ICU · Respiratory
Mechanical Ventilation
Also known as Positive-pressure ventilation · Invasive ventilation · Intermittent positive-pressure ventilation (IPPV) · Ventilator modes · Lung-protective ventilation
Mechanical ventilation applies positive pressure to the airway to support gas exchange and unload the respiratory muscles. Its overriding principle is lung-protective ventilation — tidal volume around 6 mL/kg predicted body weight, plateau pressure at or below 30 cmH2O, the lowest achievable driving pressure (15 cmH2O or more flags excess mortality), and PEEP titrated against FiO2 on a predetermined combination table to the least injurious pairing that oxygenates — because the ventilator that saves the patient can also destroy the lung it ventilates through volutrauma, atelectrauma and biotrauma.
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Red flags
- A rising peak airway pressure with a normal or low plateau pressure localises the problem to the circuit or airway (obstruction, kink, secretions, bronchospasm, biting)
- A driving pressure (plateau minus PEEP) of 15 cmH2O or more is the ventilatory variable most strongly associated with mortality
- Unrecognised intrinsic (auto-)PEEP in COPD or asthma causes hypotension, weaning failure and ineffective triggering
- Right ventricular failure can be precipitated by high PEEP and high driving pressure, which raise pulmonary vascular resistance
- Hypotension at the onset of ventilation suggests reduced venous return in the volume-depleted patient — give volume and reduce PEEP
Meet the patient
A 64-year-old man with community-acquired pneumonia is intubated for hypoxaemia that escalation on non-invasive ventilation could not correct. He is now on volume control, tidal volume 500 mL, rate 16, PEEP 10 cmH2O, FiO2 0.9. His plateau on an inspiratory hold is 34 cmH2O. The team asks: is this lung-protective, and is it time to prone? The answer lives in three numbers you can measure at the bedside — tidal volume on predicted weight, plateau, and driving pressure.[1][2]
The two questions that decide every ventilated patient are: is the lung being protected? (the three numbers above answer that) and is the patient ready to come off? (the spontaneous-breathing trial answers that). Hold those questions and every dial, alarm, and waveform falls into place.[1]
References21ShowHide
- [1]Brower RG, Matthay MA, Morris A, et al. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome N Engl J Med, 2000.PMID 10793162
- [2]Amato MBP, et al. Driving pressure and survival in the acute respiratory distress syndrome N Engl J Med, 2015.PMID 25693014
- [3]Dreyfuss D, et al. High inflation pressure pulmonary edema. Respective effects of high airway pressure, high tidal volume, and positive end-expiratory pressure Am Rev Respir Dis, 1988.PMID 3057957
- [4]Fan E, et al. An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome Am J Respir Crit Care Med, 2017.PMID 28459336
- [5]Gallagher JJ, Adamski JL. Mechanical Ventilation: Modes, Settings, and Clinical Considerations AACN Adv Crit Care, 2025.PMID 41364850
- [6]Merola R, et al. Ventilator-Induced Lung Injury: The Unseen Challenge in Acute Respiratory Distress Syndrome Management J Clin Med, 2025.PMID 40507672
- [7]Joseph A, et al. Hemodynamic effects of positive end-expiratory pressure Curr Opin Crit Care, 2024.PMID 38085886
- [8]Holanda MA, et al. Patient-ventilator asynchrony J Bras Pneumol, 2018.PMID 30020347
- [9]Bulleri E, et al. Patient-ventilator asynchronies: types, outcomes and nursing detection skills Acta Biomed, 2018.PMID 30539927
- [10]Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation N Engl J Med, 1991.PMID 2023603
- [11]Brochard L, et al. Comparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation Am J Respir Crit Care Med, 1994.PMID 7921460
- [12]Esteban A, et al. A comparison of four methods of weaning patients from mechanical ventilation. Spanish Lung Failure Collaborative Group N Engl J Med, 1995.PMID 7823995
- [13]Guérin C, et al. Prone positioning in severe acute respiratory distress syndrome N Engl J Med, 2013.PMID 23688302
- [14]Gattinoni L, et al. The baby lung became an adult Intensive Care Med, 2016.PMID 26781952
- [15]Evans L, et al. Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021 Intensive Care Med, 2021.PMID 34599691
- [16]Brower RG, et al. Higher versus lower positive end-expiratory pressures in patients with the acute respiratory distress syndrome N Engl J Med, 2004.PMID 15269312
- [17]Lay YY, et al. Ventilator-derived Versus Standard Rapid Shallow Breathing Index for Weaning Assessment: A Systematic Review In Vivo, 2026.PMID 42379753
- [18]Richard JC, et al. Feasibility and safety of ultra-low tidal volume ventilation without extracorporeal circulation in moderately severe and severe ARDS patients Intensive Care Med, 2019.PMID 31549225
- [19]Jubran A, et al. Setting positive end-expiratory pressure in the severely obstructive patient Curr Opin Crit Care, 2024.PMID 38085854
- [20]Pensier J, et al. Effects of inflammatory phenotypes in acute respiratory distress syndrome on mortality and partitioning of lung and chest wall mechanics in patients in the USA and Canada: a retrospective cohort study Lancet Respir Med, 2026.PMID 42155495
- [21]Kowsthubha BG, et al. Pediatric versus adult self-inflating bags for cardiopulmonary resuscitation of adult patients with cardiac arrest Resuscitation Plus, 2026.PMID 42290701