Principles of artificial ventilation

Ventilators are commonly used in the operating theatre and in the intensive care unit to deliver artificial ventilation to the lungs. This article explores the physiological principles underpinning artificial ventilation, explains the classification of ventilators and the effects of ventilation on normal physiology. It examines the optimal ventilatory strategies for a range of medical conditions, whilst touching on newer advances in the ventilatory management of patients with respiratory failure. Patients with respiratory failure may be difficult to ventilate and the anaesthetist or intensivist must use their knowledge of normal respiratory physiology, the pathophysiology of acute respiratory distress syndrome (ARDS), asthma and chronic obstructive pulmonary disease (COPD), and the results of clinical trials to meet this challenge.