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The American Journal of the Medical... Dec 2021Mechanical ventilation is a potentially life-saving therapy for patients with acute lung injury, but the ventilator itself may cause lung injury. Ventilator-induced lung... (Review)
Review
Mechanical ventilation is a potentially life-saving therapy for patients with acute lung injury, but the ventilator itself may cause lung injury. Ventilator-induced lung injury (VILI) is sometimes an unfortunate consequence of mechanical ventilation. It is not clear however how best to minimize VILI through adjustment of various parameters including tidal volume, plateau pressure, driving pressure, and positive end expiratory pressure (PEEP). No single parameter provides a clear indication for onset of lung injury attributable exclusively to the ventilator. There is currently interest in quantifying how static and dynamic parameters contribute to VILI. One concept that has emerged is the consideration of the amount of energy transferred from the ventilator to the respiratory system per unit time, which can be quantified as mechanical power. This review article reports on recent literature in this emerging field and future roles for mechanical power assessments in prospective studies.
Topics: Humans; Prospective Studies; Respiration, Artificial; Respiratory Distress Syndrome; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 34597688
DOI: 10.1016/j.amjms.2021.09.004 -
Journal of Intensive Care Medicine Nov 2022Since the inception of critical care medicine and artificial ventilation, literature and research on weaning has transformed daily patient care in intensive care units... (Review)
Review
Since the inception of critical care medicine and artificial ventilation, literature and research on weaning has transformed daily patient care in intensive care units (ICU). As our knowledge of mechanical ventilation (MV) improved, so did the need to study patient-ventilator interactions and weaning predictors. Randomized trials have evaluated the use of protocol-based weaning (vs. usual care) to study the duration of MV in ICUs, different techniques to conduct spontaneous breathing trials (SBT), and strategies to eventually extubate a patient whose initial SBT failed. Despite considerable milestones in the management of multiple diseases contributing to reversible respiratory failure, in the application of early rehabilitative interventions to preserve muscle integrity, and in ventilator technology that mitigates against ventilator injury and dyssynchrony, major barriers to successful liberation from MV persist. This review provides a broad encompassing view of weaning classification, causes of weaning failure, and evidence behind weaning predictors and weaning modes.
Topics: Humans; Intensive Care Units; Respiration, Artificial; Respiratory Insufficiency; Ventilator Weaning; Ventilators, Mechanical
PubMed: 35815895
DOI: 10.1177/08850666221095436 -
The American Journal of the Medical... Jul 2021Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with a variety of disease processes that lead to acute lung... (Review)
Review
Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with a variety of disease processes that lead to acute lung injury with increased non-hydrostatic extravascular lung water, reduced compliance, and severe hypoxemia. Despite significant advances, mortality associated with this syndrome remains high. Mechanical ventilation remains the most important aspect of managing patients with ARDS. An in-depth knowledge of lung protective ventilation, optimal PEEP strategies, modes of ventilation and recruitment maneuvers are essential for ventilatory management of ARDS. Although, the management of ARDS is constantly evolving as new studies are published and guidelines being updated; we present a detailed review of the literature including the most up-to-date studies and guidelines in the management of ARDS. We believe this review is particularly helpful in the current times where more than half of the acute care hospitals lack in-house intensivists and the burden of ARDS is at large.
Topics: Disease Management; Extracorporeal Membrane Oxygenation; Humans; Positive-Pressure Respiration; Practice Guidelines as Topic; Respiration, Artificial; Respiratory Distress Syndrome
PubMed: 34090669
DOI: 10.1016/j.amjms.2020.12.019 -
Intensive Care Medicine Dec 2020Obesity is an important risk factor for major complications, morbidity and mortality related to intubation procedures and ventilation in the intensive care unit (ICU).... (Review)
Review
Obesity is an important risk factor for major complications, morbidity and mortality related to intubation procedures and ventilation in the intensive care unit (ICU). The fall in functional residual capacity promotes airway closure and atelectasis formation. This narrative review presents the impact of obesity on the respiratory system and the key points to optimize airway management, noninvasive and invasive mechanical ventilation in ICU patients with obesity. Non-invasive strategies should first optimize body position with reverse Trendelenburg position or sitting position. Noninvasive ventilation (NIV) is considered as the first-line therapy in patients with obesity having a postoperative acute respiratory failure. Positive pressure pre-oxygenation before the intubation procedure is the method of reference. The use of videolaryngoscopy has to be considered by adequately trained intensivists, especially in patients with several risk factors. Regarding mechanical ventilation in patients with and without acute respiratory distress syndrome (ARDS), low tidal volume (6 ml/kg of predicted body weight) and moderate to high positive end-expiratory pressure (PEEP), with careful recruitment maneuver in selected patients, are advised. Prone positioning is a therapeutic choice in severe ARDS patients with obesity. Prophylactic NIV should be considered after extubation to prevent re-intubation. If obesity increases mortality and risk of ICU admission in the overall population, the impact of obesity on ICU mortality is less clear and several confounding factors have to be taken into account regarding the "obesity ICU paradox".
Topics: Humans; Intensive Care Units; Obesity; Respiration, Artificial; Respiratory Distress Syndrome; Risk Factors; Tidal Volume
PubMed: 33095284
DOI: 10.1007/s00134-020-06286-x -
Critical Care (London, England) Jul 2021A personalized mechanical ventilation approach for patients with adult respiratory distress syndrome (ARDS) based on lung physiology and morphology, ARDS etiology, lung... (Review)
Review
A personalized mechanical ventilation approach for patients with adult respiratory distress syndrome (ARDS) based on lung physiology and morphology, ARDS etiology, lung imaging, and biological phenotypes may improve ventilation practice and outcome. However, additional research is warranted before personalized mechanical ventilation strategies can be applied at the bedside. Ventilatory parameters should be titrated based on close monitoring of targeted physiologic variables and individualized goals. Although low tidal volume (V) is a standard of care, further individualization of V may necessitate the evaluation of lung volume reserve (e.g., inspiratory capacity). Low driving pressures provide a target for clinicians to adjust V and possibly to optimize positive end-expiratory pressure (PEEP), while maintaining plateau pressures below safety thresholds. Esophageal pressure monitoring allows estimation of transpulmonary pressure, but its use requires technical skill and correct physiologic interpretation for clinical application at the bedside. Mechanical power considers ventilatory parameters as a whole in the optimization of ventilation setting, but further studies are necessary to assess its clinical relevance. The identification of recruitability in patients with ARDS is essential to titrate and individualize PEEP. To define gas-exchange targets for individual patients, clinicians should consider issues related to oxygen transport and dead space. In this review, we discuss the rationale for personalized approaches to mechanical ventilation for patients with ARDS, the role of lung imaging, phenotype identification, physiologically based individualized approaches to ventilation, and a future research agenda.
Topics: Humans; Precision Medicine; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Mechanics
PubMed: 34271958
DOI: 10.1186/s13054-021-03686-3 -
Emergency Medicine Clinics of North... Aug 2022Acute respiratory distress syndrome (ARDS) occurs in up to 10% of patients with respiratory failure admitted through the emergency department. Use of noninvasive... (Review)
Review
Acute respiratory distress syndrome (ARDS) occurs in up to 10% of patients with respiratory failure admitted through the emergency department. Use of noninvasive respiratory support has proliferated in recent years; clinicians must understand the relative merits and risks of these technologies and know how to recognize signs of failure. The cornerstone of ARDS care of the mechanically ventilated patient is low-tidal volume ventilation based on ideal body weight. Adjunctive therapies, such as prone positioning and neuromuscular blockade, may have a role in the emergency department management of ARDS depending on patient and department characteristics.
Topics: Humans; Patient Positioning; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Insufficiency; Tidal Volume
PubMed: 35953211
DOI: 10.1016/j.emc.2022.05.002 -
Seminars in Respiratory and Critical... Jun 2022Mechanical ventilation is a life-support system used to ensure blood gas exchange and to assist the respiratory muscles in ventilating the lung during the acute phase of...
Mechanical ventilation is a life-support system used to ensure blood gas exchange and to assist the respiratory muscles in ventilating the lung during the acute phase of lung disease or following surgery. Positive-pressure mechanical ventilation differs considerably from normal physiologic breathing. This may lead to several negative physiological consequences, both on the lungs and on peripheral organs. First, hemodynamic changes can affect cardiovascular performance, cerebral perfusion pressure (CPP), and drainage of renal veins. Second, the negative effect of mechanical ventilation (compression stress) on the alveolar-capillary membrane and extracellular matrix may cause local and systemic inflammation, promoting lung and peripheral-organ injury. Third, intra-abdominal hypertension may further impair lung and peripheral-organ function during controlled and assisted ventilation. Mechanical ventilation should be optimized and personalized in each patient according to individual clinical needs. Multiple parameters must be adjusted appropriately to minimize ventilator-induced lung injury (VILI), including: inspiratory stress (the respiratory system inspiratory plateau pressure); dynamic strain (the ratio between tidal volume and the end-expiratory lung volume, or inspiratory capacity); static strain (the end-expiratory lung volume determined by positive end-expiratory pressure [PEEP]); driving pressure (the difference between the respiratory system inspiratory plateau pressure and PEEP); and mechanical power (the amount of mechanical energy imparted as a function of respiratory rate). More recently, patient self-inflicted lung injury (P-SILI) has been proposed as a potential mechanism promoting VILI. In the present chapter, we will discuss the physiological and pathophysiological consequences of mechanical ventilation and how to personalize mechanical ventilation parameters.
Topics: Humans; Lung; Positive-Pressure Respiration; Respiration, Artificial; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 35439832
DOI: 10.1055/s-0042-1744447 -
Intensive Care Medicine Dec 2020Mechanical ventilation may have adverse effects on both the lung and the diaphragm. Injury to the lung is mediated by excessive mechanical stress and strain, whereas the... (Review)
Review
Mechanical ventilation may have adverse effects on both the lung and the diaphragm. Injury to the lung is mediated by excessive mechanical stress and strain, whereas the diaphragm develops atrophy as a consequence of low respiratory effort and injury in case of excessive effort. The lung and diaphragm-protective mechanical ventilation approach aims to protect both organs simultaneously whenever possible. This review summarizes practical strategies for achieving lung and diaphragm-protective targets at the bedside, focusing on inspiratory and expiratory ventilator settings, monitoring of inspiratory effort or respiratory drive, management of dyssynchrony, and sedation considerations. A number of potential future adjunctive strategies including extracorporeal CO removal, partial neuromuscular blockade, and neuromuscular stimulation are also discussed. While clinical trials to confirm the benefit of these approaches are awaited, clinicians should become familiar with assessing and managing patients' respiratory effort, based on existing physiological principles. To protect the lung and the diaphragm, ventilation and sedation might be applied to avoid excessively weak or very strong respiratory efforts and patient-ventilator dysynchrony.
Topics: Diaphragm; Humans; Lung; Respiration; Respiration, Artificial; Ventilators, Mechanical
PubMed: 33140181
DOI: 10.1007/s00134-020-06288-9 -
Medizinische Klinik, Intensivmedizin... Nov 2021Weaning from invasive mechanical ventilation is challenging for the ICU team in terms of shortening time of ventilation via endotracheal tube in order to improve the...
Weaning from invasive mechanical ventilation is challenging for the ICU team in terms of shortening time of ventilation via endotracheal tube in order to improve the patient's prognosis by early extubation. Thereby prolonged mechanical ventilation (> 14 days), which is associated with risk of tracheotomy and prolonged weaning, shall be avoided. This article will give an overview about weaning categories, causes for weaning failure and strategies to overcome this problem. In the last part we will cover concepts in the process of prolonged weaning including discharge management with invasive mechanical ventilation.
Topics: Airway Extubation; Humans; Noninvasive Ventilation; Respiration, Artificial; Tracheostomy; Ventilator Weaning
PubMed: 34586430
DOI: 10.1007/s00063-021-00858-5 -
Respiratory Care Jun 2020The diaphragm is vulnerable to injury during mechanical ventilation, and diaphragm dysfunction is both a marker of severity of illness and a predictor of poor patient... (Review)
Review
The diaphragm is vulnerable to injury during mechanical ventilation, and diaphragm dysfunction is both a marker of severity of illness and a predictor of poor patient outcome in the ICU. A combination of factors can result in diaphragm weakness. Both insufficient and excessive diaphragmatic contractile effort can cause atrophy or injury, and recent evidence suggests that targeting an appropriate amount of diaphragm activity during mechanical ventilation has the potential to mitigate diaphragm dysfunction. Several monitoring tools can be used to assess diaphragm activity and function during mechanical ventilation, including pressure-derived parameters, electromyography, and ultrasound. This review details these techniques and presents the rationale for a diaphragm-protective ventilation strategy.
Topics: Diaphragm; Humans; Intensive Care Units; Lung; Muscle Contraction; Muscle Weakness; Muscular Atrophy; Respiration; Respiration, Artificial; Ultrasonography
PubMed: 32457172
DOI: 10.4187/respcare.07410