1
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Qian X, Jiang Y, Jia J, Shen W, Ding Y, He Y, Xu P, Pan Q, Xu Y, Ge H. PEEP application during mechanical ventilation contributes to fibrosis in the diaphragm. Respir Res 2023; 24:46. [PMID: 36782202 PMCID: PMC9926671 DOI: 10.1186/s12931-023-02356-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Positive end-expiratory airway pressure (PEEP) is a potent component of management for patients receiving mechanical ventilation (MV). However, PEEP may cause the development of diaphragm remodeling, making it difficult for patients to be weaned from MV. The current study aimed to explore the role of PEEP in VIDD. METHODS Eighteen adult male New Zealand rabbits were divided into three groups at random: nonventilated animals (the CON group), animals with volume-assist/control mode without/ with PEEP 8 cmH2O (the MV group/ the MV + PEEP group) for 48 h with mechanical ventilation. Ventilator parameters and diaphragm were collected during the experiment for further analysis. RESULTS There was no difference among the three groups in arterial blood gas and the diaphragmatic excursion during the experiment. The tidal volume, respiratory rate and minute ventilation were similar in MV + PEEP group and MV group. Airway peak pressure in MV + PEEP group was significantly higher than that in MV group (p < 0.001), and mechanical power was significantly higher (p < 0.001). RNA-seq showed that genes associated with fibrosis were enriched in the MV + PEEP group. This results were further confirmed on mRNA expression. As shown by Masson's trichrome staining, there was more collagen fiber in the MV + PEEP group than that in the MV group (p = 0.001). Sirius red staining showed more positive staining of total collagen fibers and type I/III fibers in the MV + PEEP group (p = 0.001; p = 0.001). The western blot results also showed upregulation of collagen types 1A1, III, 6A1 and 6A2 in the MV + PEEP group compared to the MV group (p < 0.001, all). Moreover, the positive immunofluorescence of COL III in the MV + PEEP group was more intense (p = 0.003). Furthermore, the expression of TGF-β1, one of the most potent fibrogenic factors, was upregulated at both the mRNA and protein levels in the MV + PEEP group (mRNA: p = 0.03; protein: p = 0.04). CONCLUSIONS We demonstrated that PEEP application for 48 h in mechanically ventilated rabbits will cause collagen deposition and fibrosis in the diaphragm. Moreover, activation of the TGF-β1 signaling pathway and myofibroblast differentiation may be the potential mechanism of this diaphragmatic fibrosis. These findings might provide novel therapeutic targets for PEEP application-induced diaphragm dysfunction.
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Affiliation(s)
- Xiaoli Qian
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Ye Jiang
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Jianwei Jia
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Weimin Shen
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Yuejia Ding
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Yuhan He
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Peifeng Xu
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016 China
| | - Qing Pan
- grid.469325.f0000 0004 1761 325XCollege of Information Engineering, Zhejiang University of Technology, Liuhe Rd. 288, Hangzhou, 310023 China
| | - Ying Xu
- Department of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016, China.
| | - Huiqing Ge
- Department of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou, 310016, China.
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2
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Miller AG, Tan HL, Smith BJ, Rotta AT, Lee JH. The Physiological Basis of High-Frequency Oscillatory Ventilation and Current Evidence in Adults and Children: A Narrative Review. Front Physiol 2022; 13:813478. [PMID: 35557962 PMCID: PMC9087180 DOI: 10.3389/fphys.2022.813478] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 04/08/2022] [Indexed: 12/12/2022] Open
Abstract
High-frequency oscillatory ventilation (HFOV) is a type of invasive mechanical ventilation that employs supra-physiologic respiratory rates and low tidal volumes (VT) that approximate the anatomic deadspace. During HFOV, mean airway pressure is set and gas is then displaced towards and away from the patient through a piston. Carbon dioxide (CO2) is cleared based on the power (amplitude) setting and frequency, with lower frequencies resulting in higher VT and CO2 clearance. Airway pressure amplitude is significantly attenuated throughout the respiratory system and mechanical strain and stress on the alveoli are theoretically minimized. HFOV has been purported as a form of lung protective ventilation that minimizes volutrauma, atelectrauma, and biotrauma. Following two large randomized controlled trials showing no benefit and harm, respectively, HFOV has largely been abandoned in adults with ARDS. A multi-center clinical trial in children is ongoing. This article aims to review the physiologic rationale for the use of HFOV in patients with acute respiratory failure, summarize relevant bench and animal models, and discuss the potential use of HFOV as a primary and rescue mode in adults and children with severe respiratory failure.
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Affiliation(s)
- Andrew G Miller
- Duke University Medical Center, Respiratory Care Services, Durham, NC, United States
| | - Herng Lee Tan
- KK Women's and Children's Hospital, Children's Intensive Care Unit, Singapore, Singapore
| | - Brian J Smith
- University of California, Davis, Respiratory Care Services, Sacramento, CA, United States
| | - Alexandre T Rotta
- Duke University Medical Center, Division of Pediatric Critical Care Medicine, Durham, NC, United States
| | - Jan Hau Lee
- KK Women's and Children's Hospital, Children's Intensive Care Unit, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
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3
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DNA damage assessment in pneumonia patients treated in the intensive care unit. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01050-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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4
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Triantaris A, Aidonidis I, Hatziefthimiou A, Gourgoulianis K, Zakynthinos G, Makris D. Elevated PaCO 2 levels increase pulmonary artery pressure. Sci Prog 2022; 105:368504221094161. [PMID: 35440248 PMCID: PMC10358613 DOI: 10.1177/00368504221094161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Permissive hypercapnia is commonly used in mechanically ventilated patients to avoid lung injury but its effect on pulmonary artery pressure (PAP) is still unclear, particularly in combination with tidal volume (Vt). Therefore, an in vivo study was performed on adult rabbits ventilated with low (9 ml/Kg, LVt group) or high (15 ml/Kg, HVt group) tidal volume (Vt) and alterations in PAP were estimated. Both groups of animals initially were ventilated with FiO2 0.3 (Normocapnia-1) followed by inhalation of enriched CO2 gas mixture (FiCO2 0.10) to develop hypercapnia (Hypercapnia-1). After 30 min of hypercapnia, animals were re-ventilated with FiO2 0.3 to develop normocapnia (Normocapnia-2) again and then with FiCO2 0.10 to develop hypercapnia (Hypercapnia-2). Systolic, diastolic and mean PAP were assessed with a catheter in the pulmonary artery. In HP-1 and HP-2, PaCO2 increased (p < 0.0001) in both LVt and HVt animals compared to baseline values. pH decreased to ≈7.2 in HP-1 and ≈7.1 in HP -2. In normocapnia, the rise in Vt from 9 to 15 ml/Kg induced an increase in static compliance (Cstat), plateau airway pressure (Pplat) and PAP. Hypercapnia increased PAP in either LVt or HVt animals without significant effect on Cstat or Pplat. A two-way ANOVA revealed that there was not a statistically significant interaction between the effects of hypercapnia and tidal volume on mPAP (p = 0.76). In conclusion, increased Vt per se induced an increase in Cstat, Pplat and PAP in normocapnia. Hypercapnia increased PAP in rabbits ventilated with low or high Vt but this effect was not long-lasting.
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Affiliation(s)
- Apostolos Triantaris
- Intensive Care Unit, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Isaak Aidonidis
- Laboratory of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Apostolia Hatziefthimiou
- Laboratory of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Konstantinos Gourgoulianis
- Department of Respiratory Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Georgios Zakynthinos
- Intensive Care Unit, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Demosthenes Makris
- Intensive Care Unit, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
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5
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Miller AG, Bartle RM, Feldman A, Mallory P, Reyes E, Scott B, Rotta AT. A narrative review of advanced ventilator modes in the pediatric intensive care unit. Transl Pediatr 2021; 10:2700-2719. [PMID: 34765495 PMCID: PMC8578787 DOI: 10.21037/tp-20-332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/26/2020] [Indexed: 01/29/2023] Open
Abstract
Respiratory failure is a common reason for pediatric intensive care unit admission. The vast majority of children requiring mechanical ventilation can be supported with conventional mechanical ventilation (CMV) but certain cases with refractory hypoxemia or hypercapnia may require more advanced modes of ventilation. This paper discusses what we have learned about the use of advanced ventilator modes [e.g., high-frequency oscillatory ventilation (HFOV), high-frequency percussive ventilation (HFPV), high-frequency jet ventilation (HFJV) airway pressure release ventilation (APRV), and neurally adjusted ventilatory assist (NAVA)] from clinical, animal, and bench studies. The evidence supporting advanced ventilator modes is weak and consists of largely of single center case series, although a few RCTs have been performed. Animal and bench models illustrate the complexities of different modes and the challenges of applying these clinically. Some modes are proprietary to certain ventilators, are expensive, or may only be available at well-resourced centers. Future efforts should include large, multicenter observational, interventional, or adaptive design trials of different rescue modes (e.g., PROSpect trial), evaluate their use during ECMO, and should incorporate assessments through volumetric capnography, electric impedance tomography, and transpulmonary pressure measurements, along with precise reporting of ventilator parameters and physiologic variables.
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Affiliation(s)
- Andrew G Miller
- Duke University Medical Center, Durham, NC, USA.,Respiratory Care Services, Duke University Medical Center, Durham, NC, USA
| | - Renee M Bartle
- Duke University Medical Center, Durham, NC, USA.,Respiratory Care Services, Duke University Medical Center, Durham, NC, USA
| | - Alexandra Feldman
- Duke University Medical Center, Durham, NC, USA.,Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Palen Mallory
- Duke University Medical Center, Durham, NC, USA.,Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Edith Reyes
- Duke University Medical Center, Durham, NC, USA.,Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Briana Scott
- Duke University Medical Center, Durham, NC, USA.,Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Alexandre T Rotta
- Duke University Medical Center, Durham, NC, USA.,Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
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6
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Rotta AT, Martinez Herrada AJ, Zee-Cheng JE, Shein SL. Refractory Atelectasis and Response to Chest Physiotherapy. J Pediatr Intensive Care 2021; 12:156-157. [PMID: 37082467 PMCID: PMC10113012 DOI: 10.1055/s-0041-1728640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Alexandre T. Rotta
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States
| | - Alejandro J. Martinez Herrada
- Division of Pediatrics Critical Care Medicine, Department of Pediatrics, Rainbow Babies & Children's Hospital, Cleveland, Ohio, United States
| | - Janine E. Zee-Cheng
- Division of Hospital Medicine, Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana, United States
| | - Steven L. Shein
- Division of Pediatrics Critical Care Medicine, Department of Pediatrics, Rainbow Babies & Children's Hospital, Cleveland, Ohio, United States
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7
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Experimental Models of Acute Lung Injury: their Advantages and Limitations. ACTA MEDICA MARTINIANA 2020. [DOI: 10.2478/acm-2020-0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Acute damage to the lung may originate from various direct and indirect reasons. Direct lung injury may be caused by pneumonia, near-drowning, aspiration, inhalation of toxic gases etc., while indirect lung injury is secondary, following any severe extra-pulmonary disease, e.g. sepsis, acute pancreatitis, or severe trauma. Due to a complex pathophysiology of the acute lung injury, the treatment is also extremely complicated and except for lung-protective ventilation there have been no specific treatment approaches recommended. An urgent need for a reliable and sufficiently effective treatment forces the researchers into testing novel therapeutic strategies. However, most of these determinations should be done in the laboratory conditions using animals. Complex methods of preparation of various experimental models of the acute lung injury has gradually developed within decades. Nowadays, there have been the models of direct, indirect, or mixed lung injury well established, as well as the models evoked by a combination of two triggering factors. Although the applicability of the results from animal experiments to patients might be limited by many factors, animal models are essential for understanding the patho-physiology of acute lung injury and provide an exceptional opportunity to search for novel therapeutical strategies.
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8
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Zhou XL, Wei XJ, Li SP, Ma HL, Zhao Y. Lung-protective ventilation worsens ventilator-induced diaphragm atrophy and weakness. Respir Res 2020; 21:16. [PMID: 31924204 PMCID: PMC6954632 DOI: 10.1186/s12931-020-1276-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/02/2020] [Indexed: 02/07/2023] Open
Abstract
Background Lung–protective ventilation (LPV) has been found to minimize the risk of ventilator–induced lung injury (VILI). However, whether LPV is able to diminish ventilator–induced diaphragm dysfunction (VIDD) remains unknown. This study was designed to test the hypothesis that LPV protects the diaphragm against VIDD. Methods Adult male Wistar rats received either conventional mechanical (tidal volume [VT]: 10 ml/kg, positive end–expiratory pressure [PEEP]: 2 cm H2O; CV group) or lung-protective (VT: 5 ml/kg, PEEP: 10 cm H2O; LPV group) ventilation for 12 h. Then, diaphragms and lungs were collected for biochemical and histological analyses. Transcriptome sequencing (RNA–seq) was performed to determine the differentially expressed genes in the diaphragms between groups. Results Our results suggested that LPV was associated with diminished pulmonary injuries and reduced oxidative stress compared with the effects of the CV strategy in rats. However, animals that received LPV showed increased protein degradation, decreased cross–sectional areas (CSAs) of myofibers, and reduced forces of the diaphragm compared with the same parameters in animals receiving CV (p < 0.05). In addition, the LPV group showed a higher level of oxidative stress in the diaphragm than the CV group (p < 0.05). Moreover, RNA–seq and western blots revealed that the peroxisome proliferator–activated receptor γ coactivator–1alpha (PGC–1α), a powerful reactive oxygen species (ROS) inhibitor, was significantly downregulated in the LPV group compared with its expression in the CV group (p < 0.05). Conclusions Compared with the CV strategy, the LPV strategy did not protect the diaphragm against VIDD in rats. In contrast, the LPV strategy worsened VIDD by inducing oxidative stress together with the downregulation of PGC–1α in the diaphragm. However, further studies are required to determine the roles of PGC–1α in ventilator-induced diaphragmatic oxidative stress.
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Affiliation(s)
- Xian-Long Zhou
- Emergency Center, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China
| | - Xiao-Jun Wei
- Emergency Center, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China
| | - Shao-Ping Li
- Emergency Center, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China
| | - Hao-Li Ma
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China
| | - Yan Zhao
- Emergency Center, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China.
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9
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Nof E, Heller-Algazi M, Coletti F, Waisman D, Sznitman J. Ventilation-induced jet suggests biotrauma in reconstructed airways of the intubated neonate. J R Soc Interface 2020; 17:20190516. [PMID: 31910775 PMCID: PMC7014802 DOI: 10.1098/rsif.2019.0516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We investigate respiratory flow phenomena in a reconstructed upper airway model of an intubated neonate undergoing invasive mechanical ventilation, spanning conventional to high-frequency ventilation (HFV) modes. Using high-speed tomographic particle image velocimetry, we resolve transient, three-dimensional flow fields and observe a persistent jet flow exiting the endotracheal tube whose strength is directly modulated according to the ventilation protocol. We identify this synthetic jet as the dominating signature of convective flow under intubated ventilation. Concurrently, our in silico wall shear stress analysis reveals a hitherto overlooked source of ventilator-induced lung injury as a result of jet impingement on the tracheal carina, suggesting damage to the bronchial epithelium; this type of injury is known as biotrauma. We find HFV advantageous in mitigating the intensity of such impingement, which may contribute to its role as a lung protective method. Our findings may encourage the adoption of less invasive ventilation procedures currently used in neonatal intensive care units.
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Affiliation(s)
- Eliram Nof
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Metar Heller-Algazi
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Filippo Coletti
- Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Dan Waisman
- Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel.,Department of Neonatology, Carmel Medical Center, Haifa 3436212, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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10
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What Is Weighing Us Down From Elucidating Ideal Ventilation Strategies in Pediatric Acute Respiratory Distress Syndrome? Pediatr Crit Care Med 2019; 20:303-305. [PMID: 30830026 DOI: 10.1097/pcc.0000000000001857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Voelker MT, Bergmann A, Busch T, Jahn N, Laudi S, Noreikat K, Simon P, Bercker S. The effects of hemoglobin glutamer-200 and iNO on pulmonary vascular tone and arterial oxygenation in an experimental acute respiratory distress syndrome. Pulm Pharmacol Ther 2018; 49:130-133. [DOI: 10.1016/j.pupt.2018.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 12/16/2017] [Accepted: 01/25/2018] [Indexed: 11/17/2022]
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12
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Abstract
Acute lung injury in the preterm newborns can originate from prematurity of the lung and insufficient synthesis of pulmonary surfactant. This situation is known as respiratory distress syndrome (RDS). In the term neonates, the respiratory insufficiency is related to a secondary inactivation of the pulmonary surfactant, for instance, by action of endotoxins in bacterial pneumonia or by effects of aspirated meconium. The use of experimental models of the mentioned situations provides new information on the pathophysiology of these disorders and offers unique possibility to test novel therapeutic approaches in the conditions which are very similar to the clinical syndromes. Herewith we review the advantages and limitations of the use of experimental models of RDS and meconium aspiration syndrome (MAS) and their value for clinics.
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Affiliation(s)
- D. MOKRA
- Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
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13
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Retamal J, Borges JB, Bruhn A, Cao X, Feinstein R, Hedenstierna G, Johansson S, Suarez-Sipmann F, Larsson A. High respiratory rate is associated with early reduction of lung edema clearance in an experimental model of ARDS. Acta Anaesthesiol Scand 2016; 60:79-92. [PMID: 26256848 DOI: 10.1111/aas.12596] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/08/2015] [Accepted: 07/13/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND The independent impact of respiratory rate on ventilator-induced lung injury has not been fully elucidated. The aim of this study was to investigate the effects of two clinically relevant respiratory rates on early ventilator-induced lung injury evolution and lung edema during the protective ARDSNet strategy. We hypothesized that the use of a higher respiratory rate during a protective ARDSNet ventilation strategy increases lung inflammation and, in addition, lung edema associated to strain-induced activation of transforming growth factor beta (TGF-β) in the lung epithelium. METHODS Twelve healthy piglets were submitted to a two-hit lung injury model and randomized into two groups: LRR (20 breaths/min) and HRR (40 breaths/min). They were mechanically ventilated during 6 h according to the ARDSNet strategy. We assessed respiratory mechanics, hemodynamics, and extravascular lung water (EVLW). At the end of the experiment, the lungs were excised and wet/dry ratio, TGF-β pathway markers, regional histology, and cytokines were evaluated. RESULTS No differences in oxygenation, PaCO2 levels, systemic and pulmonary arterial pressures were observed during the study. Respiratory system compliance and mean airway pressure were lower in LRR group. A decrease in EVLW over time occurred only in the LRR group (P < 0.05). Wet/dry ratio was higher in the HRR group (P < 0.05), as well as TGF-β pathway activation. Histological findings suggestive of inflammation and inflammatory tissue cytokines were higher in LRR. CONCLUSION HRR was associated with more pulmonary edema and higher activation of the TGF-β pathway. In contrast with our hypothesis, HRR was associated with less lung inflammation.
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Affiliation(s)
- J. Retamal
- Hedenstierna Laboratory; Department of Surgical Sciences; Section of Anaesthesiology & Critical Care; Uppsala University; Uppsala Sweden
- Departamento de Medicina Intensiva; Pontificia Universidad Cat ó lica de Chile; Santiago Chile
| | - J. B. Borges
- Hedenstierna Laboratory; Department of Surgical Sciences; Section of Anaesthesiology & Critical Care; Uppsala University; Uppsala Sweden
- Cardio-Pulmonary Department; Pulmonary Divison; Heart Institute (Incor); University of São Paulo; São Paulo Brazil
| | - A. Bruhn
- Departamento de Medicina Intensiva; Pontificia Universidad Cat ó lica de Chile; Santiago Chile
| | - X. Cao
- Department of Medical Biochemistry and Microbiology; Uppsala University; Uppsala Sweden
| | - R. Feinstein
- Department of Pathology and Wildlife Diseases; National Veterinary Institute; Uppsala Sweden
| | - G. Hedenstierna
- Department of Medical Science, Clinical Physiology; Uppsala University Hospital; Uppsala Sweden
| | - S. Johansson
- Department of Medical Biochemistry and Microbiology; Uppsala University; Uppsala Sweden
| | - F. Suarez-Sipmann
- Hedenstierna Laboratory; Department of Surgical Sciences; Section of Anaesthesiology & Critical Care; Uppsala University; Uppsala Sweden
| | - A. Larsson
- Hedenstierna Laboratory; Department of Surgical Sciences; Section of Anaesthesiology & Critical Care; Uppsala University; Uppsala Sweden
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14
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Hupp SR, Turner DA, Rehder KJ. Is there still a role for high-frequency oscillatory ventilation in neonates, children and adults? Expert Rev Respir Med 2015; 9:603-18. [PMID: 26290121 DOI: 10.1586/17476348.2015.1077119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Critically ill patients with respiratory pathology often require mechanical ventilation and while low tidal volume ventilation has become the mainstay of treatment, achieving adequate gas exchange may not be attainable with conventional ventilator modalities. In attempt to achieve gas exchange goals and also mitigate lung injury, high frequency ventilation is often implemented which couples low tidal volumes with sustained mean airway pressure. This manuscript presents the physiology of high-frequency oscillatory ventilation, reviews the currently available data on its use and provides strategies and approaches for this mode of ventilation.
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Affiliation(s)
| | - David A Turner
- a Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kyle J Rehder
- a Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
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15
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Castillo RL, Carrasco Loza R, Romero-Dapueto C. Pathophysiological Approaches of Acute Respiratory Distress syndrome: Novel Bases for Study of Lung Injury. Open Respir Med J 2015; 9:83-91. [PMID: 26312099 PMCID: PMC4541465 DOI: 10.2174/1874306401509010083] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 04/16/2015] [Accepted: 04/16/2015] [Indexed: 12/22/2022] Open
Abstract
Experimental approaches have been implemented to research the lung damage related-mechanism. These models show in animals pathophysiological events for acute respiratory distress syndrome (ARDS), such as neutrophil activation, reactive oxygen species burst, pulmonary vascular hypertension, exudative edema, and other events associated with organ dysfunction. Moreover, these approaches have not reproduced the clinical features of lung damage. Lung inflammation is a relevant event in the develop of ARDS as component of the host immune response to various stimuli, such as cytokines, antigens and endotoxins. In patients surviving at the local inflammatory states, transition from injury to resolution is an active mechanism regulated by the immuno-inflammatory signaling pathways. Indeed, inflammatory process is regulated by the dynamics of cell populations that migrate to the lung, such as neutrophils and on the other hand, the role of the modulation of transcription factors and reactive oxygen species (ROS) sources, such as nuclear factor kappaB and NADPH oxidase. These experimental animal models reproduce key components of the injury and resolution phases of human ALI/ARDS and provide a methodology to explore mechanisms and potential new therapies.
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Affiliation(s)
- R L Castillo
- Programa de Fisiopatología, Facultad de Medicina, Universidad de Chile, Chile
| | - R Carrasco Loza
- Departamento de Medicina, Hospital del Salvador, Santiago, Chile; Laboratorio de Investigación Biomédica, Hospital del Salvador, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - C Romero-Dapueto
- Servicio de Medicina Física y Rehabilitación, Clínica Alemana de Santiago, Santiago, Chile
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Guo R, Fan E. Beyond low tidal volumes: ventilating the patient with acute respiratory distress syndrome. Clin Chest Med 2014; 35:729-41. [PMID: 25453421 DOI: 10.1016/j.ccm.2014.08.010] [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] [Indexed: 11/30/2022]
Abstract
The cornerstone of lung protective ventilation in patients with acute respiratory distress syndrome (ARDS) is a pressure- and volume-limited strategy. Other interventions have also been investigated. Although no method for positive end-expiratory pressure (PEEP) titration has proven most advantageous, experimental and clinical data support the use of higher PEEP in patients with moderate/severe ARDS. There is no benefit to the early use of high-frequency oscillatory ventilation (HFOV) in patients with moderate/severe ARDS, although it may be considered as rescue therapy. Further investigations of novel methods of bedside monitoring of mechanical ventilation may help identify the optimal ventilatory strategy.
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Affiliation(s)
- Ray Guo
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Eddy Fan
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.
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Retamal J, Bergamini BC, Carvalho AR, Bozza FA, Borzone G, Borges JB, Larsson A, Hedenstierna G, Bugedo G, Bruhn A. Non-lobar atelectasis generates inflammation and structural alveolar injury in the surrounding healthy tissue during mechanical ventilation. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:505. [PMID: 25200702 PMCID: PMC4172813 DOI: 10.1186/s13054-014-0505-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 08/22/2014] [Indexed: 12/16/2022]
Abstract
Introduction When alveoli collapse the traction forces exerted on their walls by adjacent expanded units may increase and concentrate. These forces may promote its re-expansion at the expense of potentially injurious stresses at the interface between the collapsed and the expanded units. We developed an experimental model to test the hypothesis that a local non-lobar atelectasis can act as a stress concentrator, contributing to inflammation and structural alveolar injury in the surrounding healthy lung tissue during mechanical ventilation. Methods A total of 35 rats were anesthetized, paralyzed and mechanically ventilated. Atelectasis was induced by bronchial blocking: after five minutes of stabilization and pre-oxygenation with FIO2 = 1.0, a silicon cylinder blocker was wedged in the terminal bronchial tree. Afterwards, the animals were randomized between two groups: 1) Tidal volume (VT) = 10 ml/kg and positive end-expiratory pressure (PEEP) = 3 cmH2O (VT10/PEEP3); and 2) VT = 20 ml/kg and PEEP = 0 cmH2O (VT20/zero end-expiratory pressure (ZEEP)). The animals were then ventilated during 180 minutes. Three series of experiments were performed: histological (n = 12); tissue cytokines (n = 12); and micro-computed tomography (microCT; n = 2). An additional six, non-ventilated, healthy animals were used as controls. Results Atelectasis was successfully induced in the basal region of the lung of 26 out of 29 animals. The microCT of two animals revealed that the volume of the atelectasis was 0.12 and 0.21 cm3. There were more alveolar disruption and neutrophilic infiltration in the peri-atelectasis region than the corresponding contralateral lung (control) in both groups. Edema was higher in the peri-atelectasis region than the corresponding contralateral lung (control) in the VT20/ZEEP than VT10/PEEP3 group. The volume-to-surface ratio was higher in the peri-atelectasis region than the corresponding contralateral lung (control) in both groups. We did not find statistical difference in tissue interleukin-1β and cytokine-induced neutrophil chemoattractant-1 between regions. Conclusions The present findings suggest that a local non-lobar atelectasis acts as a stress concentrator, generating structural alveolar injury and inflammation in the surrounding lung tissue.
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Early inflammation mainly affects normally and poorly aerated lung in experimental ventilator-induced lung injury*. Crit Care Med 2014; 42:e279-87. [PMID: 24448197 DOI: 10.1097/ccm.0000000000000161] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE The common denominator in most forms of ventilator-induced lung injury is an intense inflammatory response mediated by neutrophils. PET with [(18)F]fluoro-2-deoxy-D-glucose can be used to image cellular metabolism, which, during lung inflammatory processes, mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. The aim of this study was to assess the location and magnitude of lung inflammation using PET imaging of [(18)F]fluoro-2-deoxy-D-glucose in a porcine experimental model of early acute respiratory distress syndrome. DESIGN Prospective laboratory investigation. SETTING A university animal research laboratory. SUBJECTS Seven piglets submitted to experimental ventilator-induced lung injury and five healthy controls. INTERVENTIONS Lung injury was induced by lung lavages and 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressure and high inspiratory pressures. All animals were subsequently studied with dynamic PET imaging of [(18)F]fluoro-2-deoxy-D-glucose. CT scans were acquired at end expiration and end inspiration. MEASUREMENTS AND MAIN RESULTS [(18)F]fluoro-2-deoxy-D-glucose uptake rate was computed for the whole lung, four isogravitational regions, and regions grouping voxels with similar density. Global and intermediate gravitational zones [(18)F]fluoro-2-deoxy-D-glucose uptakes were higher in ventilator-induced lung injury piglets compared with controls animals. Uptake of normally and poorly aerated regions was also higher in ventilator-induced lung injury piglets compared with control piglets, whereas regions suffering tidal recruitment or tidal hyperinflation had [(18)F]fluoro-2-deoxy-D-glucose uptakes similar to controls. CONCLUSIONS The present findings suggest that normally and poorly aerated regions--corresponding to intermediate gravitational zones--are the primary targets of the inflammatory process accompanying early experimental ventilator-induced lung injury. This may be attributed to the small volume of the aerated lung, which receives most of ventilation.
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Henderson WR, Barnbrook J, Dominelli PB, Griesdale DE, Arndt T, Molgat-Seon Y, Foster G, Ackland GL, Xu J, Ayas NT, Sheel AW. Administration of intrapulmonary sodium polyacrylate to induce lung injury for the development of a porcine model of early acute respiratory distress syndrome. Intensive Care Med Exp 2014; 2:5. [PMID: 26266906 PMCID: PMC4513039 DOI: 10.1186/2197-425x-2-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 01/10/2014] [Indexed: 12/15/2022] Open
Abstract
Background The loss of alveolar epithelial and endothelial integrity is a central component in acute respiratory distress syndrome (ARDS); however, experimental models investigating the mechanisms of epithelial injury are lacking. The purpose of the present study was to design and develop an experimental porcine model of ARDS by inducing lung injury with intrapulmonary administration of sodium polyacrylate (SPA). Methods The present study was performed at the Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia. Human alveolar epithelial cells were cultured with several different concentrations of SPA; a bioluminescence technique was used to assess cell death associated with each concentration. In the anesthetized pig model (female Yorkshire X pigs (n = 14)), lung injury was caused in 11 animals (SPA group) by injecting sequential aliquots (5 mL) of 1% SPA gel in aqueous solution into the distal airway via a rubber catheter through an endotracheal tube. The SPA was dispersed throughout the lungs by manual bag ventilation. Three control animals (CON group) underwent all experimental procedures and measurements with the exception of SPA administration. Results The mean (± SD) ATP concentration after incubation of human alveolar epithelial cells with 0.1% SPA (0.92 ± 0.27 μM/well) was approximately 15% of the value found for the background control (6.30 ± 0.37 μM/well; p < 0.001). Elastance of the respiratory system (ERS) and the lung (EL) increased in SPA-treated animals after injury (p = 0.003 and p < 0.001, respectively). Chest wall elastance (ECW) did not change in SPA-treated animals. There were no differences in ERS,EL, or ECW in the CON group when pre- and post-injury values were compared. Analysis of bronchoalveolar lavage fluid showed a significant shift toward neutrophil predominance from before to after injury in SPA-treated animals (p < 0.001) but not in the CON group (p = 0.38). Necropsy revealed marked consolidation and congestion of the dorsal lung lobes in SPA-treated animals, with light-microscopy evidence of bronchiolar and alveolar spaces filled with neutrophilic infiltrate, proteinaceous debris, and fibrin deposition. These findings were absent in animals in the CON group. Electron microscopy of lung tissue from SPA-treated animals revealed injury to the alveolar epithelium and basement membranes, including intra-alveolar neutrophils and fibrin on the alveolar surface and intravascular fibrin (microthrombosis). Conclusions In this particular porcine model, the nonimmunogenic polymer SPA caused a rapid exudative lung injury. This model may be useful to study ARDS caused by epithelial injury and inflammation.
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Affiliation(s)
- William R Henderson
- Wolfson Institute for Biomedical Research, Department of Medicine, University College London, London, WC1E 6BT, UK,
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Ronchi CF, Ferreira ALA, Campos FJ, Kurokawa CS, Carpi MF, Moraes MA, Bonatto RC, Yeum KJ, Fioretto JR. Interactive effects of mechanical ventilation, inhaled nitric oxide and oxidative stress in acute lung injury. Respir Physiol Neurobiol 2014; 190:118-23. [DOI: 10.1016/j.resp.2013.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
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Dechert RE, Haas CF, Ostwani W. Current knowledge of acute lung injury and acute respiratory distress syndrome. Crit Care Nurs Clin North Am 2013; 24:377-401. [PMID: 22920464 DOI: 10.1016/j.ccell.2012.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) continues to be a major cause of mortality in adult and pediatric critical care medicine. This article discusses the pulmonary sequelae associated with ALI and ARDS, the support of ARDS with mechanical ventilation, available adjunctive therapies, and experimental therapies currently being tested. It is hoped that further understanding of the fundamental biology, improved identification of the patient's inflammatory state, and application of therapies directed at multiple sites of action may ultimately prove beneficial for patients suffering from ALI/ARDS.
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Affiliation(s)
- Ronald E Dechert
- Department of Respiratory Care, University of Michigan Health System, 8-720 Mott Hospital, 1540 East Hospital Drive, SPC 4208, Ann Arbor, MI 48109, USA.
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Spontaneous breathing during lung-protective ventilation in an experimental acute lung injury model. Crit Care Med 2012; 40:1578-85. [DOI: 10.1097/ccm.0b013e3182451c40] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Haddad LB, Manzano RM, Rossi FDS, Freddi NA, Prado C, Rebello CM. Improvement in ARDS experimental model installation: low mortality rate and maintenance of hemodynamic stability. J Pharmacol Toxicol Methods 2012; 65:102-6. [PMID: 22440808 DOI: 10.1016/j.vascn.2012.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 02/24/2012] [Accepted: 02/26/2012] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Many experimental models using lung lavage have been developed for the study of acute respiratory distress syndrome (ARDS). The original technique has been modified by many authors, resulting in difficulties with reproducibility. There is insufficient detail on the lung injury models used, including hemodynamic stability during animal preparation and drawbacks encountered such as mortality. The authors studied the effects of the pulmonary recruitment and the use of fixed tidal volume (Vt) or fixed inspiratory pressure in the experimental ARDS model installation. METHODS Adult rabbits were submitted to repeated lung lavages with 30 ml/kg warm saline until the ARDS definition (PaO₂/FiO₂ ≤ 100) was reached. The animals were divided into three groups, according to the technique used for mechanical ventilation: 1) fixed Vt of 10 ml/kg; 2) fixed inspiratory pressure (IP) with a tidal volume of 10 ml/kg prior to the first lung lavage; and 3) fixed Vt of 10 ml/kg with pulmonary recruitment before the first lavage. RESULTS The use of alveolar recruitment maneuvers, and the use of a fixed Vt or IP between the lung lavages did not change the number of lung lavages necessary to obtain the experimental model of ARDS or the hemodynamic stability of the animals during the procedure. A trend was observed toward an increased mortality rate with the recruitment maneuver and with the use of a fixed IP. DISCUSSION There were no differences between the three study groups, with no disadvantage in method of lung recruitment, either fixed tidal volume or fixed inspiratory pressure, regarding the number of lung lavages necessary to obtain the ARDS animal model. Furthermore, the three different procedures resulted in good hemodynamic stability of the animals, and low mortality rate.
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Ronchi CF, Fioretto JR, Ferreira ALA, Berchieri-Ronchi CB, Correa CR, Kurokawa CS, Carpi MF, Moraes MA, Yeum KJ. Biomarkers for oxidative stress in acute lung injury induced in rabbits submitted to different strategies of mechanical ventilation. J Appl Physiol (1985) 2012; 112:1184-90. [PMID: 22302956 DOI: 10.1152/japplphysiol.01334.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Oxidative damage has been said to play an important role in pulmonary injury, which is associated with the development and progression of acute respiratory distress syndrome (ARDS). We aimed to identify biomarkers to determine the oxidative stress in an animal model of acute lung injury (ALI) using two different strategies of mechanical ventilation. Rabbits were ventilated using either conventional mechanical ventilation (CMV) or high-frequency oscillatory ventilation (HFOV). Lung injury was induced by tracheal saline infusion (30 ml/kg, 38°C). In addition, five healthy rabbits were studied for oxidative stress. Isolated lymphocytes from peripheral blood and lung tissue samples were analyzed by alkaline single cell gel electrophoresis (comet assay) to determine DNA damage. Total antioxidant performance (TAP) assay was applied to measure overall antioxidant performance in plasma and lung tissue. HFOV rabbits had similar results to healthy animals, showing significantly higher antioxidant performance and lower DNA damage compared with CMV in lung tissue and plasma. Total antioxidant performance showed a significant positive correlation (r = 0.58; P = 0.0006) in plasma and lung tissue. In addition, comet assay presented a significant positive correlation (r = 0.66; P = 0.007) between cells recovered from target tissue and peripheral blood. Moreover, antioxidant performance was significantly and negatively correlated with DNA damage (r = -0.50; P = 0.002) in lung tissue. This study indicates that both TAP and comet assay identify increased oxidative stress in CMV rabbits compared with HFOV. Antioxidant performance analyzed by TAP and oxidative DNA damage by comet assay, both in plasma, reflects oxidative stress in the target tissue, which warrants further studies in humans.
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Affiliation(s)
- Carlos Fernando Ronchi
- Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
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Abstract
In the last 2 decades, our goals for mechanical ventilatory support in patients with acute respiratory distress syndrome (ARDS) or acute lung injury (ALI) have changed dramatically. Several randomized controlled trials have built on a substantial body of preclinical work to demonstrate that the way in which we employ mechanical ventilation has an impact on important patient outcomes. Avoiding ventilator-induced lung injury (VILI) is now a major focus when clinicians are considering which ventilatory strategy to employ in patients with ALI/ARDS. Physicians are searching for methods that may further limit VILI, while still achieving adequate gas exchange.
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Affiliation(s)
- Sammy Ali
- Internal Medicine Program, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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Ronchi CF, dos Anjos Ferreira AL, Campos FJ, Kurokawa CS, Carpi MF, de Moraes MA, Bonatto RC, Defaveri J, Yeum KJ, Fioretto JR. High-frequency oscillatory ventilation attenuates oxidative lung injury in a rabbit model of acute lung injury. Exp Biol Med (Maywood) 2011; 236:1188-96. [DOI: 10.1258/ebm.2011.011085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mechanical ventilation (MV) can induce lung oxidative stress, which plays an important role in pulmonary injury. This study compared protective conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV) for oxygenation, oxidative stress, inflammatory and histopathological lung injury in a rabbit model of acute lung injury (ALI). Rabbits ( n = 30) were ventilated at FiO2 1.0. Lung injury was induced by tracheal saline infusion (30 mL/kg, 38°C). Animals were randomly assigned to: (a) sham control (CG: tidal volume [ VT] 6 mL/kg, positive end expiratory pressure [PEEP] 5 cmH2O, respiratory rate [RR] 40 ipm); (b) ALI + CMV (CMVG: VT 6 mL/kg, PEEP 10 cmH2O, RR 40 ipm); or (c) ALI + HFOV (HFG: mean airway pressure [Paw] 14 cmH2O, RR 10 Hz) groups. Lung oxidative stress was assessed by total antioxidant performance assay, inflammatory response by the number of polymorphonuclear leukocytes/bronchoalveolar lavage fluid/lung and pulmonary histological damage was quantified by a score. Ventilatory and hemodynamic parameters were recorded every 30 min. Both ALI groups showed worse oxygenation after lung injury induction. After four hours of ventilation, HFG showed better oxygenation (partial pressure of oxygen [PaO2] – CG: 465.9 ± 30.5 = HFG: 399.1 ± 98.2 > CMVG: 232.7 ± 104 mmHg, P < 0.05) and inflammatory responses (CMVG: 4.27 ± 1.50 > HFG: 0.33 ± 0.20 = CG: 0.16 ± 0.15; polymorphonuclear cells/bronchoalveolar lavage fluid/lung, P < 0.05), less histopathological injury score (CMVG: 5 [1–16] > HFG: 1 [0–5] > CG: 0 [0–3]; P < 0.05), and lower lung oxidative stress than CMVG (CG: 59.4 ± 4.52 = HFG: 69.0 ± 4.99 > CMVG: 47.6 ± 2.58% protection/g protein, P < 0.05). This study showed that HFOV had an important protective role in ALI. It improved oxygenation, reduced inflammatory process and histopathological damage, and attenuated oxidative lung injury compared with protective CMV under these experimental conditions considering the study limitations.
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Affiliation(s)
- Carlos Fernando Ronchi
- Internal Medicine Department
- Jean Mayer USDA – Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | | | | | | | | | | | | | - Julio Defaveri
- Pathology Department, Sao Paulo State University (UNESP), Botucatu Medical School, 18618-970 Botucatu, SP, Brazil
| | - Kyung-Jin Yeum
- Jean Mayer USDA – Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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Open the lung with high-frequency oscillation ventilation or conventional mechanical ventilation? It may not matter! CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:1010. [PMID: 21156085 PMCID: PMC3220010 DOI: 10.1186/cc9343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The 'open lung' approach has been proposed as a reasonable ventilation strategy to mitigate ventilator-induced lung injury (VILI) and possibly reduce acute respiratory distress syndrome (ARDS)-related mortality. However, several randomized clinical trials have failed to show any significant clinical benefit of a ventilation strategy applying higher positive end-expiratory pressure (PEEP) and low tidal volume.Dispute regarding the optimal levels of PEEP in ARDS patients represents the substrate for a translational research effort from the bedside to the bench, driving animal studies aimed at elucidating which ventilation strategies reduce biotrauma, considered one of the most important driving forces of VILI and ARDS-related multi-organ failure and mortality. Inappropriate values for end-inspiratory or end-expiratory pressure have clear potential to damage a lung predisposed to VILI. In the heterogeneous environment of the ARDS 'baby lung', lung recruitment and the avoidance of tidal overstretch with high-frequency oscillation ventilation or conventional mechanical ventilation, guided by respiratory mechanics, appears to reduce VILI.
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Albert S, Kubiak BD, Vieau CJ, Roy SK, DiRocco J, Gatto LA, Young JL, Tripathi S, Trikha G, Lopez C, Nieman GF. Comparison of "open lung" modes with low tidal volumes in a porcine lung injury model. J Surg Res 2010; 166:e71-81. [PMID: 21195426 DOI: 10.1016/j.jss.2010.10.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 10/01/2010] [Accepted: 10/19/2010] [Indexed: 11/27/2022]
Abstract
BACKGROUND Ventilator strategies that maintain an "open lung" have shown promise in treating hypoxemic patients. We compared three "open lung" strategies with standard of care low tidal volume ventilation and hypothesized that each would diminish physiologic and histopathologic evidence of ventilator induced lung injury (VILI). MATERIALS AND METHODS Acute lung injury (ALI) was induced in 22 pigs via 5% Tween and 30-min of injurious ventilation. Animals were separated into four groups: (1) low tidal volume ventilation (LowVt -6 mL/kg); (2) high-frequency oscillatory ventilation (HFOV); (3) airway pressure release ventilation (APRV); or (4) recruitment and decremental positive-end expiratory pressure (PEEP) titration (RM+OP) and followed for 6 h. Lung and hemodynamic function was assessed on the half-hour. Bronchoalveolar lavage fluid (BALF) was analyzed for cytokines. Lung tissue was harvested for histologic analysis. RESULTS APRV and HFOV increased PaO(2)/FiO(2) ratio and improved ventilation. APRV reduced BALF TNF-α and IL-8. HFOV caused an increase in airway hemorrhage. RM+OP decreased SvO(2), increased PaCO(2), with increased inflammation of lung tissue. CONCLUSION None of the "open lung" techniques were definitively superior to LowVt with respect to VILI; however, APRV oxygenated and ventilated more effectively and reduced cytokine concentration compared with LowVt with nearly indistinguishable histopathology. These data suggest that APRV may be of potential benefit to critically ill patients but other "open lung" strategies may exacerbate injury.
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Affiliation(s)
- Scott Albert
- Department of Surgery, Upstate Medical University, Syracuse, New York 13210, USA
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Jauncey-Cooke JI, Bogossian F, East CE. Lung protective ventilation strategies in paediatrics-A review. Aust Crit Care 2010; 23:81-8. [PMID: 20047842 DOI: 10.1016/j.aucc.2009.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 11/03/2009] [Accepted: 11/10/2009] [Indexed: 10/20/2022] Open
Abstract
Ventilator Associated Lung Injury (VALI) is an iatrogenic phenomena that significantly impacts on the morbidity and mortality of critically ill patients. The hazards associated with mechanical ventilation are becoming increasingly understood courtesy of a large body of research. Barotrauma, volutrauma and biotrauma all play a role in VALI. Concomitant to this growth in understanding is the development of strategies to reduce the deleterious impact of mechanical ventilation. The majority of the research is based upon adult populations but with careful extrapolation this review will focus on paediatrics. This review article describes the physiological basis of VALI and discusses the various lung protective strategies that clinicians can employ to minimise its incidence and optimise outcomes for paediatric patients.
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Affiliation(s)
- Jacqui I Jauncey-Cooke
- The University of Queensland, School of Nursing and Midwifery, Herston, Australia; Clinical Nurse, PICU, Mater Children's Hospital, South Brisbane, Queensland, Australia.
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Aspros AJ, Coto CG, Lewis JF, Veldhuizen RA. High-frequency oscillation and surfactant treatment in an acid aspiration model. Can J Physiol Pharmacol 2010; 88:14-20. [DOI: 10.1139/y09-096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both exogenous surfactant therapy and high-frequency oscillation (HFO) have been proposed as clinical interventions in acute respiratory distress syndrome (ARDS). The combination of these 2 interventions has not been studied in a relevant model of ARDS. It was hypothesized that surfactant treatment combined with HFO is superior to either surfactant treatment or HFO alone in a model of ARDS. Adult rats had lung injury induced by instillation of 0.1 mol/L HCl, followed by randomization to one of 4 groups: Conventional mechanical ventilation (CMV) + air (no treatment), CMV + surfactant, HFO + air, and HFO + surfactant. Oxygenation, lung compliance, surfactant, and cytokine concentrations in the lung lavage were analyzed. The results showed superior oxygenation in HFO ventilated animals regardless of surfactant treatment compared with CMV. Nonsurfactant-treated animals ventilated with HFO had a significantly greater proportion of large aggregates, and had greater lung compliance compared with non-surfactant-treated animals ventilated with CMV. Surfactant therapy combined with HFO provided no advantages with respect to these outcomes. These data suggest an advantage of HFO over CMV when exogenous surfactant was not given, and that surfactant treatment combined with HFO was not superior to HFO ventilation alone.
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Affiliation(s)
- Alexander J. Aspros
- Lawson Health Research Institute, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medicine, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
| | - Claudia G. Coto
- Lawson Health Research Institute, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medicine, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
| | - James F. Lewis
- Lawson Health Research Institute, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medicine, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
| | - Ruud A.W. Veldhuizen
- Lawson Health Research Institute, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medicine, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, 268 Grosvenor Street, London, ON N6A 4V2, Canada
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Abstract
The number of cases of mortality after burn injury continues to decline, in part because of advances in respiratory, fluid, and sepsis management. However, care needs to be exercised in the application of these new techniques and technologies, many of which have never been assessed or have been incompletely studied in patients who have burn injury. Use of any of these advances in critical care needs to be individualized for any given patient and altered based on the patient's response to therapy. Future advances in the critical care of burns will require multicenter prospective trials at dedicated burn centers to define the optimal therapy for the patient who has burn injury.
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Oscillation after inhalation: high frequency oscillatory ventilation in burn patients with the acute respiratory distress syndrome and co-existing smoke inhalation injury. J Burn Care Res 2009; 30:119-27. [PMID: 19060765 DOI: 10.1097/bcr.0b013e3181920fe6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to evaluate the effectiveness of, and complications associated with High Frequency Oscillatory Ventilation (HFOV) in burn patients with the Acute Respiratory Distress Syndrome (ARDS) who have had a smoke inhalation injury, and to compare with those without an inhalation injury. Burn patients with progressive oxygenation failure from ARDS while on conventional mechanical ventilation were placed on HFOV as a "rescue" ventilation modality. There were 19 patients with burn + inhalation injury and 30 patients with burn only. Burned patients with ARDS but without inhalation injury had significant temporal improvement in the oxygenation index from 27 +/- 8 on conventional mechanical ventilation to 17 +/- 6 within 48 hours of initiating HFOV. However, burned patients with ARDS and smoke inhalation injury did not achieve significant or even eventual improvements in oxygenation index with HFOV. There was also a trend towards higher rates of early HFOV failure and severe hypercapnia while on HFOV among the patients with inhalation injury. Delivery of nebulized bronchodilators, heparin and n-acetyl cysteine, normally mainstays of smoke inhalation therapy, was impossible during HFOV. The presence of a smoke inhalation injury appears to impair the response to HFOV when this ventilation modality is instituted for ARDS-related oxygenation failure. Severe hypercapnia tended to be more frequent during HFOV among patients with smoke inhalation. These findings, combined with the difficulties in delivery of nebulized medications during HFOV suggest that HFOV may not be the optimal "rescue" ventilation modality in cases of ARDS if there has been an inhalation injury.
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Ji C, Na W, Fei X, Sheng-Jun C, Jia-Bi Z. Characterization, lung targeting profile and therapeutic efficiency of dipyridamole liposomes. J Drug Target 2008; 14:717-24. [PMID: 17162741 DOI: 10.1080/10611860600916586] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury (ALI). Its pathogenesis is closely linked with reactive oxygen species (ROS). Antioxidation has been considered as an efficient treatment. Besides, liposomes are widely investigated as potential drug carriers due to their ability to protect and carry drug molecules to the target organ such as the lung. The present study was undertaken to investigate whether dipyridamole (DIP), delivered as a liposomal preparation, can ameliorate the lipopolysaccharides (LPS)-induced ALI due to the changes of its biodistribution. First, the liposomes entrapping DIP were prepared by film hydration for treating ARDS. Subsequently, the characterizations including entrapment efficiency, size, span and micrograph of DIP liposomes were measured. The concentration change of DIP in tissues and plasma of mice after intravenous administration of DIP injection and DIP liposomes was determined by RP-HPLC and calculated to lung targeting parameters. To prove the therapeutic efficiency, the effects of DIP liposomes on LPS-induced ALI were studied compared with DIP injection. The results showed DIP liposomes have the relative high entrapment efficiency and satisfying particle size. Compared with DIP injection, the liposomes increased the accumulation of DIP in the lung on a vast scale. Furthermore, DIP liposomes alleviated the ALI induced by LPS significantly. All of the results suggested that DIP liposomes have the potential efficacy in treating ALI/ARDS due to their obvious lung targeting.
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Affiliation(s)
- Cheng Ji
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China.
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Siau C, Stewart TE. Current role of high frequency oscillatory ventilation and airway pressure release ventilation in acute lung injury and acute respiratory distress syndrome. Clin Chest Med 2008; 29:265-75, vi. [PMID: 18440436 DOI: 10.1016/j.ccm.2008.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Lung protective ventilatory strategies using conventional ventilators have resulted in decreased mortality in adult patients who have acute lung injury and acute respiratory distress syndrome. Conceptually, high frequency oscillatory ventilation and airway pressure release ventilation appear not only able to fulfill the goals of lung protection, but also to offer some additional advantages over conventional ventilation. Although early data for each of these modes in adults have been encouraging, their widespread use--particularly outside of a rescue situation--cannot be recommended without further evidence.
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Affiliation(s)
- Chuin Siau
- Interdepartmental Division of Critical Care Medicine, University of Toronto, 220 Victoria Street, Suite 1807, Toronto, Ontario, Canada M5B 2R6
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Matute-Bello G, Frevert CW, Martin TR. Animal models of acute lung injury. Am J Physiol Lung Cell Mol Physiol 2008; 295:L379-99. [PMID: 18621912 PMCID: PMC2536793 DOI: 10.1152/ajplung.00010.2008] [Citation(s) in RCA: 1233] [Impact Index Per Article: 77.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acute lung injury in humans is characterized histopathologically by neutrophilic alveolitis, injury of the alveolar epithelium and endothelium, hyaline membrane formation, and microvascular thrombi. Different animal models of experimental lung injury have been used to investigate mechanisms of lung injury. Most are based on reproducing in animals known risk factors for ARDS, such as sepsis, lipid embolism secondary to bone fracture, acid aspiration, ischemia-reperfusion of pulmonary or distal vascular beds, and other clinical risks. However, none of these models fully reproduces the features of human lung injury. The goal of this review is to summarize the strengths and weaknesses of existing models of lung injury. We review the specific features of human ARDS that should be modeled in experimental lung injury and then discuss specific characteristics of animal species that may affect the pulmonary host response to noxious stimuli. We emphasize those models of lung injury that are based on reproducing risk factors for human ARDS in animals and discuss the advantages and disadvantages of each model and the extent to which each model reproduces human ARDS. The present review will help guide investigators in the design and interpretation of animal studies of acute lung injury.
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Affiliation(s)
- Gustavo Matute-Bello
- Medical Research Service of the Veterans Affairs/Puget Sound Health Care System, 815 Mercer St., Seattle, WA 98109, USA
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Muellenbach RM, Wunder C, Brederlau J. High-frequency ventilation is/is not the optimal physiological approach to ventilate ARDS patients. J Appl Physiol (1985) 2008; 104:1239. [PMID: 18385297 DOI: 10.1152/japplphysiol.00153.2008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Rossi FS, Mascaretti RS, Haddad LB, Freddi NA, Mauad T, Rebello CM. Utilization of the lower inflection point of the pressure-volume curve results in protective conventional ventilation comparable to high frequency oscillatory ventilation in an animal model of acute respiratory distress syndrome. Clinics (Sao Paulo) 2008; 63:237-44. [PMID: 18438579 PMCID: PMC2664200 DOI: 10.1590/s1807-59322008000200013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 12/31/2007] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume curve as the determinant of positive end-expiratory pressure to obtain similar levels of recruitment and alveolar stability. METHODS After lung lavage of adult rabbits and lower inflection point determination, two groups were randomized: conventional (positive end-expiratory pressure = lower inflection point; tidal volume=6 ml/kg) and high frequency ventilation (mean airway pressures= lower inflection point +4 cmH2O). Blood gas and hemodynamic data were recorded over 4 h. After sacrifice, protein analysis from lung lavage and histologic evaluation were performed. RESULTS The oxygenation parameters, protein and histological data were similar, except for the fact that significantly more normal alveoli were observed upon protective ventilation. High frequency ventilation led to lower PaCO2 levels. DISCUSSION Determination of the lower inflection point of the pressure-volume curve is important for setting the minimum end expiratory pressure needed to keep the airways opened. This is useful when comparing different strategies to treat severe respiratory insufficiency, optimizing conventional ventilation, improving oxygenation and reducing lung injury. CONCLUSIONS Utilization of the lower inflection point of the pressure-volume curve in the ventilation strategies considered in this study resulted in comparable efficacy with regards to oxygenation and hemodynamics, a high PaCO2 level and a lower pH. In addition, a greater number of normal alveoli were found after protective conventional ventilation in an animal model of acute respiratory distress syndrome.
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Affiliation(s)
- Felipe S. Rossi
- Experimental Research Unit (LIM 30), Department of Pediatrics, São Paulo University Medical School - São Paulo/SP, Brazil
| | - Renata Suman Mascaretti
- Experimental Research Unit (LIM 30), Department of Pediatrics, São Paulo University Medical School - São Paulo/SP, Brazil
| | - Luciana B. Haddad
- Experimental Research Unit (LIM 30), Department of Pediatrics, São Paulo University Medical School - São Paulo/SP, Brazil
| | - Norberto A. Freddi
- Experimental Research Unit (LIM 30), Department of Pediatrics, São Paulo University Medical School - São Paulo/SP, Brazil
| | - Thais Mauad
- Department of Pathology, São Paulo University Medical School - São Paulo/ SP, Brazil.
| | - Celso M. Rebello
- Experimental Research Unit (LIM 30), Department of Pediatrics, São Paulo University Medical School - São Paulo/SP, Brazil
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Hua YM, Lien SH, Liu TY, Lee CM, Yuh YS. A decremental PEEP trial for determining open-lung PEEP in a rabbit model of acute lung injury. Pediatr Pulmonol 2008; 43:371-80. [PMID: 18293413 DOI: 10.1002/ppul.20780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A positive end-expiratory pressure (PEEP) above the lower inflection point (LIP) of the pressure-volume curve has been thought necessary to maintain recruited lung volume in acute lung injury (ALI). We used a strategy to identify the level of open-lung PEEP (OLP) by detecting the maximum tidal compliance during a decremental PEEP trial (DPT). We performed a randomized controlled study to compare the effect of the OLP to PEEP above LIP and zero PEEP on pulmonary mechanics, gas exchange, hemodynamic change, and lung injury in 26 rabbits with ALI. After recruitment maneuver, the lavage-injured rabbits received DPTs to identify the OLP. Animals were randomized to receive volume controlled ventilation with either: (a) PEEP = 0 cm H2O (ZEEP); (b) PEEP = 2 cm H2O above OLP (OLP + 2); or (c) PEEP = 2 cm H2O above LIP (LIP + 2). Peak inspiratory pressure and mean airway pressure were recorded and arterial blood gases were analyzed every 30 min. Mean blood pressure and heart rate were monitored continuously. Lung injury severity was assessed by lung wet/dry weight ratio. Animals in OLP + 2 group had less lung injury as well as relatively better compliance, more stable pH, and less hypercapnia compared to the LIP + 2 and ZEEP groups. We concluded that setting PEEP according to the OLP identified by DPTs is an effective method to attenuate lung injury. This strategy could be used as an indicator for optimal PEEP. The approach is simple and noninvasive and may be of clinical interest.
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Affiliation(s)
- Yi-Ming Hua
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
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Rebuttal from Drs. Ferguson and Slutsky. J Appl Physiol (1985) 2008. [DOI: 10.1152/japplphysiol.01226.2007b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Ferguson ND, Slutsky AS. Point: High-frequency ventilation is the optimal physiological approach to ventilate ARDS patients. J Appl Physiol (1985) 2007; 104:1230-1. [PMID: 18048584 DOI: 10.1152/japplphysiol.01226.2007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Niall D Ferguson
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
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Costa E, Amato M. Maintenance of end-expiratory recruitment with increased respiratory rate after saline-lavage lung injury. J Appl Physiol (1985) 2007; 102:2414; author reply 2415. [PMID: 17551113 DOI: 10.1152/japplphysiol.00154.2007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Rationale for High-Frequency Oscillation as a Primary Lung-Protective Mode in Patients with ALI/ARDS. Intensive Care Med 2007. [DOI: 10.1007/978-0-387-49518-7_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Allardet-Servent J, Bregeon F, Delpierre S, Steinberg JG, Payan MJ, Ravailhe S, Papazian L. High-frequency percussive ventilation attenuates lung injury in a rabbit model of gastric juice aspiration. Intensive Care Med 2007; 34:91-100. [PMID: 17885748 DOI: 10.1007/s00134-007-0848-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 08/04/2007] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To test the effects of high-frequency percussive ventilation (HFPV) compared with high-frequency oscillatory ventilation (HFOV) and low-volume conventional mechanical ventilation (LVCMV), on lung injury course in a gastric juice aspiration model. DESIGN Prospective, randomized, controlled, in-vivo animal study. SETTING University animal research laboratory. SUBJECTS Forty-three New Zealand rabbits. INTERVENTIONS Lung injury was induced by intratracheal instillation of human gastric juice in order to achieve profound hypoxaemia (PaO2/FIO2< or =50). Animals were ventilated for 4h after randomization in one of the following four groups: HFPV (median pressure 15cmH2O); LVCMV (VT 6mlkg(-1) and PEEP set to reach 15cmH2O plateau pressure); HFOV (mean pressure 15cmH2O); and a high-volume control group HVCMV (VT 12ml kg(-1) and ZEEP). MEASUREMENTS AND RESULTS Static respiratory compliance increased after the ventilation period in the HFPV, LVMCV and HFOV groups, in contrast with the HVCMV group. PaO2/FIO2 improved similarly in the HFPV, LVCMV and HFOV groups, and remained lower in the HVCMV group than in the three others. Lung oedema, myeloperoxidase and histological lung injury score were higher in the HVCMV group, but not different among all others. Arterial lactate markedly increased after 4h of ventilation in the HVCMV group, while lower but similar levels were observed in the three other groups. CONCLUSION HFPV, like HFOV and protective CMV, improves respiratory mechanics and oxygenation, and attenuates lung damage. The HFPV provides attractive lung protection, but further studies should confirm these results before introducing HFPV into the clinical arena.
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Affiliation(s)
- Jérôme Allardet-Servent
- Service de Réanimation Médicale, Hôpital Sainte-Marguerite, 270 Boulevard Sainte-Marguerite, 13274 Marseille Cedex 9, France.
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Abstract
High-frequency oscillatory ventilation (HFOV) is characterized by the rapid delivery of small tidal volumes (Vts) of gas and the application of high mean airway pressures (mPaws). These characteristics make HFOV conceptually attractive as an ideal lung-protective ventilatory mode for the management of ARDS, as the high mPaws prevent cyclical derecruitment of the lung and the small Vts limit alveolar overdistension. In this review, we will summarize the literature describing the use of HFOV in adult patients with ARDS. In addition, we will discuss recent experimental studies of HFOV that have advanced our understanding of its mechanical properties. We identified 2 randomized controlled trials (RCTs) and 12 case series evaluating HFOV in adults with ARDS. In these studies, HFOV appears to be safe and consistently improves oxygenation when used as a rescue mode of ventilation in patients with severe ARDS. The two RCTs comparing HFOV to conventional ventilation revealed encouraging results but failed to show a mortality benefit of HFOV over conventional ventilation. Further research is needed to identify optimal patient selection, technique, the actual Vt delivered, and the role of combining HFOV with other interventions, such as recruitment maneuvers, prone positioning, and nitric oxide.
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Affiliation(s)
- Kenneth P.W. Chan
- Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | - Thomas E. Stewart
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Sangeeta Mehta
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
- Correspondence to: Sangeeta Mehta, MD, Mt. Sinai Hospital, 600 University Ave, Room 18–216, Toronto, ON, Canada M5G 1X5
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Ferguson ND, Villar J, Slutsky AS. Understanding high-frequency oscillation: lessons from the animal kingdom. Intensive Care Med 2007; 33:1316-8. [PMID: 17563881 DOI: 10.1007/s00134-007-0706-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 04/23/2007] [Indexed: 11/26/2022]
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Abstract
Mechanical ventilation, although essential in taking care of acute lung injury and widely used during surgical procedures worldwide, remains a highly debated field. Clinical trials in the last decade have shown convincingly that mechanical ventilation can result in additional mortality in patients with acute lung injury. This understanding has resulted in a resurged interest in mechanical ventilation, and especially in techniques and strategies to further improve mechanical ventilation. This article discusses physiological principles to improve the understanding of mechanical ventilation.
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Affiliation(s)
- Jack J Haitsma
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Saint Michael's Hospital, 30 Bond Street, Queen wing 4-042, Toronto, Ontario, Canada M5B 1W8.
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Karmrodt J, David M, Yuan S, Markstaller K. Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2007; 10:R138. [PMID: 16999870 PMCID: PMC1751068 DOI: 10.1186/cc5052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 09/04/2006] [Accepted: 09/25/2006] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using high-frequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. METHODS With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar for 2.5 minutes, and a stepwise decrease of the CDP (5 mbar every 5 minute) from 45 to 20 mbar. The TPP level was identified during the decrease in CDP, which assured a change of the PaO2/FIO2 ratio < 25% compared with maximum lung recruitment at CDP of 45 mbar (CDP45). Data are presented as the median (25th-75th percentile); differences between measurements are determined by Friedman repeated-measures analysis on ranks and multiple comparisons (Tukey's test). The level of significance was set at P < 0.05. RESULTS The PaO2/FiO2 ratio increased from 99.1 (56.2-128) Torr at PCV post-lavage to 621 (619.4-660.3) Torr at CDP45 (CDP45) (P < 0.031). The pulmonary shunt fraction decreased from 51.8% (49-55%) at PCV post-lavage to 1.03% (0.4-3%) at CDP45 (P < 0.05). The cardiac output and stroke volume decreased at CDP45 (P < 0.05) compared with PCV, whereas the heart rate, mean arterial pressure, and intrathoracic blood volume remained unchanged. A TPP of 25.5 (17-32) mbar was required to preserve a difference in PaO2/FIO2 ratio < 25% related to CDP45; this TPP was achieved at a CDP of 35 (25-40) mbar. CONCLUSION This HFOV protocol is easy to perform, and allows a fast determination of an adequate TPP level that preserves oxygenation. Systemic hemodynamics, as a measure of safety, showed no relevant deterioration throughout the procedure.
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Affiliation(s)
- Jens Karmrodt
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Matthias David
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Shying Yuan
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Klaus Markstaller
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
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Fraisse A, Bregeon F, Delpierre S, Gaudart J, Payan MJ, Pugin J, Papazian L. Hemodynamics in experimental gastric juice induced aspiration pneumonitis. Intensive Care Med 2006; 33:300-7. [PMID: 17160420 DOI: 10.1007/s00134-006-0457-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Accepted: 10/19/2006] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To characterize hemodynamic changes during experimental aspiration pneumonitis, paying special attention to echocardiographic assessment. DESIGN AND SETTING Animal study in a university-based research laboratory. SUBJECTS Fourteen mechanically ventilated New Zealand white rabbits INTERVENTIONS We instilled 1 ml/kg human gastric juice (mean pH: 4.1+0.2) intratracheally. Hemodynamic and respiratory parameters were measured every hour for 4 h, associated with a transthoracic echocardiography. MEASUREMENTS AND RESULTS Lung injury occurred within 1 hour with a marked decrease in PaO(2)/FIO(2) and an increase in plateau pressure; after this initial drop the ratio remained stable throughout the experiment. Seven rabbits experienced only a mild to moderate alteration in lung oxygenation function as defined by a PaO(2)/FIO(2) ratio above 200 (group A), while the other seven developed a severe alteration with a ratio below 200 (group B). At the end of the experiment pH and cardiac output were lower in group B than in group A. Using a PaO(2)/FIO(2) threshold value of 150, pH, mean arterial pressure, and cardiac output were lower in the animals with the more severe hypoxemia. Neither left nor right ventricular dysfunction occurred during the experiment, and no animal experienced circulatory failure CONCLUSION Experimental aspiration pneumonitis after intratracheal infusion of human gastric juice is characterized by a stable fall in PaO(2)/FIO(2). Animals with the most severe lung injury experienced a lower systemic arterial pressure, cardiac output, and metabolic acidosis without circulatory failure or cardiac dysfunction.
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Affiliation(s)
- Alain Fraisse
- Cardiologie Pédiatrique, Département de Cardiologie, Hôpital de la Timone, 264 rue St. Pierre, 13385, Marseille Cedex 5, France
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