Applied respiratory physiology

Applied respiratory physiology is crucial for perioperative patient management. This article reviews respiratory mechanics, gas exchange, and ventilation regulation, focusing on their practical applications from preoperative assessment to postoperative recovery. Cardiopulmonary exercise testing (CPET) is emphasized for predicting perioperative risk, with metabolic equivalents (METs) highlighted as indicators of cardiovascular fitness. The significance of oxygen delivery (DO2) components and types of hypoxia are detailed. Anaesthesia's effects on respiratory physiology, including the suppression of ventilatory response and impact on upper airway muscles, are analysed. Postoperative strategies to prevent atelectasis, such as positive endexpiratory pressure (PEEP) and recruitment manoeuvres, are discussed.