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Silva PL, Ball L, Rocco PRM, Pelosi P. Physiological and Pathophysiological Consequences of Mechanical Ventilation. Semin Respir Crit Care Med 2022; 43:321-334. [PMID: 35439832 DOI: 10.1055/s-0042-1744447] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
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.
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Affiliation(s)
- Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lorenzo Ball
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.,Department of Anesthesia and Critical Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neuroscience, Genoa, Italy
| | - Patricia R M Rocco
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.,Department of Anesthesia and Critical Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neuroscience, Genoa, Italy
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Leszek A, Wozniak H, Giudicelli-Bailly A, Suh N, Boroli F, Pugin J, Grosgurin O, Marti C, Le Terrier C, Quintard H. Early Measurement of ROX Index in Intermediary Care Unit Is Associated with Mortality in Intubated COVID-19 Patients: A Retrospective Study. J Clin Med 2022; 11:jcm11020365. [PMID: 35054058 PMCID: PMC8779507 DOI: 10.3390/jcm11020365] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/05/2022] [Accepted: 01/10/2022] [Indexed: 12/10/2022] Open
Abstract
COVID-19 patients often present with rapidly progressing acute hypoxemic respiratory failure, requiring orotracheal intubation with different prognostic issues. However, ICU specialists lack predictive tools to stratify these patients. We conducted a single-center cross-sectional retrospective study to evaluate if the ROX index, measured under non-invasive oxygenation support, can predict ICU mortality in a COVID-19 intubated patient cohort. This study took place in the division of intensive care at the Geneva University Hospitals (Geneva, Switzerland). We included all consecutive adult patients treated by non-invasive oxygenation support and requiring intubation for acute respiratory failure due to COVID-19 between 9 September 2020 and 30 March 2021, corresponding to the second local surge of COVID-19 cases. Baseline demographic data, comorbidities, median ROX between H0 and H8, and clinical outcomes were collected. Overall, 82 patients were intubated after failing a non-invasive oxygenation procedure. Women represented 25.6% of the whole cohort. Median age and median BMI were 70 (60–75) years and 28 (25–33), respectively. Before intubation, the median ROX between H0 and H8 was 6.3 (5.0–8.2). In a multivariate analysis, the median ROX H0–H8 was associated with ICU mortality as a protective factor with an odds ratio (95% CI) = 0.77 (0.60–0.99); p < 0.05. In intubated COVID-19 patients treated initially by non-invasive oxygenation support for acute respiratory failure, the median ROX H0–H8 could be an interesting predictive factor associated with ICU mortality.
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Affiliation(s)
- Alexandre Leszek
- Department of Medicine, Division of General Internal Medicine, Geneva University Hospitals, 1205 Geneva, Switzerland; (A.L.); (O.G.); (C.M.)
| | - Hannah Wozniak
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Amélie Giudicelli-Bailly
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Noémie Suh
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Filippo Boroli
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Jérôme Pugin
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Olivier Grosgurin
- Department of Medicine, Division of General Internal Medicine, Geneva University Hospitals, 1205 Geneva, Switzerland; (A.L.); (O.G.); (C.M.)
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Christophe Marti
- Department of Medicine, Division of General Internal Medicine, Geneva University Hospitals, 1205 Geneva, Switzerland; (A.L.); (O.G.); (C.M.)
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Christophe Le Terrier
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
| | - Hervé Quintard
- Department of Acute Medicine, Intensive Care Unit, Geneva University Hospitals, 1205 Geneva, Switzerland; (H.W.); (A.G.-B.); (N.S.); (F.B.); (J.P.); (C.L.T.)
- Correspondence:
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