dysfunction in CHF and aging.
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66
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Diaphragm Muscle Weakness Following Acute Sustained Hypoxic Stress in the Mouse Is Prevented by Pretreatment with N-Acetyl Cysteine. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4805493. [PMID: 29670681 PMCID: PMC5836441 DOI: 10.1155/2018/4805493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/29/2017] [Accepted: 12/12/2017] [Indexed: 12/18/2022]
Abstract
Oxygen deficit (hypoxia) is a major feature of cardiorespiratory diseases characterized by diaphragm dysfunction, yet the putative role of hypoxic stress as a driver of diaphragm dysfunction is understudied. We explored the cellular and functional consequences of sustained hypoxic stress in a mouse model. Adult male mice were exposed to 8 hours of normoxia, or hypoxia (FiO2 = 0.10) with or without antioxidant pretreatment (N-acetyl cysteine, 200 mg/kg i.p.). Ventilation and metabolism were measured. Diaphragm muscle contractile function, myofibre size and distribution, gene expression, protein signalling cascades, and oxidative stress (TBARS) were determined. Hypoxia caused pronounced diaphragm muscle weakness, unrelated to increased respiratory muscle work. Hypoxia increased diaphragm HIF-1α protein content and activated MAPK, mTOR, Akt, and FoxO3a signalling pathways, largely favouring protein synthesis. Hypoxia increased diaphragm lipid peroxidation, indicative of oxidative stress. FoxO3 and MuRF-1 gene expression were increased. Diaphragm 20S proteasome activity and muscle fibre size and distribution were unaffected by acute hypoxia. Pretreatment with N-acetyl cysteine substantially enhanced cell survival signalling, prevented hypoxia-induced diaphragm oxidative stress, and prevented hypoxia-induced diaphragm dysfunction. Hypoxia is a potent driver of diaphragm weakness, causing myofibre dysfunction without attendant atrophy. N-acetyl cysteine protects the hypoxic diaphragm and may have application as a potential adjunctive therapy.
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67
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Smuder AJ, Sollanek KJ, Nelson WB, Min K, Talbert EE, Kavazis AN, Hudson MB, Sandri M, Szeto HH, Powers SK. Crosstalk between autophagy and oxidative stress regulates proteolysis in the diaphragm during mechanical ventilation. Free Radic Biol Med 2018; 115:179-190. [PMID: 29197632 PMCID: PMC5767544 DOI: 10.1016/j.freeradbiomed.2017.11.025] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 12/25/2022]
Abstract
Mechanical ventilation (MV) results in the rapid development of ventilator-induced diaphragm dysfunction (VIDD). While the mechanisms responsible for VIDD are not fully understood, recent data reveal that prolonged MV activates autophagy in the diaphragm, which may occur as a result of increased cellular reactive oxygen species (ROS) production. Therefore, we tested the hypothesis that (1) accelerated autophagy is a key contributor to VIDD; and that (2) oxidative stress is required to increase the expression of autophagy genes in the diaphragm. Our findings reveal that targeted inhibition of autophagy in the rat diaphragm prevented MV-induced muscle atrophy and contractile dysfunction. Attenuation of VIDD in these animals occurred as a result of increased diaphragm concentration of the antioxidant catalase and reduced mitochondrial ROS emission, which corresponded to reductions in the activity of calpain and caspase-3. To determine if increased ROS production is required for the upregulation of autophagy biomarkers in the diaphragm, rats that were administered the mitochondrial-targeted peptide SS-31 during MV. Results from this study demonstrated that mitochondrial ROS production in the diaphragm during MV is required for the increased expression of key autophagy genes (i.e. LC3, Atg7, Atg12, Beclin1 and p62), as well as for increased activity of cathepsin L. Together, these data reveal that autophagy is required for VIDD, and that autophagy inhibition reduces MV-induced diaphragm ROS production and prevents a positive feedback loop whereby increased autophagy is stimulated by oxidative stress, resulting in further increases in ROS and autophagy.
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Affiliation(s)
- Ashley J Smuder
- Department of Exercise Science, University of South Carolina, Room 227, 921 Assembly St, Columbia, SC 29208, United States.
| | - Kurt J Sollanek
- Department of Kinesiology, Sonoma State University, Rohnert Park, CA 94928, United States
| | - W Bradley Nelson
- Department of Natural Sciences, Ohio Dominican University, Columbus, OH 43219, United States
| | - Kisuk Min
- Department of Pharmacology, Yale University, New Haven, CT 06520, United States
| | - Erin E Talbert
- Department of Molecular Virology, Immunology and Medical Genetics, Ohio State University, Columbus, OH 43210, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, AL 36849, United States
| | - Matthew B Hudson
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19716, United States
| | - Marco Sandri
- Department of Biomedical Science, University of Padova, Padova, Italy
| | - Hazel H Szeto
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10021, United States
| | - Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, United States
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Acceleration sensors in abdominal wall position as a non-invasive approach to detect early breathing alterations induced by intolerance of increased airway resistance. J Cardiothorac Surg 2017; 12:96. [PMID: 29126451 PMCID: PMC5681836 DOI: 10.1186/s13019-017-0658-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 11/01/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early detection of respiratory overload is crucial to mechanically ventilated patients, especially during phases of spontaneous breathing. Although a diversity of methods and indices has been established, there is no highly specific approach to predict respiratory failure. This study aimed to evaluate acceleration sensors in abdominal and thoracic wall positions to detect alterations in breathing excursions in a setting of gradual increasing airway resistance. METHODS Twenty-nine healthy volunteers were committed to a standardized protocol of a two-minutes step-down spontaneous breathing on a 5 mm, 4 mm and then 3 mm orally placed endotracheal tube. Accelerator sensors in thoracic and abdominal wall position monitored breathing excursions. 15 participants passed the breathing protocol ("completed" group), 14 individuals cancelled the protocol due to subjective intolerance to the increasing airway resistance ("abandoned" group). RESULTS Gradual increased respiratory workload led to a significant decrease of acceleration in abdominal wall position in the "abandoned" group compared to the "completed" group (p < 0.001), while these gradual accelerating changes were not observed in thoracic wall position (p = 0.484). Thoracic acceleration sensors did not detect any time- and group-specific changes (p = 0.746). CONCLUSIONS The abdominal wall position of the acceleration sensors may be a non-invasive, economical and practical approach to detect early breathing alterations prior to respiratory failure. TRIAL REGISTRATION EK 309-15; by the Ethics Committee of the Faculty of Medicine, RWTH Aachen, Aachen, Germany. Retrospectively registered 28th of December 2015.
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69
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Testelmans D, Nafteux P, Van Cromphaut S, Vrijsen B, Vos R, De Leyn P, Decaluwé H, Van Raemdonck D, Verleden GM, Buyse B. Feasibility of diaphragm pacing in patients after bilateral lung transplantation. Clin Transplant 2017; 31. [DOI: 10.1111/ctr.13134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Dries Testelmans
- Department of Pulmonology; University Hospitals Leuven; Leuven Belgium
| | - Philippe Nafteux
- Department of Thoracic Surgery; University Hospitals Leuven; Leuven Belgium
| | - Sophie Van Cromphaut
- Department of Intensive Care Medicine; University Hospitals Leuven; Leuven Belgium
| | - Bart Vrijsen
- Faculty of Kinesiology and Rehabilitation Sciences; KU Leuven; Leuven Belgium
| | - Robin Vos
- Department of Pulmonology; University Hospitals Leuven; Leuven Belgium
| | - Paul De Leyn
- Department of Thoracic Surgery; University Hospitals Leuven; Leuven Belgium
| | - Herbert Decaluwé
- Department of Thoracic Surgery; University Hospitals Leuven; Leuven Belgium
| | - Dirk Van Raemdonck
- Department of Thoracic Surgery; University Hospitals Leuven; Leuven Belgium
| | - Geert M. Verleden
- Department of Pulmonology; University Hospitals Leuven; Leuven Belgium
| | - Bertien Buyse
- Department of Pulmonology; University Hospitals Leuven; Leuven Belgium
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70
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Smith BK, Falk DJ. Mechanical Ventilation for Duchenne Muscular Dystrophy: Sinner or Saint? Muscle Nerve 2017; 57:353-355. [PMID: 29023941 DOI: 10.1002/mus.25986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Barbara K Smith
- Department of Physical Therapy, University of Florida, Gainesville, Florida, 32610-0154, USA.,Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Darin J Falk
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
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71
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Pardo PS, Lopez MA, Mohamed JS, Boriek AM. Anisotropic mechanosensitive pathways in the diaphragm and their implications in muscular dystrophies. J Muscle Res Cell Motil 2017; 38:437-446. [PMID: 28986699 DOI: 10.1007/s10974-017-9483-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/13/2017] [Indexed: 11/24/2022]
Abstract
The diaphragm is the "respiratory pump;" the muscle that generates pressure to allow ventilation. Diaphragm muscles play a vital function and thus are subjected to continuous mechanical loading. One of its peculiarities is the ability to generate distinct mechanical and biochemical responses depending on the direction through which the mechanical forces applied to it. Contractile forces originated from its contractile components are transmitted to other structural components of its muscle fibers and the surrounding connective tissue. The anisotropic mechanical properties of the diaphragm are translated into biochemical signals that are directionally mechanosensitive by mechanisms that appear to be unique to this muscle. Here, we reviewed the current state of knowledge on the biochemical pathways regulated by mechanical signals emphasizing their anisotropic behavior in the normal diaphragm and analyzed how they are affected in muscular dystrophies.
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Affiliation(s)
- Patricia S Pardo
- Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Michael A Lopez
- Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Junaith S Mohamed
- Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.,Laboratory of Muscle Biology and Sarcopenia, Division of Exercise Physiology, Department of Human Performance, Center for Cardiovascular and Respiratory Sciences, West Virginia University, School of Medicine, Morgantown, WV, 26506, USA
| | - Aladin M Boriek
- Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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Abstract
Advances in intensive care unit (ICU) therapeutics are plentiful and rooted in technological enhancements as well as recognition of patient care priorities. A plethora of new devices and modes are available for use to enhance patient safety and support liberation from mechanical ventilation while preserving oxygenation and carbon dioxide clearance. Increased penetrance of closed loop systems is one means to reduce care variation in appropriate populations. The intelligent design of the ICU space needs to integrate the footprint of that device and the data streaming from it into a coherent whole that supports patient, family, and caregivers.
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Affiliation(s)
- Brian Weiss
- Perelman School of Medicine, University of Pennsylvania, 51 North 39th Street, MOB 1, Philadelphia, PA 19104, USA
| | - Lewis J Kaplan
- Perelman School of Medicine, University of Pennsylvania, 51 North 39th Street, MOB 1, Philadelphia, PA 19104, USA; Surgical Critical Care, Corporal Michael J Crescenz VA Medical Center, 3900 Woodland Avenue, Philadelphia, PA 19104, USA; Division of Trauma, Surgical Critical Care and Emergency Surgery, Perelman School of Medicine, University of Pennsylvania, 51 North 39th Street, MOB 1, Philadelphia, PA 19104, USA.
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73
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Huang D, Ma H, Zhong W, Wang X, Wu Y, Qin T, Wang S, Tan N. Using M-mode ultrasonography to assess diaphragm dysfunction and predict the success of mechanical ventilation weaning in elderly patients. J Thorac Dis 2017; 9:3177-3186. [PMID: 29221294 DOI: 10.21037/jtd.2017.08.16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Ultrasonography (US) is a non-invasive and commonly available bedside diagnostic tool. The aim of this study was to assess the utility of M-mode US on ventilator weaning outcomes in elderly patients. Methods This was a single center, prospective, observational study in patients aged 80 years or older who were in the medical intensive care unit, had undergone mechanical ventilation for >48 hours, and met the criteria for a spontaneous breathing trial (SBT). For 30 minutes at the start of SBT, each hemi-diaphragmatic movement and the velocity of contraction were evaluated by M-mode US. The the area under the receiver operating characteristic curve (AUROC) was calculated to determine the ability for measured variables to predict successful ventilator weaning. Results Forty patients were enrolled and assessed, grouped by those who had US-diagnosed diaphragm dysfunction (DD; 30/40; 75%) and those who did not (10/40; 25%). Patients with DD had a significantly longer total mechanical ventilation duration (536.4±377.05 vs. 250±109.02 hours, P=0.02) and weaning time (425.9±268.31 vs. 216.0±134.22 hours, P=0.002) than patients without DD. Patients with DD also had a higher incidence of weaning failure than patients without DD (24/30 vs. 4/10, P=0.017). Analysis of the receiver operating characteristic (ROC) curve (ROC) curve showed that the optimal cut-off values to predict weaning success were >10.7 mm for the right diaphragmatic movement, and >21.32 mm/s for the right diaphragmatic velocity of contraction; AUROC were 0.839 (95% CI, 0.689-0.936) and 0.833 (95% CI, 0.682-0.932), respectively. The sensitivity, specificity, positive and negative likelihood ratios for predicting weaning success were 83.33% vs. 66.67%, 75.00% vs. 92.86%, 3.33 vs. 9.33, and 0.22 vs. 0.36, for right diaphragmatic movement and diaphragmatic contraction velocity, respectively. Conclusions When assessed by M-mode US, DD appeared to be common in ventilated patients aged 80 years or older and was associated with a higher incidence of weaning failure. Larger right diaphragmatic movements or faster right diaphragmatic contraction velocity appeared to be good predictors of mechanical ventilation weaning success in elderly patients.
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Affiliation(s)
- Daozheng Huang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.,Department of Critical Care Medicine, Guangdong Geriatric Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Huan Ma
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Wenzhao Zhong
- Guangdong Lung Cancer Institute, Guangdong General Hospital and Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Xiaoting Wang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yan Wu
- Department of Critical Care Medicine, Guangdong Geriatric Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Tiehe Qin
- Department of Critical Care Medicine, Guangdong Geriatric Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Shouhong Wang
- Department of Critical Care Medicine, Guangdong Geriatric Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Ning Tan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
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Powers SK, Lynch GS, Murphy KT, Reid MB, Zijdewind I. Disease-Induced Skeletal Muscle Atrophy and Fatigue. Med Sci Sports Exerc 2017; 48:2307-2319. [PMID: 27128663 DOI: 10.1249/mss.0000000000000975] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Numerous health problems, including acute critical illness, cancer, diseases associated with chronic inflammation, and neurological disorders, often result in skeletal muscle weakness and fatigue. Disease-related muscle atrophy and fatigue is an important clinical problem because acquired skeletal muscle weakness can increase the duration of hospitalization, result in exercise limitation, and contribute to a poor quality of life. Importantly, skeletal muscle atrophy is also associated with increased morbidity and mortality of patients. Therefore, improving our understanding of the mechanism(s) responsible for skeletal muscle weakness and fatigue in patients is a required first step to develop clinical protocols to prevent these skeletal muscle problems. This review will highlight the consequences and potential mechanisms responsible for skeletal muscle atrophy and fatigue in patients experiencing acute critical illness, cancer, chronic inflammatory diseases, and neurological disorders.
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Affiliation(s)
- Scott K Powers
- 1Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL; 2Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Victoria, AUSTRALIA; and 3Medical Physiology, Department of Neuroscience, University Medical Center Groningen, Groningen, THE NETHERLANDS
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Lee EP, Hsia SH, Hsiao HF, Chen MC, Lin JJ, Chan OW, Lin CY, Yang MC, Liao SL, Lai SH. Evaluation of diaphragmatic function in mechanically ventilated children: An ultrasound study. PLoS One 2017; 12:e0183560. [PMID: 28829819 PMCID: PMC5567657 DOI: 10.1371/journal.pone.0183560] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/07/2017] [Indexed: 11/23/2022] Open
Abstract
Background The recovery of diaphragmatic function is vital for successful extubation from mechanical ventilation. Recent studies have detected diaphragm atrophy in ventilated adults by using ultrasound, but no similar report has been conducted in children. In the current study, we hypothesized that mechanically ventilated children may also develop diaphragm atrophy and diaphragmatic dysfunction. Materials and methods Children who were admitted to the pediatric intensive care unit and were newly intubated for mechanical ventilation were enrolled into this prospective case–control study. Diaphragm ultrasound assessments were performed daily to evaluate diaphragmatic function in the enrolled children until their discharge from the pediatric intensive care unit. Diaphragm thickness and the diaphragmatic thickening fraction (DTF) were measured through these assessments. Results A total of 31 patients were enrolled, and overall, 1389 ultrasound assessments were performed. Immediately after intubation, the initial diaphragm thickness and DTF were measured to be 1.94 ± 0.44 mm and 25.85% ± 3.29%, respectively. In the first 24 hours of mechanical ventilation, diaphragm thickness and the DTF decreased substantially and decreased gradually thereafter. After extubation, the DTF was significantly different between the successful and failed extubation groups (P < 0.001), and a DTF value of <17% was associated with extubation failure. Conclusions Diaphragm ultrasound is a noninvasive method for measuring diaphragmatic function in mechanically ventilated children. In this study, significant diaphragm atrophy and a decreased DTF were observed within 24 hours of mechanical ventilation. The recovery of diaphragm thickness and the DTF may be a potential predictor of successful extubation from mechanical ventilation.
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Affiliation(s)
- En-Pei Lee
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shao-Hsuan Hsia
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsiu-Feng Hsiao
- Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Min-Chi Chen
- Department of Hematology and Oncology, Chang Gung Memorial Hospital, Chiayi, Taiwan
- Department of Public Health and Biostatistics Consulting Center, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Jainn-Jim Lin
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Division of Pediatric Neurology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Oi-Wa Chan
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chia-Ying Lin
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Mei-Chin Yang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Sui-Ling Liao
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan
| | - Shen-Hao Lai
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Division of Pediatric Pulmonology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- * E-mail:
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76
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Powers SK. Exercise: Teaching myocytes new tricks. J Appl Physiol (1985) 2017; 123:460-472. [PMID: 28572498 DOI: 10.1152/japplphysiol.00418.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/26/2017] [Accepted: 05/28/2017] [Indexed: 12/31/2022] Open
Abstract
Endurance exercise training promotes numerous cellular adaptations in both cardiac myocytes and skeletal muscle fibers. For example, exercise training fosters changes in mitochondrial function due to increased mitochondrial protein expression and accelerated mitochondrial turnover. Additionally, endurance exercise training alters the abundance of numerous cytosolic and mitochondrial proteins in both cardiac and skeletal muscle myocytes, resulting in a protective phenotype in the active fibers; this exercise-induced protection of cardiac and skeletal muscle fibers is often referred to as "exercise preconditioning." As few as 3-5 consecutive days of endurance exercise training result in a preconditioned cardiac phenotype that is sheltered against ischemia-reperfusion-induced injury. Similarly, endurance exercise training results in preconditioned skeletal muscle fibers that are resistant to a variety of stresses (e.g., heat stress, exercise-induced oxidative stress, and inactivity-induced atrophy). Many studies have probed the mechanisms responsible for exercise-induced preconditioning of cardiac and skeletal muscle fibers; these studies are important, because they provide an improved understanding of the biochemical mechanisms responsible for exercise-induced preconditioning, which has the potential to lead to innovative pharmacological therapies aimed at minimizing stress-induced injury to cardiac and skeletal muscle. This review summarizes the development of exercise-induced protection of cardiac myocytes and skeletal muscle fibers and highlights the putative mechanisms responsible for exercise-induced protection in the heart and skeletal muscles.
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Affiliation(s)
- Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
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77
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Sepsis Pathophysiology, Chronic Critical Illness, and Persistent Inflammation-Immunosuppression and Catabolism Syndrome. Crit Care Med 2017; 45:253-262. [PMID: 27632674 DOI: 10.1097/ccm.0000000000002074] [Citation(s) in RCA: 322] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To provide an appraisal of the evolving paradigms in the pathophysiology of sepsis and propose the evolution of a new phenotype of critically ill patients, its potential underlying mechanism, and its implications for the future of sepsis management and research. DESIGN Literature search using PubMed, MEDLINE, EMBASE, and Google Scholar. MEASUREMENTS AND MAIN RESULTS Sepsis remains one of the most debilitating and expensive illnesses, and its prevalence is not declining. What is changing is our definition(s), its clinical course, and how we manage the septic patient. Once thought to be predominantly a syndrome of over exuberant inflammation, sepsis is now recognized as a syndrome of aberrant host protective immunity. Earlier recognition and compliance with treatment bundles has fortunately led to a decline in multiple organ failure and in-hospital mortality. Unfortunately, more and more sepsis patients, especially the aged, are suffering chronic critical illness, rarely fully recover, and often experience an indolent death. Patients with chronic critical illness often exhibit "a persistent inflammation-immunosuppression and catabolism syndrome," and it is proposed here that this state of persisting inflammation, immunosuppression and catabolism contributes to many of these adverse clinical outcomes. The underlying cause of inflammation-immunosuppression and catabolism syndrome is currently unknown, but there is increasing evidence that altered myelopoiesis, reduced effector T-cell function, and expansion of immature myeloid-derived suppressor cells are all contributory. CONCLUSIONS Although newer therapeutic interventions are targeting the inflammatory, the immunosuppressive, and the protein catabolic responses individually, successful treatment of the septic patient with chronic critical illness and persistent inflammation-immunosuppression and catabolism syndrome may require a more complementary approach.
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Sollanek KJ, Burniston JG, Kavazis AN, Morton AB, Wiggs MP, Ahn B, Smuder AJ, Powers SK. Global Proteome Changes in the Rat Diaphragm Induced by Endurance Exercise Training. PLoS One 2017; 12:e0171007. [PMID: 28135290 PMCID: PMC5279855 DOI: 10.1371/journal.pone.0171007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 01/13/2017] [Indexed: 01/15/2023] Open
Abstract
Mechanical ventilation (MV) is a life-saving intervention for many critically ill patients. Unfortunately, prolonged MV results in the rapid development of diaphragmatic atrophy and weakness. Importantly, endurance exercise training results in a diaphragmatic phenotype that is protected against ventilator-induced diaphragmatic atrophy and weakness. The mechanisms responsible for this exercise-induced protection against ventilator-induced diaphragmatic atrophy remain unknown. Therefore, to investigate exercise-induced changes in diaphragm muscle proteins, we compared the diaphragmatic proteome from sedentary and exercise-trained rats. Specifically, using label-free liquid chromatography-mass spectrometry, we performed a proteomics analysis of both soluble proteins and mitochondrial proteins isolated from diaphragm muscle. The total number of diaphragm proteins profiled in the soluble protein fraction and mitochondrial protein fraction were 813 and 732, respectively. Endurance exercise training significantly (P<0.05, FDR <10%) altered the abundance of 70 proteins in the soluble diaphragm proteome and 25 proteins of the mitochondrial proteome. In particular, key cytoprotective proteins that increased in relative abundance following exercise training included mitochondrial fission process 1 (Mtfp1; MTP18), 3-mercaptopyruvate sulfurtransferase (3MPST), microsomal glutathione S-transferase 3 (Mgst3; GST-III), and heat shock protein 70 kDa protein 1A/1B (HSP70). While these proteins are known to be cytoprotective in several cell types, the cyto-protective roles of these proteins have yet to be fully elucidated in diaphragm muscle fibers. Based upon these important findings, future experiments can now determine which of these diaphragmatic proteins are sufficient and/or required to promote exercise-induced protection against inactivity-induced muscle atrophy.
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Affiliation(s)
- Kurt J. Sollanek
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Jatin G. Burniston
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Andreas N. Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States of America
| | - Aaron B. Morton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Michael P. Wiggs
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Bumsoo Ahn
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Ashley J. Smuder
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Scott K. Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
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Orde SR, Boon AJ, Firth DG, Villarraga HR, Sekiguchi H. Use of Angle-Independent M-Mode Sonography for Assessment of Diaphragm Displacement. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2016; 35:2615-2621. [PMID: 27872418 DOI: 10.7863/ultra.15.11100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/11/2016] [Accepted: 03/01/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVES Sonographic assessment of diaphragm displacement has conventionally been conducted with M-mode sonography via an anterior subcostal approach. This method is subject to measurement errors when diaphragm displacement is not in line with the M-mode plane. We aimed to compare measurements obtained by offline angle-independent (anatomic) M-mode sonography with conventional M-mode sonography. METHODS Fifty healthy adults were imaged with conventional and angle-independent M-mode sonography of the bilateral hemidiaphragms at 60% maximal inspiratory capacity using an inspiratory spirometer. RESULTS Left hemidiaphragm displacement was successfully imaged by conventional M-mode sonography in only 70% (n = 35), as lung expansion obscured imaging, whereas 92% (n = 46) were assessable by angle-independent M-mode sonography. All right hemidiaphragm displacement could be assessed. Conventional M-mode results were higher than angle-independent M-mode results on the right (mean ± SD, 4.9 ± 1.4 versus 4.6 ± 1.2 cm, respectively; P= .003) and left (5.4 ± 1.3 versus 4.6 ± 1.0 cm; P < .001). Displacement values were different for right versus left hemidiaphragms on conventional M-mode sonography (mean difference, 0.6 ± 0.2 cm; P = .005), with only mild agreement (R2 = 0.35; P < .001). There was no laterality seen in the diaphragm displacement on angle-independent M-mode sonography (mean difference, 0.1 ± 0.1 cm; P = .47), with good agreement (R2 = 0.76; P < .001). CONCLUSIONS Angle-independent M-mode sonography leads to better visualization and assessment of the left hemidiaphragm. It records lower displacement than conventional M-mode sonography in the bilateral diaphragms, likely because of fewer orientation and translation errors. Future study is indicated to assess the clinical utility of angle-independent M-mode sonography in a population with diaphragm dysfunction.
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Affiliation(s)
- Sam R Orde
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota USA
- Department of Intensive Care, Nepean Hospital, Sydney, New South Wales, Australia
| | - Andrea J Boon
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota USA
| | - Daniel G Firth
- Department of Family Medicine, Mayo Clinic, Rochester, Minnesota USA
| | | | - Hiroshi Sekiguchi
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota USA
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Jorens PG, Schepens T. Ultrasound: a novel translational tool to study diaphragmatic dysfunction in critical illness. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:515. [PMID: 28149877 DOI: 10.21037/atm.2016.12.49] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Philippe G Jorens
- Department of Critical Care Medicine, Antwerp University Hospital, University of Antwerp, B-2650 Edegem, Belgium
| | - Tom Schepens
- Department of Critical Care Medicine, Antwerp University Hospital, University of Antwerp, B-2650 Edegem, Belgium
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81
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Wilcox SR. Corticosteroids and neuromuscular blockers in development of critical illness neuromuscular abnormalities: A historical review. J Crit Care 2016; 37:149-155. [PMID: 27736708 DOI: 10.1016/j.jcrc.2016.09.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 08/31/2016] [Accepted: 09/20/2016] [Indexed: 01/28/2023]
Abstract
Weakness is common in critically ill patients, associated with prolonged mechanical ventilation and increased mortality. Corticosteroids and neuromuscular blockade (NMB) administration have been implicated as etiologies of acquired weakness in the intensive care unit. Medical literature since the 1970s is replete with case reports and small case series of patients with weakness after receiving high-dose corticosteroids, prolonged NMB, or both. Several risk factors for weakness appear in the early literature, including large doses of steroids, the dose and duration of NMB, hyperglycemia, and the duration of mechanical ventilation. With improved quality of data, however, the association between weakness and steroids or NMB wanes. This may reflect changes in clinical practice, such as a reduction in steroid dosing, use of cisatracurium besylate instead of aminosteroid NMBs, improved glycemic control, or trends in minimizing mechanical ventilatory support. Thus, based on the most recent and high-quality literature, neither corticosteroids in commonly used doses nor NMB is associated with increased duration of mechanical ventilation, the greatest morbidity of weakness. Minimizing ventilator support as soon as the patient's condition allows may be associated with a reduction in weakness-related morbidity.
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Affiliation(s)
- Susan R Wilcox
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine and Division of Emergency Medicine, Department of Medicine, Medical University of South Carolina, Charleston, SC.
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82
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Dot I, Pérez-Teran P, Samper MA, Masclans JR. Diaphragm Dysfunction in Mechanically Ventilated Patients. Arch Bronconeumol 2016; 53:150-156. [PMID: 27553431 DOI: 10.1016/j.arbres.2016.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/04/2016] [Accepted: 07/17/2016] [Indexed: 12/14/2022]
Abstract
Muscle involvement is found in most critical patients admitted to the intensive care unit (ICU). Diaphragmatic muscle alteration, initially included in this category, has been differentiated in recent years, and a specific type of muscular dysfunction has been shown to occur in patients undergoing mechanical ventilation. We found this muscle dysfunction to appear in this subgroup of patients shortly after the start of mechanical ventilation, observing it to be mainly associated with certain control modes, and also with sepsis and/or multi-organ failure. Although the specific etiology of process is unknown, the muscle presents oxidative stress and mitochondrial changes. These cause changes in protein turnover, resulting in atrophy and impaired contractility, and leading to impaired functionality. The term 'ventilator-induced diaphragm dysfunction' was first coined by Vassilakopoulos et al. in 2004, and this phenomenon, along with injury cause by over-distention of the lung and barotrauma, represents a challenge in the daily life of ventilated patients. Diaphragmatic dysfunction affects prognosis by delaying extubation, prolonging hospital stay, and impairing the quality of life of these patients in the years following hospital discharge. Ultrasound, a non-invasive technique that is readily available in most ICUs, could be used to diagnose this condition promptly, thus preventing delays in starting rehabilitation and positively influencing prognosis in these patients.
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Affiliation(s)
- Irene Dot
- Servicio de Medicina Intensiva, Hospital del Mar-Parc de Salut Mar de Barcelona, Barcelona, España; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM)-GREPAC, Barcelona, España
| | - Purificación Pérez-Teran
- Servicio de Medicina Intensiva, Hospital del Mar-Parc de Salut Mar de Barcelona, Barcelona, España; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM)-GREPAC, Barcelona, España
| | - Manuel-Andrés Samper
- Servicio de Medicina Intensiva, Hospital del Mar-Parc de Salut Mar de Barcelona, Barcelona, España; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM)-GREPAC, Barcelona, España
| | - Joan-Ramon Masclans
- Servicio de Medicina Intensiva, Hospital del Mar-Parc de Salut Mar de Barcelona, Barcelona, España; Institut Hospital del Mar d'Investigacions Mèdiques (IMIM)-GREPAC, Barcelona, España; Universitat Pompeu Fabra, Barcelona, España; CIBERES, España.
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83
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Sigurta' A, Zambelli V, Bellani G. Renin-angiotensin system in ventilator-induced diaphragmatic dysfunction: Potential protective role of Angiotensin (1-7). Med Hypotheses 2016; 94:132-7. [PMID: 27515219 DOI: 10.1016/j.mehy.2016.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 12/14/2022]
Abstract
Ventilator-induced diaphragmatic dysfunction is a feared complication of mechanical ventilation that adversely affects the outcome of intensive care patients. Human and animal studies demonstrate atrophy and ultrastructural alteration of diaphragmatic muscular fibers attributable to increased oxidative stress, depression of the anabolic pathway regulated by Insulin-like growing factor 1 and increased proteolysis. The renin-angiotensin system, through its main peptide Angiotensin II, plays a major role in skeletal muscle diseases, mainly increasing oxidative stress and inducing insulin resistance, atrophy and fibrosis. Conversely, its counter-regulatory peptide Angiotensin (1-7) has a protective role in these processes. Recent data on rodent models show that renin-angiotensin system is activated after mechanical ventilation and that infusion of Angiotensin II induces diaphragmatic skeletal muscle atrophy. Given: (A) common pathways shared by ventilator-induced diaphragmatic dysfunction and skeletal muscle pathology induced by renin-angiotensin system, (B) evidences of an involvement of renin-angiotensin system in diaphragm atrophy and dysfunction, we hypothesize that renin-angiotensin system plays an important role in ventilator-induced diaphragmatic dysfunction, while Angiotensin (1-7) can have a protective effect on this pathological process. The activation of renin-angiotensin system in ventilator-induced diaphragmatic dysfunction can be demonstrated by quantification of its main components in the diaphragm of ventilated humans or animals. The infusion of Angiotensin (1-7) in an established rodent model of ventilator-induced diaphragmatic dysfunction can be used to test its potential protective role, that can be further confirmed with the infusion of Angiotensin (1-7) antagonists like A-779. Verifying this hypothesis can help in understanding the processes involved in ventilator-induced diaphragmatic dysfunction pathophysiology and open new possibilities for its prevention and treatment.
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Affiliation(s)
- Anna Sigurta'
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
| | - Vanessa Zambelli
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Giacomo Bellani
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy; Department of Emergency, San Gerardo Hospital, Monza, Italy
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Li LF, Chang YL, Chen NH, Wang CY, Chang GJ, Lin MC, Chang CH, Huang CC, Chuang JH, Yang YP, Chiou SH, Liu YY. Inhibition of Src and forkhead box O1 signaling by induced pluripotent stem-cell therapy attenuates hyperoxia-augmented ventilator-induced diaphragm dysfunction. Transl Res 2016; 173:131-147.e1. [PMID: 27055225 DOI: 10.1016/j.trsl.2016.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/13/2016] [Accepted: 03/15/2016] [Indexed: 11/19/2022]
Abstract
Mechanical ventilation (MV) with hyperoxia is required for providing life support to patients with acute lung injury (ALI). However, MV may cause diaphragm weakness through muscle injury and atrophy, an effect termed ventilator-induced diaphragm dysfunction (VIDD). Src protein tyrosine kinase and class O of forkhead box 1 (FoxO1) mediate acute inflammatory responses and muscle protein degradation induced by oxidative stress. Induced pluripotent stem cells (iPSCs) have been reported to improve hyperoxia-augmented ALI; however, the mechanisms regulating the interactions among VIDD, hyperoxia, and iPSCs are unclear. In this study, we hypothesized that iPSC therapy can ameliorate hyperoxia-augmented VIDD by suppressing the Src-FoxO1 pathway. Male C57BL/6 mice, either wild-type or Src-deficient, aged between 6 and 8 weeks were exposed to MV (6 or 10 mL/kg) with or without hyperoxia for 2-8 h after the administration of 5 × 10(7) cells/kg Oct4/Sox2/Parp1 mouse iPSCs or iPSC-derived conditioned medium (iPSC-CM). Nonventilated mice were used as controls. MV during hyperoxia aggravated VIDD, as demonstrated by the increases in Src activation, FoxO1 dephosphorylation, malondialdehyde, caspase-3, atrogin-1 and muscle ring finger-1 production, microtubule-associated protein light chain 3-II, disorganized myofibrils, disrupted mitochondria, autophagy, and myonuclear apoptosis; however, MV with hyperoxia reduced mitochondrial cytochrome C, diaphragm muscle fiber size, and contractility (P < 0.05). Hyperoxia-exacerbated VIDD was attenuated in Src-deficient mice and by iPSCs and iPSC-CM (P < 0.05). Our data indicate that iPSC therapy attenuates MV-induced diaphragmatic injury that occurs during hyperoxia-augmented VIDD by inhibiting the Src-FoxO1 signaling pathway.
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Affiliation(s)
- Li-Fu Li
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yuh-Lih Chang
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ning-Hung Chen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chien-Ying Wang
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Gwo-Jyh Chang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Meng-Chih Lin
- Division of Pulmonary and Critical Care Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Chih-Hao Chang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan
| | - Chung-Chi Huang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jen-Hua Chuang
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Pin Yang
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Hwa Chiou
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yung-Yang Liu
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Chest Department, Taipei Veterans General Hospital, Taipei, Taiwan.
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85
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Kuo NY, Tu ML, Hung TY, Liu SF, Chung YH, Lin MC, Wu CC. A randomized clinical trial of neurally adjusted ventilatory assist versus conventional weaning mode in patients with COPD and prolonged mechanical ventilation. Int J Chron Obstruct Pulmon Dis 2016; 11:945-51. [PMID: 27274216 PMCID: PMC4869614 DOI: 10.2147/copd.s103213] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Patient-ventilator asynchrony is a common problem in mechanically ventilated patients; the problem is especially obvious in COPD. Neutrally adjusted ventilatory assist (NAVA) can improve patient-ventilator asynchrony; however, the effect in COPD patients with prolonged mechanical ventilation is still unknown. The goals of this study are to evaluate the effect of NAVA and conventional weaning mode in patients with COPD during prolonged mechanical ventilation. METHODS The study enrolled a total of 33 COPD patients with ventilator dependency for more than 21 days in the weaning center. A diaphragm electrical activity (Edi) catheter was inserted in patients within 24 hours after admission to the respiratory care center, and patients were randomly allocated to NAVA or conventional group. A spontaneous breathing trial was performed every 24 hours. The results correlated with the clinical parameters. RESULTS There were significantly higher asynchrony incidence rates in the whole group after using Edi catheter (before vs post-Edi catheter insertion =60.6% vs 87.9%, P<0.001). Asynchrony index: before vs post-Edi catheter insertion =7.4%±8.5% vs 13.2%±13.5%, P<0.01. Asynchrony incidence: NAVA vs conventional =0% vs 84.2%, P<0.001. Asynchrony index: NAVA vs conventional =0 vs 11.9±11.2 (breath %), P<0.001. The most common asynchrony events were ineffective trigger and delayed trigger. CONCLUSION Compared to conventional mode, NAVA mode can significantly enhance respiratory monitoring and improve patient-ventilator interaction in COPD patients with prolonged mechanical ventilation in respiratory care center.
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Affiliation(s)
- Nai-Ying Kuo
- Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital, Chiayi, Taiwan
- Kaohsiung Medical University, Chiayi, Taiwan
| | - Mei-Lien Tu
- Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital, Chiayi, Taiwan
- Respiratory Care, Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Tsai-Yi Hung
- Department of Respiratory Therapy, Kaohsiung Chang Gung Memorial Hospital, Chiayi, Taiwan
| | - Shih-Feng Liu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yu-Hsiu Chung
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Meng-Chih Lin
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chao-Chien Wu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
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86
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Bloise FF, van der Spek AH, Surovtseva OV, Ortiga-Carvalho TM, Fliers E, Boelen A. Differential Effects of Sepsis and Chronic Inflammation on Diaphragm Muscle Fiber Type, Thyroid Hormone Metabolism, and Mitochondrial Function. Thyroid 2016; 26:600-9. [PMID: 26892873 DOI: 10.1089/thy.2015.0536] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The diaphragm is the main respiratory muscle, and its function is compromised during severe illness. Altered local thyroid hormone (TH) metabolism may be a determinant of impaired muscle function during illness. METHODS This study investigates the effects of bacterial sepsis and chronic inflammation on muscle fiber type, local TH metabolism, and mitochondrial function in the diaphragm. Two mouse models were used: sepsis induced by S. pneumoniae infection or chronic inflammation induced by subcutaneous turpentine injection. In vitro, the effect of bacterial endotoxin (LPS) on mitochondrial function in C2C12 myotubes was studied. RESULTS Sepsis induced a transient increase in the fiber type I profile and increased Dio3 expression while decreasing Dio2, Thra1, and Slc16a2 expression. Triiodothyronine positively regulated genes Tnni2 and Myog were decreased, indicating reduced TH signaling in the diaphragm. In contrast, chronic inflammation increased the fiber type II profile in the diaphragm as well as Thra1, Thrb1, and Myog expression while decreasing Dio3 expression, suggesting increased TH responsiveness during chronic inflammation. LPS-stimulated C2C12 myotubes showed decreased Dio2 expression and reduced basal oxygen consumption as well as non-mitochondrial respiration. The same respiratory profile was induced by Dio2 knockdown in myotubes. CONCLUSIONS The in vivo results show differential effects of sepsis and chronic inflammation on diaphragm muscle fiber type, TH metabolism, and mitochondrial function, while the in vitro results point to a causal role for altered TH metabolism in functional muscle impairment. These findings may be relevant for the pathogenesis of impaired respiratory function in critical illness.
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Affiliation(s)
- Flavia F Bloise
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
- 2 Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Anne H van der Spek
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Olga V Surovtseva
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Tania Maria Ortiga-Carvalho
- 2 Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Eric Fliers
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
| | - Anita Boelen
- 1 Department of Endocrinology and Metabolism, Academic Medical Centre, University of Amsterdam , Amsterdam, The Netherlands
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87
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Volpe MS, Aleixo AA, Almeida PRMND. Influence of inspiratory muscle training on weaning patients from mechanical ventilation: a systematic review. FISIOTERAPIA EM MOVIMENTO 2016. [DOI: 10.1590/0103-5150.029.001.ar02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract Introduction: The inability of respiratory muscles to generate force and endurance is recognized as an important cause of failure in weaning patients from invasive mechanical ventilation (IMV). Thus, inspiratory muscle training (IMT) might be an interesting treatment option for patients with prolonged IMV weaning. Objective: The aim of this systematic literature review was to evaluate the effectiveness of inspiratory muscle training in weaning patients from mechanical ventilation and to identify the most effective type of training for this particular purpose. Methods: We searched PubMed, LILACS, PEDro and Web of Science for randomized clinical trials published in English or Portuguese from January 1990 until March 2015. Results: Eighty-nine studies were identified of which five were selected. A total of 267 patients participated in the five randomized clinical trials analyzed here. IMV duration before onset of training varied greatly among subjects. Three studies performed IMT using a threshold device and two studies used adjustments of ventilator pressure sensitivity. Four studies have shown that IMT resulted in a significant increase in inspiratory maximal pressure. Only two studies, however, have reported that IMT resulted in higher success rates in weaning patients from IMV. One study has found that patients showed a shorter ventilator weaning duration after IMT. Conclusion: IMT using pressure threshold devices results in increased inspiratory muscle strength and can therefore be considered a more effective treatment option and with the potential to optimize ventilator weaning success in patients at risk of prolonged IMV.
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Talbert EE, Smuder AJ, Kwon OS, Sollanek KJ, Wiggs MP, Powers SK. Blockage of the Ryanodine Receptor via Azumolene Does Not Prevent Mechanical Ventilation-Induced Diaphragm Atrophy. PLoS One 2016; 11:e0148161. [PMID: 26849371 PMCID: PMC4744044 DOI: 10.1371/journal.pone.0148161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 01/13/2016] [Indexed: 11/18/2022] Open
Abstract
Mechanical ventilation (MV) is a life-saving intervention for patients in respiratory failure. However, prolonged MV causes the rapid development of diaphragm muscle atrophy, and diaphragmatic weakness may contribute to difficult weaning from MV. Therefore, developing a therapeutic countermeasure to protect against MV-induced diaphragmatic atrophy is important. MV-induced diaphragm atrophy is due, at least in part, to increased production of reactive oxygen species (ROS) from diaphragm mitochondria and the activation of key muscle proteases (i.e., calpain and caspase-3). In this regard, leakage of calcium through the ryanodine receptor (RyR1) in diaphragm muscle fibers during MV could result in increased mitochondrial ROS emission, protease activation, and diaphragm atrophy. Therefore, these experiments tested the hypothesis that a pharmacological blockade of the RyR1 in diaphragm fibers with azumolene (AZ) would prevent MV-induced increases in mitochondrial ROS production, protease activation, and diaphragmatic atrophy. Adult female Sprague-Dawley rats underwent 12 hours of full-support MV while receiving either AZ or vehicle. At the end of the experiment, mitochondrial ROS emission, protease activation, and fiber cross-sectional area were determined in diaphragm muscle fibers. Decreases in muscle force production following MV indicate that the diaphragm took up a sufficient quantity of AZ to block calcium release through the RyR1. However, our findings reveal that AZ treatment did not prevent the MV-induced increase in mitochondrial ROS emission or protease activation in the diaphragm. Importantly, AZ treatment did not prevent MV-induced diaphragm fiber atrophy. Thus, pharmacological inhibition of the RyR1 in diaphragm muscle fibers is not sufficient to prevent MV-induced diaphragm atrophy.
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Affiliation(s)
- Erin E. Talbert
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Ashley J. Smuder
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Oh Sung Kwon
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Kurt J. Sollanek
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Michael P. Wiggs
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Scott K. Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
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89
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Kalamgi RC, Larsson L. Mechanical Signaling in the Pathophysiology of Critical Illness Myopathy. Front Physiol 2016; 7:23. [PMID: 26869939 PMCID: PMC4740381 DOI: 10.3389/fphys.2016.00023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/18/2016] [Indexed: 12/14/2022] Open
Abstract
The complete loss of mechanical stimuli of skeletal muscles, i.e., the loss of external strain, related to weight bearing, and internal strain, related to the contraction of muscle cells, is uniquely observed in pharmacologically paralyzed or deeply sedated mechanically ventilated intensive care unit (ICU) patients. The preferential loss of myosin and myosin associated proteins in limb and trunk muscles is a significant characteristic of critical illness myopathy (CIM) which separates CIM from other types of acquired muscle weaknesses in ICU patients. Mechanical silencing is an important factor triggering CIM. Microgravity or ground based microgravity models form the basis of research on the effect of muscle unloading-reloading, but the mechanisms and effects may differ from the ICU conditions. In order to understand how mechanical tension regulates muscle mass, it is critical to know how muscles sense mechanical information and convert stimulus to intracellular biochemical actions and changes in gene expression, a process called cellular mechanotransduction. In adult skeletal muscles and muscle fibers, this process may differ, the same stimulus can cause divergent response and the same fiber type may undergo opposite changes in different muscles. Skeletal muscle contains multiple types of mechano-sensors and numerous structures that can be affected differently and hence respond differently in distinct muscles.
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Affiliation(s)
- Rebeca C Kalamgi
- Basic and Clinical Muscle Biology, Department of Physiology and Pharmacology, Karolinska Institutet Stockholm, Sweden
| | - Lars Larsson
- Basic and Clinical Muscle Biology, Department of Physiology and Pharmacology, Karolinska InstitutetStockholm, Sweden; Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska InstitutetStockholm, Sweden
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Gillis TE, Klaiman JM, Foster A, Platt MJ, Huber JS, Corso MY, Simpson JA. Dissecting the role of the myofilament in diaphragm dysfunction during the development of heart failure in mice. Am J Physiol Heart Circ Physiol 2015; 310:H572-86. [PMID: 26702144 DOI: 10.1152/ajpheart.00773.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/21/2015] [Indexed: 11/22/2022]
Abstract
Dyspnea and reduced exercise capacity, caused, in part, by respiratory muscle dysfunction, are common symptoms in patients with heart failure (HF). However, the etiology of diaphragmatic dysfunction has not been identified. To investigate the effects of HF on diaphragmatic function, models of HF were surgically induced in CD-1 mice by transverse aortic constriction (TAC) and acute myocardial infarction (AMI), respectively. Assessment of myocardial function, isolated diaphragmatic strip function, myofilament force-pCa relationship, and phosphorylation status of myofilament proteins was performed at either 2 or 18 wk postsurgery. Echocardiography and invasive hemodynamics revealed development of HF by 18 wk postsurgery in both models. In vitro diaphragmatic force production was preserved in all groups while morphometric analysis revealed diaphragmatic atrophy and fibrosis in 18 wk TAC and AMI groups. Isometric force-pCa measurements of myofilament preparations revealed reduced Ca(2+) sensitivity of force generation and force generation at half-maximum and maximum Ca(2+) activation in 18 wk TAC. The rate of force redevelopment (ktr) was reduced in all HF groups at high levels of Ca(2+) activation. Finally, there were significant changes in the myofilament phosphorylation status of the 18 wk TAC group. This includes a decrease in the phosphorylation of troponin T, desmin, myosin light chain (MLC) 1, and MLC 2 as well as a shift in myosin isoforms. These results indicate that there are multiple changes in diaphragmatic myofilament function, which are specific to the type and stage of HF and occur before overt impairment of in vitro force production.
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Affiliation(s)
- Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada; Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and
| | - Jordan M Klaiman
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada; Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and
| | - Andrew Foster
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mathew J Platt
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jason S Huber
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Melissa Y Corso
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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91
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Carson JA, Hardee JP, VanderVeen BN. The emerging role of skeletal muscle oxidative metabolism as a biological target and cellular regulator of cancer-induced muscle wasting. Semin Cell Dev Biol 2015; 54:53-67. [PMID: 26593326 DOI: 10.1016/j.semcdb.2015.11.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/12/2015] [Indexed: 12/17/2022]
Abstract
While skeletal muscle mass is an established primary outcome related to understanding cancer cachexia mechanisms, considerable gaps exist in our understanding of muscle biochemical and functional properties that have recognized roles in systemic health. Skeletal muscle quality is a classification beyond mass, and is aligned with muscle's metabolic capacity and substrate utilization flexibility. This supplies an additional role for the mitochondria in cancer-induced muscle wasting. While the historical assessment of mitochondria content and function during cancer-induced muscle loss was closely aligned with energy flux and wasting susceptibility, this understanding has expanded to link mitochondria dysfunction to cellular processes regulating myofiber wasting. The primary objective of this article is to highlight muscle mitochondria and oxidative metabolism as a biological target of cancer cachexia and also as a cellular regulator of cancer-induced muscle wasting. Initially, we examine the role of muscle metabolic phenotype and mitochondria content in cancer-induced wasting susceptibility. We then assess the evidence for cancer-induced regulation of skeletal muscle mitochondrial biogenesis, dynamics, mitophagy, and oxidative stress. In addition, we discuss environments associated with cancer cachexia that can impact the regulation of skeletal muscle oxidative metabolism. The article also examines the role of cytokine-mediated regulation of mitochondria function, followed by the potential role of cancer-induced hypogonadism. Lastly, a role for decreased muscle use in cancer-induced mitochondrial dysfunction is reviewed.
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Affiliation(s)
- James A Carson
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, 921 Assembly St., Columbia, SC, 29208, USA.
| | - Justin P Hardee
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, 921 Assembly St., Columbia, SC, 29208, USA
| | - Brandon N VanderVeen
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, 921 Assembly St., Columbia, SC, 29208, USA
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92
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Yoshihara T, Ichinoseki-Sekine N, Kakigi R, Tsuzuki T, Sugiura T, Powers SK, Naito H. Repeated exposure to heat stress results in a diaphragm phenotype that resists ventilator-induced diaphragm dysfunction. J Appl Physiol (1985) 2015; 119:1023-31. [DOI: 10.1152/japplphysiol.00438.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/15/2015] [Indexed: 01/08/2023] Open
Abstract
Controlled mechanical ventilation (CMV) is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged mechanical ventilation (MV) results in diaphragmatic atrophy and contractile dysfunction, both of which are predicted to contribute to problems in weaning patients from the ventilator. Therefore, developing a strategy to protect the diaphragm against ventilator-induced weakness is important. We tested the hypothesis that repeated bouts of heat stress result in diaphragm resistance against CMV-induced atrophy and contractile dysfunction. Male Wistar rats were randomly divided into six experimental groups: 1) control; 2) single bout of whole body heat stress; 3) repeated bouts of whole body heat stress; 4) 12 h CMV; 5) single bout of whole body heat stress 24 h before CMV; and 6) repeated bouts of whole body heat stress 1, 3, and 5 days before 12 h of CMV. Our results revealed that repeated bouts of heat stress resulted in increased levels of heat shock protein 72 in the diaphragm and protection against both CMV-induced diaphragmatic atrophy and contractile dysfunction at submaximal stimulation frequencies. The specific mechanisms responsible for this protection remain unclear: this heat stress-induced protection against CMV-induced diaphragmatic atrophy and weakness may be partially due to reduced diaphragmatic oxidative stress, diminished activation of signal transducer/transcriptional activator-3, lower caspase-3 activation, and decreased autophagy in the diaphragm.
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Affiliation(s)
- Toshinori Yoshihara
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
- JSPS Research Fellow, Tokyo, Japan
| | - Noriko Ichinoseki-Sekine
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
- Faculty of Liberal Arts, The Open University of Japan, Chiba, Japan
| | - Ryo Kakigi
- Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Takamasa Tsuzuki
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
- JSPS Research Fellow, Tokyo, Japan
| | - Takao Sugiura
- Faculty of Education, Yamaguchi University, Yamaguchi, Japan; and
| | - Scott K. Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Hisashi Naito
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
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93
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Partial Support Ventilation and Mitochondrial-Targeted Antioxidants Protect against Ventilator-Induced Decreases in Diaphragm Muscle Protein Synthesis. PLoS One 2015; 10:e0137693. [PMID: 26361212 PMCID: PMC4567376 DOI: 10.1371/journal.pone.0137693] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/19/2015] [Indexed: 01/08/2023] Open
Abstract
Mechanical ventilation (MV) is a life-saving intervention in patients in respiratory failure. Unfortunately, prolonged MV results in the rapid development of diaphragm atrophy and weakness. MV-induced diaphragmatic weakness is significant because inspiratory muscle dysfunction is a risk factor for problematic weaning from MV. Therefore, developing a clinical intervention to prevent MV-induced diaphragm atrophy is important. In this regard, MV-induced diaphragmatic atrophy occurs due to both increased proteolysis and decreased protein synthesis. While efforts to impede MV-induced increased proteolysis in the diaphragm are well-documented, only one study has investigated methods of preserving diaphragmatic protein synthesis during prolonged MV. Therefore, we evaluated the efficacy of two therapeutic interventions that, conceptually, have the potential to sustain protein synthesis in the rat diaphragm during prolonged MV. Specifically, these experiments were designed to: 1) determine if partial-support MV will protect against the decrease in diaphragmatic protein synthesis that occurs during prolonged full-support MV; and 2) establish if treatment with a mitochondrial-targeted antioxidant will maintain diaphragm protein synthesis during full-support MV. Compared to spontaneously breathing animals, full support MV resulted in a significant decline in diaphragmatic protein synthesis during 12 hours of MV. In contrast, diaphragm protein synthesis rates were maintained during partial support MV at levels comparable to spontaneous breathing animals. Further, treatment of animals with a mitochondrial-targeted antioxidant prevented oxidative stress during full support MV and maintained diaphragm protein synthesis at the level of spontaneous breathing animals. We conclude that treatment with mitochondrial-targeted antioxidants or the use of partial-support MV are potential strategies to preserve diaphragm protein synthesis during prolonged MV.
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94
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Kwon OS, Smuder AJ, Wiggs MP, Hall SE, Sollanek KJ, Morton AB, Talbert EE, Toklu HZ, Tumer N, Powers SK. AT1 receptor blocker losartan protects against mechanical ventilation-induced diaphragmatic dysfunction. J Appl Physiol (1985) 2015; 119:1033-41. [PMID: 26359481 DOI: 10.1152/japplphysiol.00237.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/04/2015] [Indexed: 11/22/2022] Open
Abstract
Mechanical ventilation is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged ventilator support results in diaphragmatic atrophy and contractile dysfunction leading to diaphragm weakness, which is predicted to contribute to problems in weaning patients from the ventilator. While it is established that ventilator-induced oxidative stress is required for the development of ventilator-induced diaphragm weakness, the signaling pathway(s) that trigger oxidant production remain unknown. However, recent evidence reveals that increased plasma levels of angiotensin II (ANG II) result in oxidative stress and atrophy in limb skeletal muscles. Using a well-established animal model of mechanical ventilation, we tested the hypothesis that increased circulating levels of ANG II are required for both ventilator-induced diaphragmatic oxidative stress and diaphragm weakness. Cause and effect was determined by administering an angiotensin-converting enzyme inhibitor (enalapril) to prevent ventilator-induced increases in plasma ANG II levels, and the ANG II type 1 receptor antagonist (losartan) was provided to prevent the activation of ANG II type 1 receptors. Enalapril prevented the increase in plasma ANG II levels but did not protect against ventilator-induced diaphragmatic oxidative stress or diaphragm weakness. In contrast, losartan attenuated both ventilator-induced oxidative stress and diaphragm weakness. These findings indicate that circulating ANG II is not essential for the development of ventilator-induced diaphragm weakness but that activation of ANG II type 1 receptors appears to be a requirement for ventilator-induced diaphragm weakness. Importantly, these experiments provide the first evidence that the Food and Drug Administration-approved drug losartan may have clinical benefits to protect against ventilator-induced diaphragm weakness in humans.
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Affiliation(s)
- Oh Sung Kwon
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Ashley J Smuder
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Michael P Wiggs
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Stephanie E Hall
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Kurt J Sollanek
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Aaron B Morton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Erin E Talbert
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Hale Z Toklu
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida; and Geriatric Research, Education, and Clinical Center, North Florida/South Georgia Veterans Health System, Gainesville, Florida
| | - Nihal Tumer
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida; and Geriatric Research, Education, and Clinical Center, North Florida/South Georgia Veterans Health System, Gainesville, Florida
| | - Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida;
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95
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Abstract
Purpose of review The present review summarizes developments in the field of respiratory muscle monitoring, in particular in critically ill patients. Recent findings Patients admitted to the ICU may develop severe respiratory muscle dysfunction in a very short time span. Among other factors, disuse and sepsis have been associated with respiratory muscle dysfunction in these patients. Because weakness is associated with adverse outcome, including prolonged mechanical ventilation and mortality, it is surprising that respiratory muscle dysfunction largely develops without being noticed by the clinician. Respiratory muscle monitoring is not standard of care in most ICUs. Improvements in technology have opened windows for monitoring the respiratory muscles in critically ill patients. Diaphragm electromyography and esophageal pressure measurement are feasible techniques for respiratory muscle monitoring, although the effect on outcome remains to be investigated. Summary Respiratory muscle dysfunction develops rapidly in selected critically ill patients and is associated with adverse outcome. Recent technological advances allow real-time monitoring of respiratory muscle activity in these patients. Although this field is in its infancy, from a physiological perspective, it is reasonable to assume that monitoring respiratory muscle activity improves outcome in these patients.
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Lago AF, Goncalves EC, Silva EC, Menegueti MG, Nicolini EA, Auxiliadora-Martins M, Martinez EZ, Gastaldi AC, Basile-Filho A. Comparison of Energy Expenditure and Oxygen Consumption of Spontaneous Breathing Trial Conducted With and Without Automatic Tube Compensation. J Clin Med Res 2015; 7:700-5. [PMID: 26251685 PMCID: PMC4522988 DOI: 10.14740/jocmr2250w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2015] [Indexed: 11/13/2022] Open
Abstract
Background Weaning from mechanical ventilation is defined as the process of release of ventilatory support and how the evaluation of this phase is conducted in the spontaneous breathing trial (SBT). One of the most used modes of SBT is the continuous positive airway pressure (CPAP), which applies a continuous positive pressure in both inspiration and expiration. However, together with the mechanical ventilation modes, the automatic tube compensation (ATC) can be used, which compensates the resistance imposed by the endotracheal tube. The objective of this study was to compare oxygen consumption (VO2) and energy expenditure (EE) during SBT conducted with and without ATC. Methods The study was prospective, randomized and crossover. Forty mechanically ventilated patients were admitted to an intensive care unit of a university tertiary hospital. The participants were randomly allocated in group 1, in which SBT was initiated with CPAP and ATC, followed by CPAP without ATC or in group 2, in which SBT was initiated with CPAP without ATC, followed by CPAP with ATC. Indirect calorimetry helped to measure VO2 and EE during SBT. Results The differences between VO2 and EE obtained during SBT with ATC and without ATC were -1.6 mL/kg/min (95% CI: -4.36 - 1.07) and 5.4 kcal/day (95% CI: -21.67 - 10.79), respectively. Conclusions We concluded that VO2 and EE obtained during SBT with and without ATC were not different.
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Affiliation(s)
- Alessandra Fabiane Lago
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Elaine Cristina Goncalves
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Elaine Caetano Silva
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Mayra Goncalves Menegueti
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Edson Antonio Nicolini
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Maria Auxiliadora-Martins
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Edson Zangiacomi Martinez
- Department of Social Medicine, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Ada Clarice Gastaldi
- Department of Physiotherapy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
| | - Anibal Basile-Filho
- Division of Intensive Care, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, SP 14049-900 Ribeirao Preto, Brazil
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97
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Abstract
BACKGROUND Mechanical ventilation (MV) is associated with atrophy and weakness of the diaphragm muscle, a condition termed ventilator-induced diaphragmatic dysfunction (VIDD). Autophagy is a lysosomally mediated proteolytic process that can be activated by oxidative stress, which has the potential to either mitigate or exacerbate VIDD. The primary goals of this study were to (1) determine the effects of MV on autophagy in the diaphragm and (2) evaluate the impact of antioxidant therapy on autophagy induction and MV-induced diaphragmatic weakness. METHODS Mice were assigned to control (CTRL), MV (for 6 h), MV + N-acetylcysteine, MV + rapamycin, and prolonged (48 h) fasting groups. Autophagy was monitored by quantifying (1) autophagic vesicles by transmission electron microscopy, (2) messenger RNA levels of autophagy-related genes, and (3) the autophagosome marker protein LC3B-II, with and without administration of colchicine to calculate the indices of relative autophagosome formation and degradation. Force production by mouse diaphragms was determined ex vivo. RESULTS Diaphragms exhibited a 2.2-fold (95% CI, 1.8 to 2.5) increase in autophagic vesicles visualized by transmission electron microscopy relative to CTRL after 6 h of MV (n = 5 per group). The autophagosome formation index increased in the diaphragm alone (1.5-fold; 95% CI, 1.3 to 1.8; n = 8 per group) during MV, whereas prolonged fasting induced autophagosome formation in both the diaphragm (2.5-fold; 95% CI, 2.2 to 2.8) and the limb muscle (4.1-fold; 95% CI, 1.8 to 6.5). The antioxidant N-acetylcysteine further augmented the autophagosome formation in the diaphragm during MV (1.4-fold; 95% CI, 1.2 to 1.5; n = 8 per group) and prevented MV-induced diaphragmatic weakness. Treatment with the autophagy-inducing agent rapamycin also largely prevented the diaphragmatic force loss associated with MV (n = 6 per group). CONCLUSIONS In this model of VIDD, autophagy is induced by MV but is not responsible for diaphragmatic weakness. The authors propose that autophagy may instead be a beneficial adaptive response that can potentially be exploited for therapy of VIDD.
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Abstract
A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research and development.
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99
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Abstract
PURPOSE OF REVIEW Survivors of a critical illness may experience poor physical function and quality of life as a result of reduced skeletal muscle mass and strength during their acute illness. Patients diagnosed with sepsis are particularly at risk, and mechanical ventilation may result in diaphragm dysfunction. Interest in the interaction of these conditions is both growing and important to understand for individualized patient care. RECENT FINDINGS This review describes developments in the presentation of both diaphragm and limb myopathy in critical illness, as measured from muscle biopsy and at the bedside with various imaging and strength-testing modalities. The influence of unloading of the diaphragm with mechanical ventilation and peripheral muscles with immobilization in septic patients has been recently questioned. Systemic inflammation appears to primarily accelerate and accentuate dysfunction, which may be remedied by early mobilization and augmented with developing muscle and/or nerve stimulation techniques. SUMMARY Many acute muscle changes in septic patients are likely to stem from pre-existing impairments, which should provide context for clinical evaluations of strength. During illness, sarcolemmal injury promotes a cascade of intra-cellular abnormalities. As unique characteristics of ICU-acquired weakness and differential effects on muscle groups are understood, early diagnosis and management should be facilitated.
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Affiliation(s)
- Claire E Baldwin
- aInternational Centre for Allied Health Evidence and School of Health Sciences, University of South Australia, Adelaide bPhysiotherapy Department, Flinders Medical Centre, Bedford Park cDepartment of Critical Care Medicine, School of Medicine, Faculty of Health Sciences, Flinders University, Bedford Park dIntensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, South Australia, Australia
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Jung B, Gleeton D, Daurat A, Conseil M, Mahul M, Rao G, Matecki S, Lacampagne A, Jaber S. Conséquences de la ventilation mécanique sur le diaphragme. Rev Mal Respir 2015; 32:370-80. [DOI: 10.1016/j.rmr.2014.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 08/25/2014] [Indexed: 01/23/2023]
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