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Davis JA, Manoach S, Heerdt P, Berlin DA. Management of Respiratory Failure in Hemorrhagic Shock. Ann Am Thorac Soc 2024; 21:993-997. [PMID: 38669620 DOI: 10.1513/annalsats.202310-905cme] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 04/25/2024] [Indexed: 04/28/2024] Open
Abstract
Hemorrhagic shock results in acute respiratory failure due to respiratory muscle fatigue and inadequate pulmonary blood flow. Because positive pressure ventilation can reduce venous return and cardiac output, clinicians should use the minimum possible mean airway pressure during assisted or mechanical ventilation, particularly during episodes of severe hypovolemia. Hypoperfusion also worsens dead space fraction. Therefore, clinicians should monitor capnography during mechanical ventilation and recognize that hypercapnia may be treated with fluid resuscitation rather than increasing minute ventilation.
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Affiliation(s)
- Joshua A Davis
- Division of Pulmonary and Critical Care Medicine, Weill Cornell Medicine, New York, New York; and
| | - Seth Manoach
- Division of Pulmonary and Critical Care Medicine, Weill Cornell Medicine, New York, New York; and
| | - Paul Heerdt
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut
| | - David A Berlin
- Division of Pulmonary and Critical Care Medicine, Weill Cornell Medicine, New York, New York; and
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2
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Rali AS, Tran L, Balakrishna A, Senussi M, Kapur NK, Metkus T, Tedford RJ, Lindenfeld J. Guide to Lung-Protective Ventilation in Cardiac Patients. J Card Fail 2024; 30:829-837. [PMID: 38513887 DOI: 10.1016/j.cardfail.2024.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 03/23/2024]
Abstract
The incidence of acute respiratory insufficiency has continued to increase among patients admitted to modern-day cardiovascular intensive care units. Positive pressure ventilation (PPV) remains the mainstay of treatment for these patients. Alterations in intrathoracic pressure during PPV has distinct effects on both the right and left ventricles, affecting cardiovascular performance. Lung-protective ventilation (LPV) minimizes the risk of further lung injury through ventilator-induced lung injury and, hence, an understanding of LPV and its cardiopulmonary interactions is beneficial for cardiologists.
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Affiliation(s)
- Aniket S Rali
- Division of Cardiovascular Diseases, Vanderbilt University Medical Center, Nashville, TN.
| | - Lena Tran
- Division of Cardiovascular Diseases, Vanderbilt University Medical Center, Nashville, TN
| | - Aditi Balakrishna
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN
| | - Mourad Senussi
- Department of Medicine, Baylor St. Luke's Medical Center, Houston, TX
| | - Navin K Kapur
- Division of Cardiovascular Diseases, Tufts Medical Center, Boston, MA
| | - Thomas Metkus
- Departments of Medicine and Surgery, Divisions of Cardiology and Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ryan J Tedford
- Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC
| | - Joann Lindenfeld
- Division of Cardiovascular Diseases, Vanderbilt University Medical Center, Nashville, TN
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Fumagalli J, Pesenti A. Ventilation during extracorporeal gas exchange in acute respiratory distress syndrome. Curr Opin Crit Care 2024; 30:69-75. [PMID: 38085872 PMCID: PMC10919266 DOI: 10.1097/mcc.0000000000001125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
PURPOSE OF REVIEW Accumulating evidence ascribes the benefit of extracorporeal gas exchange, at least in most severe cases, to the provision of a lung healing environment through the mitigation of ventilator-induced lung injury (VILI) risk. In spite of pretty homogeneous criteria for extracorporeal gas exchange application (according to the degree of hypoxemia/hypercapnia), ventilatory management during extracorporeal membrane oxygenation (ECMO)/carbon dioxide removal (ECCO 2 R) varies across centers. Here we summarize the recent evidence regarding the management of mechanical ventilation during extracorporeal gas exchange for respiratory support. RECENT FINDINGS At present, the most common approach to protect the native lung against VILI following ECMO initiation involves lowering tidal volume and driving pressure, making modest reductions in respiratory rate, while typically maintaining positive end-expiratory pressure levels unchanged.Regarding ECCO 2 R treatment, higher efficiency devices are required in order to reduce significantly respiratory rate and/or tidal volume. SUMMARY The best compromise between reduction of native lung ventilatory load, extracorporeal gas exchange efficiency, and strategies to preserve lung aeration deserves further investigation.
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Affiliation(s)
- Jacopo Fumagalli
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e cura a Carattere Scientifico Ca’ Granda Ospedale Maggiore Policlinico
| | - Antonio Pesenti
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e cura a Carattere Scientifico Ca’ Granda Ospedale Maggiore Policlinico
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
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Mojoli F, Pozzi M, Arisi E. Setting positive end-expiratory pressure: using the pressure-volume curve. Curr Opin Crit Care 2024; 30:35-42. [PMID: 38085871 DOI: 10.1097/mcc.0000000000001127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
PURPOSE OF REVIEW To discuss the role of pressure-volume curve (PV curve) in exploring elastic properties of the respiratory system and setting mechanical ventilator to reduce ventilator-induced lung injury. RECENT FINDINGS Nowadays, quasi-static PV curves and loops can be easily obtained and analyzed at the bedside without disconnection of the patient from the ventilator. It is shown that this tool can provide useful information to optimize ventilator setting. For example, PV curves can assess for patient's individual potential for lung recruitability and also evaluate the risk for lung injury of the ongoing mechanical ventilation setting. SUMMARY In conclusion, PV curve is an easily available bedside tool: its correct interpretation can be extremely valuable to enlighten potential for lung recruitability and select a high or low positive end-expiratory pressure (PEEP) strategy. Furthermore, recent studies have shown that PV curve can play a significant role in PEEP and driving pressure fine tuning: clinical studies are needed to prove whether this technique will improve outcome.
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Affiliation(s)
- Francesco Mojoli
- Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Unit of Anesthesia and Intensive Care, University of Pavia, Pavia, Italy
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Marco Pozzi
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Eric Arisi
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
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Abplanalp LA, Ionescu F, Calvo-Ayala E, Yu L, Nair GB. Static Respiratory System Compliance as a Predictor of Extubation Failure in Patients with Acute Respiratory Failure. Lung 2023:10.1007/s00408-023-00625-7. [PMID: 37300706 DOI: 10.1007/s00408-023-00625-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/25/2023] [Indexed: 06/12/2023]
Abstract
PURPOSE Ventilator weaning protocols rely in part on objective indices to best predict extubation failure in the critically ill. We investigated static respiratory system compliance (RC) as a predictor of extubation failure, in comparison to extubation readiness using rapid shallow breathing index (RSBI). MATERIAL AND METHODS This was a cross-sectional, multi-institutional study of mechanically ventilated patients admitted between 12/01/2017 and 12/01/2019. All patients older than 18 years with a documented spontaneous breathing trial and extubation trial were included. RC and RSBI were calculated prior to the extubation trial. The primary outcome was extubation failure-defined as need for reintubation within 72 h from time of extubation. RESULTS Of the 2263 patients, 55.8% were males with a mean age of 68 years. The population consisted mostly of Caucasians (73%) and African Americans (20.4%). 274 (12.1%) patients required reintubation within 72 h. On multivariate logistic regression after adjusting for age, sex, body mass index (BMI), admission Sequential Organ Failure Assessment (SOFA) score, number of ventilator days, and the P/F ratio on the day of extubation, RC remained the strongest predictor for extubation failure at 24 h (aOR 1.45; 95% CI 1.00-2.10) and 72 h (aOR 1.58; 95% CI 1.15-2.17). There was no significant association between RSBI and extubation failure at 24 (aOR 1.00; 95% CI 0.99-1.01) or at 72 h (aOR 1.00; 95% CI 0.99-1.01). CONCLUSION RC measured on the day of extubation is a promising physiological discriminant to potentially risk stratify patients with acute respiratory failure for extubation readiness. We recommend further validation studies in prospective cohorts.
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Affiliation(s)
- Lauren A Abplanalp
- Division of Pulmonary and Critical Care, Beaumont Health, Royal Oak, MI, USA
- OUWB School of Medicine, Rochester, MI, USA
| | - Filip Ionescu
- OUWB School of Medicine, Rochester, MI, USA
- Moffitt Cancer Center, University of South Florida Morsani Medical School, Tampa, FL, USA
| | - Enrique Calvo-Ayala
- Division of Pulmonary and Critical Care, Beaumont Health, Royal Oak, MI, USA
- OUWB School of Medicine, Rochester, MI, USA
| | - Limin Yu
- Department of Pathology, Beaumont Health, Royal Oak, MI, USA
| | - Girish B Nair
- Division of Pulmonary and Critical Care, Beaumont Health, Royal Oak, MI, USA.
- OUWB School of Medicine, Rochester, MI, USA.
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Web Applications for Teaching the Respiratory System: Content Validation. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The subject of respiratory mechanics has complex characteristics, functions, and interactions that can be difficult to understand in training and medical education contexts. As such, education strategies based on computational simulations comprise useful tools, but their application in the medical area requires stricter validation processes. This paper shows a statistical and a Delphi validation for two modules of a web application used for respiratory system learning: (I) “Anatomy and Physiology” and (II) “Work of Breathing Indexes”. For statistical validation, population and individual analyses were made using a database of healthy men to compare experimental and model-predicted data. For both modules, the predicted values followed the trend marked by the experimental data in the population analysis, while in the individual analysis, the predicted errors were 9.54% and 25.38% for maximal tidal volume and airflow, respectively, and 6.55%, 9.33%, and 11.77% for rapid shallow breathing index, work of breathing, and maximal inspiratory pressure, respectively. For the Delphi validation, an average higher than 4 was obtained after health professionals evaluated both modules from 1 to 5. In conclusion, both modules are good tools for respiratory system learning processes. The studied parameters behaved consistently with the expressions that describe ventilatory dynamics and were correlated with experimental data; furthermore, they had great acceptance by specialists.
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Should we continue searching for the single best PEEP? Intensive Care Med Exp 2022; 10:9. [PMID: 35312894 PMCID: PMC8936031 DOI: 10.1186/s40635-022-00438-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/16/2022] [Indexed: 11/23/2022] Open
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Lee JWW, Chiew YS, Wang X, Mat Nor MB, Chase JG, Desaive T. Stochastic integrated model-based protocol for volume-controlled ventilation setting. Biomed Eng Online 2022; 21:13. [PMID: 35148759 PMCID: PMC8832735 DOI: 10.1186/s12938-022-00981-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/21/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Mechanical ventilation (MV) is the primary form of care for respiratory failure patients. MV settings are based on general clinical guidelines, intuition, and experience. This approach is not patient-specific and patients may thus experience suboptimal, potentially harmful MV care. This study presents the Stochastic integrated VENT (SiVENT) protocol which combines model-based approaches of the VENT protocol from previous works, with stochastic modelling to take the variation of patient respiratory elastance over time into consideration. METHODS A stochastic model of Ers is integrated into the VENT protocol from previous works to develop the SiVENT protocol, to account for both intra- and inter-patient variability. A cohort of 20 virtual MV patients based on retrospective patient data are used to validate the performance of this method for volume-controlled (VC) ventilation. A performance evaluation was conducted where the SiVENT and VENT protocols were implemented in 1080 instances each to compare the two protocols and evaluate the difference in reduction of possible MV settings achieved by each. RESULTS From an initial number of 189,000 possible MV setting combinations, the VENT protocol reduced this number to a median of 10,612, achieving a reduction of 94.4% across the cohort. With the integration of the stochastic model component, the SiVENT protocol reduced this number from 189,000 to a median of 9329, achieving a reduction of 95.1% across the cohort. The SiVENT protocol reduces the number of possible combinations provided to the user by more than 1000 combinations as compared to the VENT protocol. CONCLUSIONS Adding a stochastic model component into a model-based approach to selecting MV settings improves the ability of a decision support system to recommend patient-specific MV settings. It specifically considers inter- and intra-patient variability in respiratory elastance and eliminates potentially harmful settings based on clinically recommended pressure thresholds. Clinical input and local protocols can further reduce the number of safe setting combinations. The results for the SiVENT protocol justify further investigation of its prediction accuracy and clinical validation trials.
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Affiliation(s)
- Jay Wing Wai Lee
- School of Engineering, Monash University Malaysia, Subang Jaya, Selangor Malaysia
| | - Yeong Shiong Chiew
- School of Engineering, Monash University Malaysia, Subang Jaya, Selangor Malaysia
| | - Xin Wang
- School of Engineering, Monash University Malaysia, Subang Jaya, Selangor Malaysia
| | - Mohd Basri Mat Nor
- Kulliyah of Medicine, International Islamic University Malaysia, Kuantan, Malaysia
| | - J. Geoffrey Chase
- Center of Bioengineering, University of Canterbury, Christchurch, New Zealand
| | - Thomas Desaive
- GIGA In-Silico Medicine, University of Liege, Liege, Belgium
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Lee JWW, Chiew YS, Wang X, Tan CP, Mat Nor MB, Cove ME, Damanhuri NS, Chase JG. Protocol conception for safe selection of mechanical ventilation settings for respiratory failure Patients. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 214:106577. [PMID: 34936946 DOI: 10.1016/j.cmpb.2021.106577] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/17/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE Mechanical ventilation is the primary form of care provided to respiratory failure patients. Limited guidelines and conflicting results from major clinical trials means selection of mechanical ventilation settings relies heavily on clinician experience and intuition. Determining optimal mechanical ventilation settings is therefore difficult, where non-optimal mechanical ventilation can be deleterious. To overcome these difficulties, this research proposes a model-based method to manage the wide range of possible mechanical ventilation settings, while also considering patient-specific conditions and responses. METHODS This study shows the design and development of the "VENT" protocol, which integrates the single compartment linear lung model with clinical recommendations from landmark studies, to aid clinical decision-making in selecting mechanical ventilation settings. Using retrospective breath data from a cohort of 24 patients, 3,566 and 2,447 clinically implemented VC and PC settings were extracted respectively. Using this data, a VENT protocol application case study and clinical comparison is performed, and the prediction accuracy of the VENT protocol is validated against actual measured outcomes of pressure and volume. RESULTS The study shows the VENT protocols' potential use in narrowing an overwhelming number of possible mechanical ventilation setting combinations by up to 99.9%. The comparison with retrospective clinical data showed that only 33% and 45% of clinician settings were approved by the VENT protocol. The unapproved settings were mainly due to exceeding clinical recommended settings. When utilising the single compartment model in the VENT protocol for forecasting peak pressures and tidal volumes, median [IQR] prediction error values of 0.75 [0.31 - 1.83] cmH2O and 0.55 [0.19 - 1.20] mL/kg were obtained. CONCLUSIONS Comparing the proposed protocol with retrospective clinically implemented settings shows the protocol can prevent harmful mechanical ventilation setting combinations for which clinicians would be otherwise unaware. The VENT protocol warrants a more detailed clinical study to validate its potential usefulness in a clinical setting.
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Affiliation(s)
- Jay Wing Wai Lee
- School of Engineering, Monash University Malaysia, Selangor, Malaysia.
| | | | - Xin Wang
- School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Chee Pin Tan
- School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Mohd Basri Mat Nor
- Kulliyah of Medicine, International Islamic University Malaysia, Pahang, Malaysia
| | - Matthew E Cove
- Division of Respiratory and Critical Care Medicine, Department of Medicine, National University Health System, Singapore
| | - Nor Salwa Damanhuri
- Faculty of Electrical Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, Pulau Pinang, Malaysia
| | - J Geoffrey Chase
- Center of Bioengineering, University of Canterbury, Christchurch, New Zealand
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10
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Fusina F, Albani F, Crisci S, Morandi A, Tansini F, Beschi R, Rosano A, Natalini G. Respiratory system compliance at the same PEEP level is similar in COVID and non-COVID ARDS. Respir Res 2022; 23:7. [PMID: 35022054 PMCID: PMC8753591 DOI: 10.1186/s12931-022-01930-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/08/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The comparison of respiratory system compliance (Crs) between COVID and non-COVID ARDS patients has been the object of debate, but few studies have evaluated it when considering applied positive end expiratory pressure (PEEP), which is one of the known determinants of Crs itself. The aim of this study was to compare Crs taking into account the applied PEEP. METHODS Two cohorts of patients were created: those with COVID-ARDS and those with non-COVID ARDS. In the whole sample the association between Crs and type of ARDS at different PEEP levels was adjusted for anthropometric and clinical variables. As secondary analyses, patients were matched for predicted functional residual capacity and the same association was assessed. Moreover, the association between Crs and type of ARDS was reassessed at predefined PEEP level of 0, 5, 10, and 15 cmH2O with a propensity score-weighted linear model. RESULTS 367 patients were included in the study, 276 patients with COVID-ARDS and 91 with non-COVID ARDS. The association between Crs and type of ARDS was not significant in both the complete cohorts (p = 0.17) and in the matched cohorts (p = 0.92). This was true also for the propensity score weighted association at PEEP 5, 10 and 15 cmH2O, while it was statistically significant at PEEP 0 (with a median difference of 3 ml/cmH2O, which in our opinion is not clinically significant). CONCLUSIONS The compliance of the respiratory system is similar between COVID ARDS and non-COVID ARDS when calculated at the same PEEP level and while taking into account patients' anthropometric characteristics.
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Affiliation(s)
- Federica Fusina
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy.
| | - Filippo Albani
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
| | - Serena Crisci
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of The Sacred Heart, Rome, Italy
| | - Alessandro Morandi
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
| | - Francesca Tansini
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
- Department of Anesthesia and Intensive Care, University of Insubria, Varese, Lombardia, Italy
| | - Rasula Beschi
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
| | - Antonio Rosano
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
| | - Giuseppe Natalini
- Department of Anesthesia, Intensive Care and Pain Medicine, Fondazione Poliambulanza Hospital, via Bissolati, 57, 25124, Brescia, Italy
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Lagier D, Zeng C, Fernandez-Bustamante A, Melo MFV. Perioperative Pulmonary Atelectasis: Part II. Clinical Implications. Anesthesiology 2022; 136:206-236. [PMID: 34710217 PMCID: PMC9885487 DOI: 10.1097/aln.0000000000004009] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.
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Affiliation(s)
- David Lagier
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Congli Zeng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Marcos F. Vidal Melo
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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12
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Lee JWW, Chiew YS, Wang X, Tan CP, Mat Nor MB, Damanhuri NS, Chase JG. Stochastic Modelling of Respiratory System Elastance for Mechanically Ventilated Respiratory Failure Patients. Ann Biomed Eng 2021; 49:3280-3295. [PMID: 34435276 PMCID: PMC8386681 DOI: 10.1007/s10439-021-02854-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/13/2021] [Indexed: 02/07/2023]
Abstract
While lung protective mechanical ventilation (MV) guidelines have been developed to avoid ventilator-induced lung injury (VILI), a one-size-fits-all approach cannot benefit every individual patient. Hence, there is significant need for the ability to provide patient-specific MV settings to ensure safety, and optimise patient care. Model-based approaches enable patient-specific care by identifying time-varying patient-specific parameters, such as respiratory elastance, Ers, to capture inter- and intra-patient variability. However, patient-specific parameters evolve with time, as a function of disease progression and patient condition, making predicting their future values crucial for recommending patient-specific MV settings. This study employs stochastic modelling to predict future Ers values using retrospective patient data to develop and validate a model indicating future intra-patient variability of Ers. Cross validation results show stochastic modelling can predict future elastance ranges with 92.59 and 68.56% of predicted values within the 5-95% and the 25-75% range, respectively. This range can be used to ensure patients receive adequate minute ventilation should elastance rise and minimise the risk of VILI should elastance fall. The results show the potential for model-based protocols using stochastic model prediction of future Ers values to provide safe and patient-specific MV. These results warrant further investigation to validate its clinical utility.
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Affiliation(s)
- Jay Wing Wai Lee
- School of Engineering, Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia.
| | - Yeong Shiong Chiew
- School of Engineering, Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia.
| | - Xin Wang
- School of Engineering, Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia
| | - Chee Pin Tan
- School of Engineering, Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia
| | - Mohd Basri Mat Nor
- Kulliyah of Medicine, International Islamic University Malaysia, 25200, Kuantan, Pahang, Malaysia
| | - Nor Salwa Damanhuri
- Faculty of Electrical Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, 13500, Bukit Bertajam, Pulau Pinang, Malaysia
| | - J Geoffrey Chase
- Center of Bioengineering, University of Canterbury, Christchurch, 8041, New Zealand
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13
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Hardin CC, Marini JJ. Smoothing the Edges of Lung Protection. Am J Respir Crit Care Med 2021; 203:1212-1214. [PMID: 33503400 PMCID: PMC8456477 DOI: 10.1164/rccm.202101-0111ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- C Corey Hardin
- Division of Pulmonary and Critical Care Medicine Massachusetts General Hospital Boston, Massachusetts
| | - John J Marini
- Department of Medicine Regions Hospital and University of Minnesota St. Paul, Minnesota
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14
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Morton SE, Knopp JL, Tawhai MH, Docherty P, Heines SJ, Bergmans DC, Möller K, Chase JG. Prediction of lung mechanics throughout recruitment maneuvers in pressure-controlled ventilation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 197:105696. [PMID: 32798977 DOI: 10.1016/j.cmpb.2020.105696] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
Mechanical ventilation (MV) is a core therapy in the intensive care unit (ICU). Some patients rely on MV to support breathing. However, it is a difficult therapy to optimise, where inter- and intra- patient variability leads to significantly increased risk of lung damage. Excessive volume and/or pressure can cause volutrauma or barotrauma, resulting in increased length of time on ventilation, length of stay, cost and mortality. Virtual patient modelling has changed care in other areas of ICU medicine, enabling more personalized and optimal care, and have emerged for volume-controlled MV. This research extends this MV virtual patient model into the increasingly more commonly used pressure-controlled MV mode. The simulation methods are extended to use pressure, instead of both volume and flow, as the known input, increasing the output variables to be predicted (flow and its integral, volume). The model and methods are validated using data from N = 14 pressure-control ventilated patients during recruitment maneuvers, with n = 558 prediction tests over changes of PEEP ranging from 2 to 16 cmH2O. Prediction errors for peak inspiratory volume for an increase of 16 cmH2O were 80 [30 - 140] mL (15.9 [8.4 - 31.0]%), with RMS fitting errors of 0.05 [0.03 - 0.12] L. These results show very good prediction accuracy able to guide personalised MV care.
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Affiliation(s)
- Sophie E Morton
- Mechanical Engineering Department, University of Canterbury, Christchurch, New Zealand
| | - Jennifer L Knopp
- Mechanical Engineering Department, University of Canterbury, Christchurch, New Zealand
| | - Merryn H Tawhai
- Auckland Bioengineering Institute, Auckland University, Auckland, New Zealand
| | - Paul Docherty
- Mechanical Engineering Department, University of Canterbury, Christchurch, New Zealand
| | - Serge J Heines
- Department of Intensive Care, School of Medicine, Maastricht University, Maastricht, Netherlands
| | - Dennis C Bergmans
- Department of Intensive Care, School of Medicine, Maastricht University, Maastricht, Netherlands
| | - Knut Möller
- Institute for Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - J Geoffrey Chase
- Mechanical Engineering Department, University of Canterbury, Christchurch, New Zealand.
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15
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Lewandowski K, Bartlett RH. [A critical carol : Being an essay on anemia, suffocation, starvation, and other forms of intensive care, after the manner of Dickens]. Anaesthesist 2020; 69:890-908. [PMID: 33048223 PMCID: PMC7550839 DOI: 10.1007/s00101-020-00835-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Irgendwo in den USA – Einige Tage vor Heiligabend wird der angetrunkene Charlie Cratchit bei dem Versuch, eine Straße zu überqueren, von einem Bus angefahren und schwer verletzt: Rippenserienfraktur, Femur- und Fibulafraktur, Milz- und Pankreaslazeration, Darmrisse. In einem US-amerikanischen Krankenhaus der Maximalversorgung wird er operativ versorgt und anschließend auf die Intensivtherapiestation verlegt und dort kontinuierlich von einem namenlosen, sehr erfahrenen Arzt betreut. Vier Tage vor Heiligabend, erscheint am Patientenbett der Geist des berühmten britischen Physiologen Ernest Henry Starling. Er tritt in einen Dialog mit dem namenlosen Arzt, interessiert sich sehr für den Swan-Ganz-Katheter und verschwindet dann wieder. Die Besuche wiederholen sich in den kommenden 3 Nächten. Einmal kritisiert er Cratchits niedrigen Hämatokrit, beim nächsten Mal zeigt er sich unzufrieden mit der Respiratoreinstellung, und beim letzten Besuch ist er äußerst besorgt über den Ernährungszustand des Patienten. Der namenlose Arzt ist zunächst indigniert über des Geistes Kritik und Belehrungen, erkennt aber, dass darin der Schlüssel zu Cratchits Genesung liegt und handelt letztlich nach seinen Vorschlägen. Mit Erfolg: Nach der vom Geist Starlings angeregten Umstellung der maschinellen Ventilation, Gabe von 3 Erythrozytenkonzentraten und Aufnahme einer parenteralen Ernährung kann Charlie Cratchit am Weihnachtsabend extubiert und am Neujahrstag von der Intensivtherapiestation entlassen werden. In diesem Essay hat Robert Bartlett Charles Dickens’ „Weihnachtsgeschichte“ in die Welt der Intensivmedizin verlegt. Sie soll den Intensivmediziner anregen, therapeutische Interventionen wie maschinelle Ventilation, hämodynamische Interventionen und Gabe von Blutprodukten kritisch zu hinterfragen. Hintergrundinformationen und Kommentare zu den angesprochenen aktuellen Problemen der modernen Intensivmedizin ergänzen den Essay.
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Affiliation(s)
| | - R H Bartlett
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, USA
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16
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Peel JK, Funk DJ, Slinger P, Srinathan S, Kidane B. Positive end-expiratory pressure and recruitment maneuvers during one-lung ventilation: A systematic review and meta-analysis. J Thorac Cardiovasc Surg 2020; 160:1112-1122.e3. [DOI: 10.1016/j.jtcvs.2020.02.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 01/09/2023]
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17
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Marini JJ, Rocco PRM, Gattinoni L. Static and Dynamic Contributors to Ventilator-induced Lung Injury in Clinical Practice. Pressure, Energy, and Power. Am J Respir Crit Care Med 2020; 201:767-774. [PMID: 31665612 PMCID: PMC7124710 DOI: 10.1164/rccm.201908-1545ci] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Ventilation is inherently a dynamic process. The present-day clinical practice of concentrating on the static inflation characteristics of the individual tidal cycle (plateau pressure, positive end-expiratory pressure, and their difference [driving pressure, the ratio of Vt to compliance]) does not take into account key factors shown experimentally to influence ventilator-induced lung injury (VILI). These include rate of airway pressure change (influenced by flow amplitude, inspiratory time fraction, and inspiratory inflation contour) and cycling frequency. Energy must be expended to cause injury, and the product of applied stress and resulting strain determines the energy delivered to the lungs per breathing cycle. Understanding the principles of VILI energetics may provide valuable insights and guidance to intensivists for safer clinical practice. In this interpretive review, we highlight that the injuring potential of the inflation pattern depends upon tissue vulnerability, the number of intolerable high-energy cycles applied in unit time (mechanical power), and the duration of that exposure. Yet, as attractive as this energy/power hypothesis for encapsulating the drivers of VILI may be for clinical applications, we acknowledge that even these all-inclusive and measurable ergonomic parameters (energy per cycle and power) are still too bluntly defined to pinpoint the precise biophysical link between ventilation strategy and tissue injury.
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Affiliation(s)
- John J Marini
- University of Minnesota and Regions Hospital, Minneapolis/St. Paul, Minnesota
| | - Patricia R M Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; and
| | - Luciano Gattinoni
- Department of Anaesthesiology, Emergency and Intensive Care Medicine, University of Göttingen, Göttingen, Germany
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18
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Gattinoni L, Quintel M, Marini JJ. "Less is More" in mechanical ventilation. Intensive Care Med 2020; 46:780-782. [PMID: 32162029 PMCID: PMC7103002 DOI: 10.1007/s00134-020-05981-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 02/20/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Luciano Gattinoni
- Department of Anaesthesiology, Emergency and Intensive Care Medicine, University of Göttingen, Göttingen, Germany.
| | - Michael Quintel
- Department of Anaesthesiology, Emergency and Intensive Care Medicine, University of Göttingen, Göttingen, Germany
| | - John J Marini
- University of Minnesota and Regions Hospital, Minneapolis/St. Paul, MN, USA
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19
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Park S, Oh EJ, Han S, Shin B, Shin SH, Im Y, Son YH, Park HY. Intraoperative Anesthetic Management of Patients with Chronic Obstructive Pulmonary Disease to Decrease the Risk of Postoperative Pulmonary Complications after Abdominal Surgery. J Clin Med 2020; 9:jcm9010150. [PMID: 31935888 PMCID: PMC7019772 DOI: 10.3390/jcm9010150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 12/31/2019] [Accepted: 01/03/2020] [Indexed: 12/12/2022] Open
Abstract
Patients with chronic obstructive pulmonary disease (COPD) exhibit airflow limitation and suboptimal lung function, and they are at high risk of developing postoperative pulmonary complications (PPCs). We aimed to determine the factors that would decrease PPC risk in patients with COPD. We retrospectively analyzed 419 patients with COPD who were registered in our institutional PPC database and had undergone an abdominal surgery under general anesthesia. PPCs comprised respiratory failure, pleural effusion, atelectasis, respiratory infection, and bronchospasm; the presence or type of PPC was diagnosed by respiratory physicians and recorded in the database before this study. Binary logistic regression was used for statistical analysis. Of the 419 patients, 121 patients (28.8%) experienced 200 PPCs. Multivariable analysis showed three modifiable anesthetic factors that could decrease PPC risk: low tidal volume ventilation, restricted fluid infusion, and sugammadex-induced neuromuscular blockade reversal. We found that the 90-day mortality risk was significantly greater in patients with PPC than in those without PPC (5.8% vs. 1.3%; p = 0.016). Therefore, PPC risk in patients with COPD can be decreased if low tidal volume ventilation, restricted fluid infusion, and sugammadex-induced reversal during abdominal surgery are efficiently managed, as these factors result in decreased postoperative mortality.
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Affiliation(s)
- Sukhee Park
- Department of Anesthesiology and Pain Medicine, International St. Mary's Hospital, Catholic Kwandong University School of Medicine, Incheon 22711, Korea
| | - Eun Jung Oh
- Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
- Department of Anesthesiology and Pain Medicine, Kangwon National University Hospital, Chuncheon 24341, Korea
| | - Sangbin Han
- Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Beomsu Shin
- Department of Medicine, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
| | - Sun Hye Shin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Yunjoo Im
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Yong Hoon Son
- Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Hye Yun Park
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
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20
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Matthewman MC, Down J. Mechanical ventilation for the non-anaesthetist 1: physiology and mechanics. Br J Hosp Med (Lond) 2019; 79:C188-C192. [PMID: 30526105 DOI: 10.12968/hmed.2018.79.12.c188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Jim Down
- Consultant in Anaesthetics and Critical Care, University College London Hospital, London
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21
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Predictive Virtual Patient Modelling of Mechanical Ventilation: Impact of Recruitment Function. Ann Biomed Eng 2019; 47:1626-1641. [PMID: 30927170 DOI: 10.1007/s10439-019-02253-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/22/2019] [Indexed: 10/27/2022]
Abstract
Mechanical ventilation is a life-support therapy for intensive care patients suffering from respiratory failure. To reduce the current rate of ventilator-induced lung injury requires ventilator settings that are patient-, time-, and disease-specific. A common lung protective strategy is to optimise the level of positive end-expiratory pressure (PEEP) through a recruitment manoeuvre to prevent alveolar collapse at the end of expiration and to improve gas exchange through recruitment of additional alveoli. However, this process can subject parts of the lung to excessively high pressures or volumes. This research significantly extends and more robustly validates a previously developed pulmonary mechanics model to predict lung mechanics throughout recruitment manoeuvres. In particular, the process of recruitment is more thoroughly investigated and the impact of the inclusion of expiratory data when estimating peak inspiratory pressure is assessed. Data from the McREM trial and CURE pilot trial were used to test model predictive capability and assumptions. For PEEP changes of up to and including 14 cmH2O, the parabolic model was shown to improve peak inspiratory pressure prediction resulting in less than 10% absolute error in the CURE cohort and 16% in the McREM cohort. The parabolic model also better captured expiratory mechanics than the exponential model for both cohorts.
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22
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Major VJ, Chiew YS, Shaw GM, Chase JG. Biomedical engineer's guide to the clinical aspects of intensive care mechanical ventilation. Biomed Eng Online 2018; 17:169. [PMID: 30419903 PMCID: PMC6233601 DOI: 10.1186/s12938-018-0599-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 11/01/2018] [Indexed: 12/16/2022] Open
Abstract
Background Mechanical ventilation is an essential therapy to support critically ill respiratory failure patients. Current standards of care consist of generalised approaches, such as the use of positive end expiratory pressure to inspired oxygen fraction (PEEP–FiO2) tables, which fail to account for the inter- and intra-patient variability between and within patients. The benefits of higher or lower tidal volume, PEEP, and other settings are highly debated and no consensus has been reached. Moreover, clinicians implicitly account for patient-specific factors such as disease condition and progression as they manually titrate ventilator settings. Hence, care is highly variable and potentially often non-optimal. These conditions create a situation that could benefit greatly from an engineered approach. The overall goal is a review of ventilation that is accessible to both clinicians and engineers, to bridge the divide between the two fields and enable collaboration to improve patient care and outcomes. This review does not take the form of a typical systematic review. Instead, it defines the standard terminology and introduces key clinical and biomedical measurements before introducing the key clinical studies and their influence in clinical practice which in turn flows into the needs and requirements around how biomedical engineering research can play a role in improving care. Given the significant clinical research to date and its impact on this complex area of care, this review thus provides a tutorial introduction around the review of the state of the art relevant to a biomedical engineering perspective. Discussion This review presents the significant clinical aspects and variables of ventilation management, the potential risks associated with suboptimal ventilation management, and a review of the major recent attempts to improve ventilation in the context of these variables. The unique aspect of this review is a focus on these key elements relevant to engineering new approaches. In particular, the need for ventilation strategies which consider, and directly account for, the significant differences in patient condition, disease etiology, and progression within patients is demonstrated with the subsequent requirement for optimal ventilation strategies to titrate for patient- and time-specific conditions. Conclusion Engineered, protective lung strategies that can directly account for and manage inter- and intra-patient variability thus offer great potential to improve both individual care, as well as cohort clinical outcomes.
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Affiliation(s)
- Vincent J Major
- Department of Population Health, NYU Langone Health, New York, NY, USA.
| | - Yeong Shiong Chiew
- School of Engineering, Monash University Malaysia, Subang Jaya, Malaysia
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
| | - J Geoffrey Chase
- Centre for Bioengineering, University of Canterbury, Christchurch, New Zealand
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23
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Morton SE, Dickson J, Chase JG, Docherty P, Desaive T, Howe SL, Shaw GM, Tawhai M. A virtual patient model for mechanical ventilation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2018; 165:77-87. [PMID: 30337083 DOI: 10.1016/j.cmpb.2018.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/24/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND OBJECTIVES Mechanical ventilation (MV) is a primary therapy for patients with acute respiratory failure. However, poorly selected ventilator settings can cause further lung damage due to heterogeneity of healthy and damaged alveoli. Varying positive-end-expiratory-pressure (PEEP) to a point of minimum elastance is a lung protective ventilator strategy. However, even low levels of PEEP can lead to ventilator induced lung injury for individuals with highly inflamed pulmonary tissue. Hence, models that could accurately predict peak inspiratory pressures after changes to PEEP could improve clinician confidence in attempting potentially beneficial treatment strategies. METHODS This study develops and validates a physiologically relevant respiratory model that captures elastance and resistance via basis functions within a well-validated single compartment lung model. The model can be personalised using information available at a low PEEP to predict lung mechanics at a higher PEEP. Proof of concept validation is undertaken with data from four patients and eight recruitment manoeuvre arms. RESULTS Results show low error when predicting upwards over the clinically relevant pressure range, with the model able to predict peak inspiratory pressure with less than 10% error over 90% of the range of PEEP changes up to 12 cmH2O. CONCLUSIONS The results provide an in-silico model-based means of predicting clinically relevant responses to changes in MV therapy, which is the foundation of a first virtual patient for MV.
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Affiliation(s)
- S E Morton
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - J Dickson
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - J G Chase
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - P Docherty
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - T Desaive
- GIGA Cardiovascular Science, University of Liege, Liege, Belgium.
| | - S L Howe
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - G M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand.
| | - M Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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24
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Abstract
Perioperative lung injury is a major source of postoperative morbidity, excess healthcare use, and avoidable mortality. Many potential inciting factors can lead to this condition, including intraoperative ventilator induced lung injury. Questions exist as to whether protective ventilation strategies used in the intensive care unit for patients with acute respiratory distress syndrome are equally beneficial for surgical patients, most of whom do not present with any pre-existing lung pathology. Studied both individually and in combination as a package of intraoperative lung protective ventilation, the use of low tidal volumes, moderate positive end expiratory pressure, and recruitment maneuvers have been shown to improve oxygenation and pulmonary physiology and to reduce postoperative pulmonary complications in at risk patient groups. Further work is needed to define the potential contributions of alternative ventilator strategies, limiting excessive intraoperative oxygen supplementation, use of non-invasive techniques in the postoperative period, and personalized mechanical ventilation. Although the weight of evidence strongly suggests a role for lung protective ventilation in moderate risk patient groups, definitive evidence of its benefit for the general surgical population does not exist. However, given the shift in understanding of what is needed for adequate oxygenation and ventilation under anesthesia, the largely historical arguments against the use of intraoperative lung protective ventilation may soon be outdated, on the basis of its expanding track record of safety and efficacy in multiple settings.
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Affiliation(s)
- Brian O'Gara
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Daniel Talmor
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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25
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Lung-thorax compliance measured during a spontaneous breathing trial is a good index of extubation failure in the surgical intensive care unit: a retrospective cohort study. J Intensive Care 2018; 6:44. [PMID: 30083347 PMCID: PMC6069862 DOI: 10.1186/s40560-018-0313-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/18/2018] [Indexed: 01/27/2023] Open
Abstract
Background Extubation failure is associated with mortality and morbidity in the intensive care unit. Ventilator weaning protocols have been introduced, and extubation is conducted based on the results of a spontaneous breathing trial. Room for improvement still exists in extubation management, and additional objective indices may improve the safety of the weaning and extubation process. Static lung-thorax compliance reflects lung expansion difficulty that is caused by several conditions, such as atelectasis, fibrosis, and pleural effusion. Nevertheless, it is not used commonly in the weaning and extubation process. In this study, we investigated whether lung-thorax compliance is a good index of extubation failure in adults even when patients pass a spontaneous breathing trial. Methods In a single-center, retrospective cohort study, patients over 18 years of age were mechanically ventilated, weaned with proportional assist ventilation, and underwent a spontaneous breathing trial process in surgical intensive care units of Kagawa University Hospital from July 2014 to June 2016. Extubation failure was the outcome measure of the study. We defined extubation failures as when patients were reintubated or underwent non-invasive positive-pressure ventilation within 24 h after extubation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the clinical involvement of several parameters. The area under the curve (AUC) was calculated to assess the discriminative power of the parameters. Results We analyzed 173 patients and compared the success and failure groups. Most patients (162, 93.6%) were extubated successfully, and extubation failed in 11 patients (6.4%). The averages of lung-thorax compliance values in the success and failure groups were 71.9 ± 23.0 and 43.3 ± 14.6 mL/cmH2O, respectively, and were significantly different (p < 0.0001). In the ROC curve analysis, the AUC was highest for lung-thorax compliance (0.862), followed by the respiratory rate (0.821), rapid shallow breathing index (0.781), Acute Physiology and Chronic Health Evaluation II score (0.72), heart rate (0.715), and tidal volume (0.695). Conclusions Lung-thorax compliance measured during a spontaneous breathing trial is a potential indicator of extubation failure in postoperative patients.
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De Monte V, Bufalari A, Grasso S, Ferrulli F, Crovace AM, Lacitignola L, Staffieri F. Respiratory effects of low versus high tidal volume with or without positive end-expiratory pressure in anesthetized dogs with healthy lungs. Am J Vet Res 2018; 79:496-504. [DOI: 10.2460/ajvr.79.5.496] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Grieco DL, Russo A, Romanò B, Anzellotti GM, Ciocchetti P, Torrini F, Barelli R, Eleuteri D, Perilli V, Dell'Anna AM, Bongiovanni F, Sollazzi L, Antonelli M. Lung volumes, respiratory mechanics and dynamic strain during general anaesthesia. Br J Anaesth 2018; 121:1156-1165. [PMID: 30336861 DOI: 10.1016/j.bja.2018.03.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/11/2018] [Accepted: 03/28/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Driving pressure (ΔP) represents tidal volume normalised to respiratory system compliance (CRS) and is a novel parameter to target ventilator settings. We conducted a study to determine whether CRS and ΔP reflect aerated lung volume and dynamic strain during general anaesthesia. METHODS Twenty non-obese patients undergoing open abdominal surgery received three PEEP levels (2, 7, or 12 cm H2O) in random order with constant tidal volume ventilation. Respiratory mechanics, lung volumes, and alveolar recruitment were measured to assess end-expiratory aerated volume, which was compared with the patient's individual predicted functional residual capacity in supine position (FRCp). RESULTS CRS was linearly related to aerated volume and ΔP to dynamic strain at PEEP of 2 cm H2O (intraoperative FRC) (r=0.72 and r=0.73, both P<0.001). These relationships were maintained with higher PEEP only when aerated volume did not overcome FRCp (r=0.73, P<0.001; r=0.54, P=0.004), with 100 ml lung volume increases accompanied by 1.8 ml cm H2O-1 (95% confidence interval [1.1-2.5]) increases in CRS. When aerated volume was greater or equal to FRCp (35% of patients at PEEP 2 cm H2O, 55% at PEEP 7 cm H2O, and 75% at PEEP 12 cm H2O), CRS and ΔP were independent from aerated volume and dynamic strain, with CRS weakly but significantly inversely related to alveolar dead space fraction (r=-0.47, P=0.001). PEEP-induced alveolar recruitment yielded higher CRS and reduced ΔP only at aerated volumes below FRCp (P=0.015 and 0.008, respectively). CONCLUSIONS During general anaesthesia, respiratory system compliance and driving pressure reflect aerated lung volume and dynamic strain, respectively, only if aerated volume does not exceed functional residual capacity in supine position, which is a frequent event when PEEP is used in this setting.
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Affiliation(s)
- D L Grieco
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy.
| | - A Russo
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - B Romanò
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - G M Anzellotti
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - P Ciocchetti
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - F Torrini
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - R Barelli
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - D Eleuteri
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - V Perilli
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - A M Dell'Anna
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - F Bongiovanni
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - L Sollazzi
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
| | - M Antonelli
- Department of Anesthesiology and Intensive Care Medicine, Catholic University of the Sacred Heart, Fondazione "Policlinico Universitario A. Gemelli", Rome, Italy
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Ganjifard M, Samii M, Kouzegaran S, Sabertanha A. The effect of positive end-expiratory pressure during anesthesia on arterial oxygen saturation after surgery in patient undergoing cesarean section. Eur J Transl Myol 2018; 28:7191. [PMID: 29686815 PMCID: PMC5895984 DOI: 10.4081/ejtm.2018.7191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/23/2017] [Indexed: 12/03/2022] Open
Abstract
One of the major complications of general anesthesia in the recovery room is arterial oxygen desaturation and hypoxemia. Positive end-expiratory pressure (PEEP) can improve arterial oxygen saturation by increasing FRC. This study aims to evaluate the effects of applying PEEP on arterial oxygen saturation and hemodynamic parameters in the patient undergoing cesarean section in VALIASR hospital. In this double blind clinical trial we randomly allocated 120 patients of class1 and 2 ASA scheduled to undergoing cesarean section into 3 group (in 40).Different levels of PEEP (0, 5 and 10 CmH2o) were applied to each group while zero PEEP was established as control. All other variables (anesthesia and surgery techniques) were the same for all patients SPO2, noninvasive mean arterial pressure and heart rate were measured before, during and after surgery (Recovery room). The comparison of noninvasive arterial blood pressure and heart rate during and after surgery did not show significant differences but mean o2 saturation in group B (5 cmH2o PEEP) and C (10 cm H2o PEEP) in PACU was higher than control group (98.30±0.93 and 98.50±0.90 as opposed to97.12±1.15 respectively) P<0.001. In light of results applying PEEP is effective in preventing desaturation after surgery and improving respiratory indexes without the significant hemodynamic changes, the result of using five cmH2o PEEP is more efficient and satisfying.
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Affiliation(s)
- Mahmood Ganjifard
- Department of Anesthesia, Emam Reza General Hospital, Birjand University of Medical Sciences, Birjand, Iran
| | - Masoumeh Samii
- Student of Anesthesia, Emam Reza General Hospital, Birjand University of Medical Sciences, Birjand, Ira
| | - Samaneh Kouzegaran
- Department of Pediatrics, Valiasr General Hospital, Birjand University of Medical Sciences, Birjand, Iran
| | - Amir Sabertanha
- Department of Anesthesia, Emam Reza General Hospital, Birjand University of Medical Sciences, Birjand, Iran
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Chiew YS, Pretty CG, Shaw GM, Chiew YW, Lambermont B, Desaive T, Chase JG. Feasibility of titrating PEEP to minimum elastance for mechanically ventilated patients. Pilot Feasibility Stud 2015; 1:9. [PMID: 28435689 PMCID: PMC5395899 DOI: 10.1186/s40814-015-0006-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/26/2015] [Indexed: 01/11/2023] Open
Abstract
Background Selecting positive end-expiratory pressure (PEEP) during mechanical ventilation is important, as it can influence disease progression and outcome of acute respiratory distress syndrome (ARDS) patients. However, there are no well-established methods for optimizing PEEP selection due to the heterogeneity of ARDS. This research investigates the viability of titrating PEEP to minimum elastance for mechanically ventilated ARDS patients. Methods Ten mechanically ventilated ARDS patients from the Christchurch Hospital Intensive Care Unit were included in this study. Each patient underwent a stepwise PEEP recruitment manoeuvre. Airway pressure and flow data were recorded using a pneumotachometer. Patient-specific respiratory elastance (Ers) and dynamic functional residual capacity (dFRC) at each PEEP level were calculated and compared. Optimal PEEP for each patient was identified by finding the minima of the PEEP-Ers profile. Results Median Ers and dFRC over all patients and PEEP values were 32.2 cmH2O/l [interquartile range (IQR) 25.0–45.9] and 0.42 l [IQR 0.11–0.87]. These wide ranges reflect patient heterogeneity and variable response to PEEP. The level of PEEP associated with minimum Ers corresponds to a high change of functional residual capacity, representing the balance between recruitment and minimizing the risk of overdistension. Conclusions Monitoring patient-specific Ers can provide clinical insight to patient-specific condition and response to PEEP settings. The level of PEEP associated with minimum-Ers can be identified for each patient using a stepwise PEEP recruitment manoeuvre. This ‘minimum elastance PEEP’ may represent a patient-specific optimal setting during mechanical ventilation. Trial registration Australian New Zealand Clinical Trials Registry: ACTRN12611001179921. Electronic supplementary material The online version of this article (doi:10.1186/s40814-015-0006-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yeong Shiong Chiew
- Department of Mechanical Engineering, University of Canterbury, Private Bag, 8140, Christchurch, New Zealand
| | - Christopher G Pretty
- Department of Mechanical Engineering, University of Canterbury, Private Bag, 8140, Christchurch, New Zealand
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
| | - Yeong Woei Chiew
- Western Medicine Division, Hospital Lam Hua EE, Pulau Penang, Malaysia
| | | | - Thomas Desaive
- GIGA Cardiovascular Science, University of Liege, Liege, Belgium
| | - J Geoffrey Chase
- Department of Mechanical Engineering, University of Canterbury, Private Bag, 8140, Christchurch, New Zealand
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Brochard L, Chen L, Goligher E. Optimum positive end-expiratory pressure 40 years later. Indian J Crit Care Med 2014; 18:494-6. [PMID: 25136186 PMCID: PMC4134621 DOI: 10.4103/0972-5229.138143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Laurent Brochard
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada ; Keenan Research Institute, and Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Lu Chen
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada ; Keenan Research Institute, and Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Ewan Goligher
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada ; Division of Respirology, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada
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Díaz-Alersi R, Navarro-Ramírez C. Presión positiva teleespiratoria alta o convencional en el síndrome de distrés respiratorio agudo. Med Intensiva 2014; 38:311-4. [DOI: 10.1016/j.medin.2013.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 09/18/2013] [Accepted: 09/27/2013] [Indexed: 10/26/2022]
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Krebs J, Tsagogiorgas C, Pelosi P, Rocco PRM, Hottenrott M, Sticht C, Yard B, Luecke T. Open lung approach with low tidal volume mechanical ventilation attenuates lung injury in rats with massive brain damage. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:R59. [PMID: 24693992 PMCID: PMC4056811 DOI: 10.1186/cc13813] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 03/25/2014] [Indexed: 12/18/2022]
Abstract
Introduction The ideal ventilation strategy for patients with massive brain damage requires better elucidation. We hypothesized that in the presence of massive brain injury, a ventilation strategy using low (6 milliliters per kilogram ideal body weight) tidal volume (VT) ventilation with open lung positive end-expiratory pressure (LVT/OLPEEP) set according to the minimal static elastance of the respiratory system, attenuates the impact of massive brain damage on gas-exchange, respiratory mechanics, lung histology and whole genome alterations compared with high (12 milliliters per kilogram ideal body weight) VT and low positive end-expiratory pressure ventilation (HVT/LPEEP). Methods In total, 28 adult male Wistar rats were randomly assigned to one of four groups: 1) no brain damage (NBD) with LVT/OLPEEP; 2) NBD with HVT/LPEEP; 3) brain damage (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. All animals were mechanically ventilated for six hours. Brain damage was induced by an inflated balloon catheter into the epidural space. Hemodynamics was recorded and blood gas analysis was performed hourly. At the end of the experiment, respiratory system mechanics and lung histology were analyzed. Genome wide gene expression profiling and subsequent confirmatory quantitative polymerase chain reaction (qPCR) for selected genes were performed. Results In NBD, both LVT/OLPEEP and HVT/LPEEP did not affect arterial blood gases, as well as whole genome expression changes and real-time qPCR. In BD, LVT/OLPEEP, compared to HVT/LPEEP, improved oxygenation, reduced lung damage according to histology, genome analysis and real-time qPCR with decreased interleukin 6 (IL-6), cytokine-induced neutrophil chemoattractant 1 (CINC)-1 and angiopoietin-4 expressions. LVT/OLPEEP compared to HVT/LPEEP improved overall survival. Conclusions In BD, LVT/OLPEEP minimizes lung morpho-functional changes and inflammation compared to HVT/LPEEP.
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Cortes GA, Marini JJ. Two steps forward in bedside monitoring of lung mechanics: transpulmonary pressure and lung volume. Crit Care 2013; 17:219. [PMID: 23509867 PMCID: PMC3672500 DOI: 10.1186/cc12528] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Carvalho AR, Bergamini BC, Carvalho NS, Cagido VR, Neto AC, Jandre FC, Zin WA, Giannella-Neto A. Volume-Independent Elastance. Anesth Analg 2013; 116:627-33. [DOI: 10.1213/ane.0b013e31824a95ca] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Walkey AJ, Wiener RS. Risk factors for underuse of lung-protective ventilation in acute lung injury. J Crit Care 2011; 27:323.e1-9. [PMID: 21855285 DOI: 10.1016/j.jcrc.2011.06.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/21/2011] [Accepted: 06/26/2011] [Indexed: 11/24/2022]
Abstract
PURPOSE We assessed factors associated with underuse of lung-protective ventilation (LPV) in patients with acute lung injury (ALI). METHODS A secondary analysis of Acute Respiratory Distress Syndrome Clinical Trials Network trial data, 1999 to 2005, was conducted. Tidal volumes recorded before trial randomization were analyzed to determine receipt of LPV (tidal volume ≤ 6.5 mL/kg of predicted body weight [PBW]). RESULTS Of 1385 participants, 430 (31.2%) received LPV. Average tidal volume was 7.65 ± 1.82 mL/kg PBW; measured tidal volumes were greater than "lung-protective" tidal volumes predicted by 6.5 mL/kg PBW (mean difference, 67 ± 108 mL; P < .0001). Multivariate predictors of LPV underuse were older age (odds ratio [OR] per SD year, 1.18; 95% confidence interval [CI], 1.02-1.38), white race (OR, 1.40; 95% CI, 1.05-1.88), shorter stature (OR per SD centimeter, 0.55; 95% CI, 0.48-0.63), lower Simplified Acute Physiology II Score (OR per SD, 0.78; 95% CI, 0.67-0.92), lower lung injury score (OR per SD, 0.83; 95% CI, 0.70-0.95), decreased serum bicarbonate (OR per SD mmol/L, 0.83; 95% CI, 0.71-0.97), shorter preenrollment intensive care unit stay (OR per SD day, 0.84; 95% CI, 0.73-0.98), and use of non-volume-controlled ventilation (OR, 3.07; 95% CI, 1.78-5.27). Setting tidal volumes to 450 mL (men) or 350 mL (women) would provide LPV to 80% of patients with ALI. CONCLUSIONS Simple interventions could substantially improve adherence with LPV among patients with ALI and warrant prospective study.
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Affiliation(s)
- Allan J Walkey
- Boston University School of Medicine, The Pulmonary Center, Boston, MA 02118, USA.
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Ferreira HC, Mazzoli-Rocha F, Momesso DP, Garcia CSNB, Carvalho GMC, Lassance-Soares RM, Prota LFM, Morales MM, Faffe DS, Carvalho AR, Rocco PRM, Zin WA. On the crucial ventilatory setting adjustment from two- to one-lung ventilation. Respir Physiol Neurobiol 2011; 179:198-204. [PMID: 21871975 DOI: 10.1016/j.resp.2011.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/10/2011] [Accepted: 08/12/2011] [Indexed: 11/28/2022]
Abstract
Lung mechanics, histology, oxygenation and type-III procollagen (PCIII) mRNA were studied aiming to evaluate the need to readjust ventilatory pattern when going from two- to one-lung ventilation (OLV). Wistar rats were assigned to three groups: the left lung was not ventilated while the right lung received: (1) tidal volume (V(T))=5 ml/kg and positive end-expiratory pressure (PEEP)=2 cm H(2)O (V5P2), (2) V(T)=10 ml/kg and PEEP=2 cm H(2)O (V10P2), and (3) V(T)=5 ml/kg and PEEP=5 cm H(2)O (V5P5). At 1-h ventilation, V5P2 showed hypoxemia, alveolar collapse and impaired lung function. Higher PEEP minimized these changes and prevented hypoxemia. Although high V(T) prevented hypoxemia and maintained a higher specific compliance than V5P2, a morphologically inhomogeneous parenchyma and higher PCIII expression resulted. In conclusion, the association of low V(T) and an adequate PEEP level could be useful to maintain arterial oxygenation without inducing a possible inflammatory/remodeling response.
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Affiliation(s)
- Halina C Ferreira
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, RJ, Brazil.
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Recruitability, recruitment, and tidal volume interactions: Is biologically variable ventilation a possible answer?*. Crit Care Med 2011; 39:1839-40. [DOI: 10.1097/ccm.0b013e31821b82dd] [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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Ahmed F, Shafeeq AM, Moiz JA, Geelani MA. Comparison of effects of manual versus ventilator hyperinflation on respiratory compliance and arterial blood gases in patients undergoing mitral valve replacement. Heart Lung 2010; 39:437-43. [DOI: 10.1016/j.hrtlng.2009.10.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 10/01/2009] [Accepted: 10/09/2009] [Indexed: 11/28/2022]
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Brower RG, Brochard LJ. Lung-protective mechanical ventilation strategy for acute lung injury and acute respiratory distress syndrome. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/17471060600580722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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McCarren B, Chow CM. Description of manual hyperinflation in intubated patients with atelectasis. Physiother Theory Pract 2009. [DOI: 10.3109/09593989809057166] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Key Questions in Ventilator Management of the Burn-Injured Patient (First of Two Parts). J Burn Care Res 2009; 30:128-38. [DOI: 10.1097/bcr.0b013e318191fe44] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Davis JL, Morris A, Kallet RH, Powell K, Chi AS, Bensley M, Luce JM, Huang L. Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury. Thorax 2008; 63:988-93. [PMID: 18535118 DOI: 10.1136/thx.2008.095786] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Respiratory failure remains the leading indication for admission to the intensive care unit (ICU) and a leading cause of death for HIV-infected patients in spite of overall improvements in ICU mortality. It is unclear if these improvements are due to combination anti-retroviral therapy, low tidal volume ventilation for acute lung injury, or both. A study was undertaken to identify therapies and clinical factors associated with mortality in acute lung injury among HIV-infected patients with respiratory failure in the period 1996-2004. A secondary aim was to compare mortality before and after introduction of a low tidal volume ventilation protocol in 2000. METHODS A retrospective cohort study was performed of 148 consecutive HIV-infected adults admitted to the ICU at San Francisco General Hospital with acute lung injury requiring mechanical ventilation. Demographic and clinical information including data on mechanical ventilation was abstracted from medical records and analysed by multivariate analysis using logistic regression. RESULTS In-hospital mortality was similar before and after introduction of a low tidal volume ventilation protocol, although the study was not powered to exclude a clinically significant difference (risk difference -5.4%, 95% CI -21% to 11%, p = 0.51). Combination antiretroviral therapy was not clearly associated with mortality, except in patients with Pneumocystis pneumonia. Among all those with acute lung injury, lower tidal volume was associated with decreased mortality (adjusted odds ratio 0.76 per 1 ml/kg decrease, 95% CI 0.58 to 0.99, p = 0.043), after controlling for Pneumocystis pneumonia, serum albumin, illness severity, gas exchange impairment and plateau pressure. CONCLUSIONS Lower tidal volume ventilation is independently associated with reduced mortality in HIV-infected patients with acute lung injury and respiratory failure.
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Affiliation(s)
- J L Davis
- Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, California 94110, USA.
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Checkley W, Brower R, Korpak A, Thompson BT. Effects of a clinical trial on mechanical ventilation practices in patients with acute lung injury. Am J Respir Crit Care Med 2008; 177:1215-22. [PMID: 18356562 PMCID: PMC2408439 DOI: 10.1164/rccm.200709-1424oc] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 03/13/2008] [Indexed: 01/25/2023] Open
Abstract
RATIONALE In a clinical trial by the Acute Respiratory Distress Syndrome Network (ARDSNet), mechanical ventilation with tidal volumes of 6 ml/kg decreased mortality from acute lung injury. However, interpretations of these results generated controversy and it was unclear if this trial would change usual-care practices. OBJECTIVES First, to determine if clinical practices at ARDSNet hospitals changed after the tidal volume trial. Second, to determine if tidal volume and plateau pressure (Pplat) within 48 hours before randomization affected hospital mortality in patients subsequently managed with 6 ml/kg predicted body weight (PBW). METHODS We used preenrollment data from 2,451 patients enrolled in six trials (1996-2005) to describe changes in tidal volume over time. We used logistic regression to determine if preenrollment tidal volume or Pplat affected mortality. MEASUREMENTS AND MAIN RESULTS Median preenrollment tidal volume decreased from 10.3 ml/kg PBW (range, 4.3-17.1) during the tidal volume trial (1996-1999) to 7.3 ml/kg PBW (range, 3.9-16.2) after its completion (P < 0.001). Preenrollment tidal volume was not associated with mortality (P = 0.566). The odds of death increased multiplicatively with each cm H(2)O of preenrollment Pplat (P < 0.001) (e.g., the odds of death was 1.37 times greater when preenrollment Pplat increased by 10 cm H(2)O). CONCLUSIONS Physicians used lower tidal volumes after publication of the tidal volume trial. Preenrollment Pplat was strongly associated with mortality, and may reflect disease severity independent of tidal volume. Pplat measured early in the course of acute lung injury, after accounting for tidal volume, is a respiratory system-specific value with strong prognostic significance.
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Affiliation(s)
- William Checkley
- Division of Pulmonary and Critical Care, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA.
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Carvalho ARS, Jandre FC, Pino AV, Bozza FA, Salluh J, Rodrigues R, Ascoli FO, Giannella-Neto A. Positive end-expiratory pressure at minimal respiratory elastance represents the best compromise between mechanical stress and lung aeration in oleic acid induced lung injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 11:R86. [PMID: 17688701 PMCID: PMC2206498 DOI: 10.1186/cc6093] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 04/03/2007] [Accepted: 08/09/2007] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Protective ventilatory strategies have been applied to prevent ventilator-induced lung injury in patients with acute lung injury (ALI). However, adjustment of positive end-expiratory pressure (PEEP) to avoid alveolar de-recruitment and hyperinflation remains difficult. An alternative is to set the PEEP based on minimizing respiratory system elastance (Ers) by titrating PEEP. In the present study we evaluate the distribution of lung aeration (assessed using computed tomography scanning) and the behaviour of Ers in a porcine model of ALI, during a descending PEEP titration manoeuvre with a protective low tidal volume. METHODS PEEP titration (from 26 to 0 cmH2O, with a tidal volume of 6 to 7 ml/kg) was performed, following a recruitment manoeuvre. At each PEEP, helical computed tomography scans of juxta-diaphragmatic parts of the lower lobes were obtained during end-expiratory and end-inspiratory pauses in six piglets with ALI induced by oleic acid. The distribution of the lung compartments (hyperinflated, normally aerated, poorly aerated and non-aerated areas) was determined and the Ers was estimated on a breath-by-breath basis from the equation of motion of the respiratory system using the least-squares method. RESULTS Progressive reduction in PEEP from 26 cmH2O to the PEEP at which the minimum Ers was observed improved poorly aerated areas, with a proportional reduction in hyperinflated areas. Also, the distribution of normally aerated areas remained steady over this interval, with no changes in non-aerated areas. The PEEP at which minimal Ers occurred corresponded to the greatest amount of normally aerated areas, with lesser hyperinflated, and poorly and non-aerated areas. Levels of PEEP below that at which minimal Ers was observed increased poorly and non-aerated areas, with concomitant reductions in normally inflated and hyperinflated areas. CONCLUSION The PEEP at which minimal Ers occurred, obtained by descending PEEP titration with a protective low tidal volume, corresponded to the greatest amount of normally aerated areas, with lesser collapsed and hyperinflated areas. The institution of high levels of PEEP reduced poorly aerated areas but enlarged hyperinflated ones. Reduction in PEEP consistently enhanced poorly or non-aerated areas as well as tidal re-aeration. Hence, monitoring respiratory mechanics during a PEEP titration procedure may be a useful adjunct to optimize lung aeration.
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Affiliation(s)
- Alysson Roncally S Carvalho
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horácio Macedo, CT Bloco H-327, 2030, 21941-914, Rio de Janeiro, Brazil
| | - Frederico C Jandre
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horácio Macedo, CT Bloco H-327, 2030, 21941-914, Rio de Janeiro, Brazil
| | - Alexandre V Pino
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horácio Macedo, CT Bloco H-327, 2030, 21941-914, Rio de Janeiro, Brazil
| | - Fernando A Bozza
- Fundação Oswaldo Cruz, Instituto de Pesquisa Clinica Evandro Chagas e Laboratório de Imunofarmacologia, IOC, Av Brasil, 4365, Manguinhos, 21045-900 Rio de Janeiro, Brazil
| | - Jorge Salluh
- National Institute of Cancer-1, ICU, Praça Cruz Vermelha, 20230-130 Rio de Janeiro, Brazil
| | - Rosana Rodrigues
- Radiodiagnostic Service, Clementino Fraga Filho Hospital, Federal University of Rio de Janeiro, R Professor Rodolpho Paulo Rocco, 255, 21-941-913 Rio de Janeiro, Brazil
| | - Fabio O Ascoli
- Fundação Oswaldo Cruz, Instituto de Pesquisa Clinica Evandro Chagas e Laboratório de Imunofarmacologia, IOC, Av Brasil, 4365, Manguinhos, 21045-900 Rio de Janeiro, Brazil
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Jandre FC, Modesto FC, Carvalho ARS, Giannella-Neto A. The endotracheal tube biases the estimates of pulmonary recruitment and overdistension. Med Biol Eng Comput 2007; 46:69-73. [DOI: 10.1007/s11517-007-0227-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 07/01/2007] [Indexed: 11/27/2022]
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Leong LMC, Chatterjee S, Gao F. The effect of positive end expiratory pressure on the respiratory profile during one-lung ventilation for thoracotomy. Anaesthesia 2007; 62:23-6. [PMID: 17156223 DOI: 10.1111/j.1365-2044.2006.04893.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Summary In this randomised controlled trial we examined the effects of four different levels of positive end expiratory pressure (PEEP at 0, 5, 8 or 10 cmH(2)O), added to the dependent lung, on respiratory profile and oxygenation during one lung ventilation. Forty-six patients were recruited to receive one of the randomised PEEP levels during one lung ventilation. We did not find significant differences in lung compliance, intra-operative or postoperative oxygenation amongst the four different groups. However, the physiological deadspace to tidal volume ventilation ratio was significantly lower in the 8 cmH(2)O PEEP group compared with the other levels of PEEP (p < 0.0001). We concluded that the use of PEEP (< or =10 cmH(2)O) during one lung ventilation does not clinically improve lung compliance, intra-operative or postoperative oxygenation despite a statistically significant reduction in the physiological deadspace to tidal volume ratio.
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Affiliation(s)
- L M C Leong
- Department of Anaesthesia, Alexandra Hospital, Redditch B98 7UB, UK.
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Abstract
Monitoring the mechanical properties (both static and dynamic) of the respiratory tract is essential for the diagnosis and prognosis of the disease causing any condition and to take the pertinent therapeutic decisions. These measurements can maintain a lung function in optimum conditions during mechanical ventilation and choose the best time to disconnect the patient. Until recently, monitoring the respiration of patients undergoing mechanical ventilation required sophisticated and complicated apparatuses or difficult techniques. Instrumentalization of the respiratory as a monitor has evolved in such a way that many respirators can graphically reproduce in real time the changes that occur in some variables of the respiratory cycle. Using these monitoring techniques improves knowledge of lung behavior of each patient with ARDS, thus facilitating its management. It may also improve decision-making in each individual patient, improving their prognosis.
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Affiliation(s)
- M Pérez
- Servicio de Cuidados Intensivos, Fundación Jiménez Díaz, Madrid, España.
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Carvalho ARS, Jandre FC, Pino AV, Bozza FA, Salluh JI, Rodrigues RS, Soares JHN, Giannella-Neto A. Effects of descending positive end-expiratory pressure on lung mechanics and aeration in healthy anaesthetized piglets. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2006; 10:R122. [PMID: 16925814 PMCID: PMC1750982 DOI: 10.1186/cc5030] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 08/22/2006] [Indexed: 12/03/2022]
Abstract
Introduction Atelectasis and distal airway closure are common clinical entities of general anaesthesia. These two phenomena are expected to reduce the ventilation of dependent lung regions and represent major causes of arterial oxygenation impairment in anaesthetic conditions. The behaviour of the elastance of the respiratory system (Ers), as well as the lung aeration assessed by computed tomography (CT) scan, was evaluated during a descendent positive end-expiratory pressure (PEEP) titration. This work sought to evaluate the potential usefulness of Ers monitoring to set the PEEP in order to prevent tidal recruitment and hyperinflation of healthy lungs under general anaesthesia. Methods PEEP titration (from 16 to 0 cmH2O, tidal volume of 8 ml/kg) was performed, and at each PEEP, CT scans were obtained during end-expiratory and end-inspiratory pauses in six healthy, anaesthetized and paralyzed piglets. The distribution of lung aeration was determined and the tidal re-aeration was calculated as the difference between end-expiratory and end-inspiratory poorly aerated and normally aerated areas. Similarly, tidal hyperinflation was obtained as the difference between end-inspiratory and end-expiratory hyperinflated areas. Ers was estimated from the equation of motion of the respiratory system during all PEEP titration with the least-squares method. Results Hyperinflated areas decreased from PEEP 16 to 0 cmH2O (ranges decreased from 24–62% to 1–7% at end-expiratory pauses and from 44–73% to 4–17% at end-inspiratory pauses) whereas normally aerated areas increased (from 30–66% to 72–83% at end-expiratory pauses and from 19–48% to 73–77% at end-inspiratory pauses). From 16 to 8 cmH2O, Ers decreased with a corresponding reduction in tidal hyperinflation. A flat minimum of Ers was observed from 8 to 4 cmH2O. For PEEP below 4 cmH2O, Ers increased in association with a rise in tidal re-aeration and a flat maximum of the normally aerated areas. Conclusion In healthy piglets under a descending PEEP protocol, the PEEP at minimum Ers presented a compromise between maximizing normally aerated areas and minimizing tidal re-aeration and hyperinflation. High levels of PEEP, greater than 8 cmH2O, reduced tidal re-aeration but increased hyperinflation with a concomitant decrease in normally aerated areas.
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Affiliation(s)
- Alysson Roncally S Carvalho
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68510, 21945-970, Rio de Janeiro, RJ, Brazil
| | - Frederico C Jandre
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68510, 21945-970, Rio de Janeiro, RJ, Brazil
| | - Alexandre V Pino
- Electronic Engineering Department, Catholic University of Pelotas, Rua Félix da Cunha 412, 96010-000, Pelotas, RS, Brazil
| | - Fernando A Bozza
- Clementino Fraga Filho Hospital, ICU, Federal University of Rio de Janeiro, Av. Brigadeiro Trompowsky, s/n°, 21950-900, Rio de Janeiro, RJ, Brazil
| | - Jorge I Salluh
- National Institute of Cancer – 1, ICU, Praça Cruz Vermelha 23, 20230-130, Rio de Janeiro, RJ, Brazil
| | - Rosana S Rodrigues
- Clementino Fraga Filho Hospital, Radiodiagnostic Service, Federal University of Rio de Janeiro, Av. Brigadeiro Trompowsky, s/n°, 21950-900, Rio de Janeiro, RJ, Brazil
| | - João HN Soares
- UNIGRANRIO, School of Veterinary Medicine, Rua Professor José de Sousa Herdy 1160, 25071-200, Duque de Caxias, RJ, Brazil
| | - Antonio Giannella-Neto
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68510, 21945-970, Rio de Janeiro, RJ, Brazil
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