Obstructive sleep apnoea and anaesthesia

Upper airway obstruction is common during both anaesthesia and steep, as a result of loss of muscle tone present during wakefulness. Patients with obstructive steep apnoea (OSA) are vulnerable during anaesthesia and sedation as the effects of loss of wakefulness are compounded by drug-induced depression of muscle activity and of arousal responses, so that they cannot respond to asphyxia. Conversely, those with 'difficult' airways during anaesthesia, either because of problems with maintenance of airway patency without tracheal. intubation or because intubation itself is problematic, are at increased risk of OSA. These relationships have clinical importance. On the one hand identification of patients with OSA forewarns the anaesthetist of potential difficulty with airway maintenance intra- and postoperatively, influencing choice of anaesthetic technique and postoperative nursing environment. On the other hand difficulty with airway maintenance during anaesthesia should prompt further investigation for the possibility of OSA. (C) 2004 Elsevier Ltd. All rights reserved.