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American Journal of Respiratory and... Feb 2017Mechanical ventilation is used to sustain life in patients with acute respiratory failure. A major concern in mechanically ventilated patients is the risk of...
Mechanical ventilation is used to sustain life in patients with acute respiratory failure. A major concern in mechanically ventilated patients is the risk of ventilator-induced lung injury, which is partially prevented by lung-protective ventilation. Spontaneously breathing, nonintubated patients with acute respiratory failure may have a high respiratory drive and breathe with large tidal volumes and potentially injurious transpulmonary pressure swings. In patients with existing lung injury, regional forces generated by the respiratory muscles may lead to injurious effects on a regional level. In addition, the increase in transmural pulmonary vascular pressure swings caused by inspiratory effort may worsen vascular leakage. Recent data suggest that these patients may develop lung injury that is similar to the ventilator-induced lung injury observed in mechanically ventilated patients. As such, we argue that application of a lung-protective ventilation, today best applied with sedation and endotracheal intubation, might be considered a prophylactic therapy, rather than just a supportive therapy, to minimize the progression of lung injury from a form of patient self-inflicted lung injury. This has important implications for the management of these patients.
Topics: Disease Progression; Humans; Respiration, Artificial; Respiratory Distress Syndrome; Ventilator-Induced Lung Injury
PubMed: 27626833
DOI: 10.1164/rccm.201605-1081CP -
Annals of the American Thoracic Society Feb 2018The primary purpose of mechanical ventilation is to decrease work of breathing. Achieving this goal requires that cycling of the ventilator be carefully aligned with the...
The primary purpose of mechanical ventilation is to decrease work of breathing. Achieving this goal requires that cycling of the ventilator be carefully aligned with the intrinsic rhythm of a patient's respiratory center output. Problems arise at the point of ventilator triggering, post-trigger inflation, and inspiration-expiration switchover. Careful, iterative adjustments of ventilator settings are required to minimize work of breathing. Use of protocols for the selection of ventilator settings can lead to complications (including alveolar overdistention) and risk of death. Because complications are axiomatic to mechanical ventilation, it should be discontinued at the earliest possible time. To shorten ventilator time, the critical step is to screen for weanability through use of weaning predictor tests. Use of T-tube trials circumvents the impossibility of estimating patient work of breathing during pressure support. Before extubation, patients should demonstrate the ability to breathe successfully in the absence of pressure support and positive end-expiratory pressure.
Topics: Humans; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Mechanics; Respiratory Muscles; Ventilator Weaning; Work of Breathing
PubMed: 29461885
DOI: 10.1513/AnnalsATS.201705-417KV -
Intensive & Critical Care Nursing Aug 2015Identification and adoption of strategies to promote timely and successful weaning from mechanical ventilation remain a research and quality improvement priority. The... (Review)
Review
Identification and adoption of strategies to promote timely and successful weaning from mechanical ventilation remain a research and quality improvement priority. The most important steps in the weaning process to prevent unnecessary prolongation of mechanical ventilation are timely recognition of both readiness to wean and readiness to extubate. Strategies shown to be effective in promoting timely weaning include weaning protocols and use of spontaneous breathing trials. This review explores various other strategies that also may promote timely and successful weaning including bundling of spontaneous breathing trials with sedation and delirium monitoring/management as well as early mobility, the use of automated weaning systems and modes that improve patient-ventilator interaction, mechanical insufflation-exsufflation as a weaning adjunct, early extubation to non-invasive ventilation and high flow humidified oxygen. As most critically ill patients requiring mechanical ventilation will tolerate extubation with minimal weaning, identification of strategies to improve management of those patients experiencing difficult and prolonged weaning should be a priority for clinical practice, quality improvement initiatives and weaning research.
Topics: Airway Extubation; Clinical Protocols; Humans; Noninvasive Ventilation; Respiration, Artificial; Ventilator Weaning
PubMed: 26209016
DOI: 10.1016/j.iccn.2015.07.003 -
Anesthesia and Analgesia Feb 2024Mechanical ventilation (MV) has played a crucial role in the medical field, particularly in anesthesia and in critical care medicine (CCM) settings. MV has evolved...
Mechanical ventilation (MV) has played a crucial role in the medical field, particularly in anesthesia and in critical care medicine (CCM) settings. MV has evolved significantly since its inception over 70 years ago and the future promises even more advanced technology. In the past, ventilation was provided manually, intermittently, and it was primarily used for resuscitation or as a last resort for patients with severe respiratory or cardiovascular failure. The earliest MV machines for prolonged ventilatory support and oxygenation were large and cumbersome. They required a significant amount of skills and expertise to operate. These early devices had limited capabilities, battery, power, safety features, alarms, and therefore these often caused harm to patients. Moreover, the physiology of MV was modified when mechanical ventilators moved from negative pressure to positive pressure mechanisms. Monitoring systems were also very limited and therefore the risks related to MV support were difficult to quantify, predict and timely detect for individual patients who were necessarily young with few comorbidities. Technology and devices designed to use tracheostomies versus endotracheal intubation evolved in the last century too and these are currently much more reliable. In the present, positive pressure MV is more sophisticated and widely used for extensive period of time. Modern ventilators use mostly positive pressure systems and are much smaller, more portable than their predecessors, and they are much easier to operate. They can also be programmed to provide different levels of support based on evolving physiological concepts allowing lung-protective ventilation. Monitoring systems are more sophisticated and knowledge related to the physiology of MV is improved. Patients are also more complex and elderly compared to the past. MV experts are informed about risks related to prolonged or aggressive ventilation modalities and settings. One of the most significant advances in MV has been protective lung ventilation, diaphragm protective ventilation including noninvasive ventilation (NIV). Health care professionals are familiar with the use of MV and in many countries, respiratory therapists have been trained for the exclusive purpose of providing safe and professional respiratory support to critically ill patients. Analgo-sedation drugs and techniques are improved, and more sedative drugs are available and this has an impact on recovery, weaning, and overall patients' outcome. Looking toward the future, MV is likely to continue to evolve and improve alongside monitoring techniques and sedatives. There is increasing precision in monitoring global "patient-ventilator" interactions: structure and analysis (asynchrony, desynchrony, etc). One area of development is the use of artificial intelligence (AI) in ventilator technology. AI can be used to monitor patients in real-time, and it can predict when a patient is likely to experience respiratory distress. This allows medical professionals to intervene before a crisis occurs, improving patient outcomes and reducing the need for emergency intervention. This specific area of development is intended as "personalized ventilation." It involves tailoring the ventilator settings to the individual patient, based on their physiology and the specific condition they are being treated for. This approach has the potential to improve patient outcomes by optimizing ventilation and reducing the risk of harm. In conclusion, MV has come a long way since its inception, and it continues to play a critical role in anesthesia and in CCM settings. Advances in technology have made MV safer, more effective, affordable, and more widely available. As technology continues to improve, more advanced and personalized MV will become available, leading to better patients' outcomes and quality of life for those in need.
Topics: Humans; Aged; Respiration, Artificial; Ventilator Weaning; Artificial Intelligence; Quality of Life; Positive-Pressure Respiration
PubMed: 38215710
DOI: 10.1213/ANE.0000000000006701 -
Swiss Medical Weekly 2017Critically ill patients with the need for mechanical ventilation show complex interactions between respiratory and cardiovascular physiology. These interactions are... (Review)
Review
Critically ill patients with the need for mechanical ventilation show complex interactions between respiratory and cardiovascular physiology. These interactions are important as they may guide the clinician's therapeutic decisions and, possibly, affect patient outcome. The aim of the present review is to provide the practicing physician with an overview of the concepts of heart-lung interactions during mechanical ventilation. We outline the basic cardiac and respiratory physiology during spontaneous breathing and under mechanical ventilation. The main focus is on the interaction between positive pressure ventilation and its effects on right and left ventricular pre- and afterload and ventricular interdependence. Further we discuss different modalities to assess volume responsiveness, such as pulse pressure variation. We aim to familiarise the reader with cardiovascular side effects of mechanical ventilation when experiencing weaning problems or right heart failure.
Topics: Blood Pressure; Cardiovascular System; Heart; Heart Rate; Hemodynamics; Humans; Lung; Respiration, Artificial
PubMed: 28944931
DOI: 10.4414/smw.2017.14491 -
Journal of Critical Care Apr 2022To compare neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV), adaptive support ventilation (ASV) and Smartcare pressure support... (Meta-Analysis)
Meta-Analysis Review
Comparison of advanced closed-loop ventilation modes with pressure support ventilation for weaning from mechanical ventilation in adults: A systematic review and meta-analysis.
PURPOSE
To compare neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV), adaptive support ventilation (ASV) and Smartcare pressure support (Smartcare/PS) with standard pressure support ventilation (PSV) regarding their effectiveness for weaning critically ill adults from invasive mechanical ventilation (IMV).
METHODS
Electronic databases were searched to identify parallel-group randomized controlled trials (RCTs) comparing NAVA, PAV, ASV, or Smartcare/PS with PSV, in adult patients under IMV through July 28, 2021. Primary outcome was weaning success. Secondary outcomes included weaning time, total MV duration, reintubation or use of non-invasive MV (NIMV) within 48 h after extubation, in-hospital and intensive care unit (ICU) mortality, in-hospital and ICU length of stay (LOS) (PROSPERO registration No:CRD42021270299).
RESULTS
Twenty RCTs were finally included. Compared to PSV, NAVA was associated with significantly lower risk for in-hospital and ICU death and lower requirements for post-extubation NIMV. Moreover, PAV showed significant advantage over PSV in terms of weaning rates, MV duration and ICU LOS. No significant differences were found between ASV or Smart care/PS and PSV.
CONCLUSIONS
Moderate certainty evidence suggest that PAV increases weaning success rates, shortens MV duration and ICU LOS compared to PSV. It is also noteworthy that NAVA seems to improve in-hospital and ICU survival.
Topics: Adult; Humans; Intensive Care Units; Interactive Ventilatory Support; Positive-Pressure Respiration; Respiration, Artificial; Ventilator Weaning
PubMed: 34839229
DOI: 10.1016/j.jcrc.2021.11.010 -
Anesthesiology Sep 2015Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective... (Review)
Review
Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers.
Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials.
Topics: Animals; Humans; Intraoperative Care; Lung; Positive-Pressure Respiration; Postoperative Complications; Respiration, Artificial; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 26120769
DOI: 10.1097/ALN.0000000000000754 -
Current Opinion in Critical Care Feb 2019Diaphragm dysfunction is common in mechanically ventilated patients and predisposes them to prolonged ventilator dependence and poor clinical outcomes. Mechanical... (Review)
Review
PURPOSE OF REVIEW
Diaphragm dysfunction is common in mechanically ventilated patients and predisposes them to prolonged ventilator dependence and poor clinical outcomes. Mechanical ventilation is a major cause of diaphragm dysfunction in these patients, raising the possibility that diaphragm dysfunction might be prevented if mechanical ventilation can be optimized to avoid diaphragm injury - a concept referred to as diaphragm-protective ventilation. This review surveys the evidence supporting the concept of diaphragm-protective ventilation and introduces potential routes and challenges to pursuing this strategy.
RECENT FINDINGS
Mechanical ventilation can cause diaphragm injury (myotrauma) by a variety of mechanisms. An understanding of these various mechanisms raises the possibility of a new approach to ventilatory management, a diaphragm-protective ventilation strategy. Deranged inspiratory effort is the main mediator of diaphragmatic myotrauma; titrating ventilation to maintain an optimal level of inspiratory effort may help to limit diaphragm dysfunction and accelerate liberation of mechanical ventilation.
SUMMARY
Mechanical ventilation can cause diaphragm injury and weakness. A novel diaphragm-protective ventilation strategy, avoiding the harmful effects of both excessive and insufficient inspiratory effort, has the potential to substantially improve outcomes for patients.
Topics: Diaphragm; Humans; Lung; Respiration; Respiration, Artificial
PubMed: 30531536
DOI: 10.1097/MCC.0000000000000578 -
American Journal of Respiratory and... May 2015Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced...
Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure.
Topics: Acute Lung Injury; Animal Experimentation; Animals; Critical Care; Forecasting; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; Humans; Poliomyelitis; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Resuscitation; Tracheotomy
PubMed: 25844759
DOI: 10.1164/rccm.201503-0421PP -
Emergency Medicine Clinics of North... Aug 2022This article explains the physiologic basis and fundamentals behind the technology of continuous positive airway pressure, bilevel positive airway pressure, and high... (Review)
Review
This article explains the physiologic basis and fundamentals behind the technology of continuous positive airway pressure, bilevel positive airway pressure, and high flow nasal canula. Additionally, it explores some of the core literature behind their clinical applications. It will also compare HFNC with other noninvasive modalities for respiratory failure alongside clinical titration and weaning algorithms in the emergency department setting.
Topics: Cannula; Continuous Positive Airway Pressure; Humans; Noninvasive Ventilation; Oxygen Inhalation Therapy; Respiration, Artificial; Respiratory Insufficiency
PubMed: 35953219
DOI: 10.1016/j.emc.2022.05.010