Sedation in PACU: indications, monitoring, complications

The aim of the present article is to review the indications, the monitoring and the complications of sedation in the post-anaesthesia care unit (PACU). In this setting, sedation is often an unwanted side effect of anaesthetic drugs that delay discharge, however it could be specifically indicated. Such indications include postoperative anxiety and agitation, airway management and mechanical ventilation, protection against myocardial ischaemia and intracranial hypertension control. Whenever sedation is used, an appropriate monitoring is useful to achieve an adequate level for the specific indication. Methods for sedation monitoring in PACU may be subjective (clinical scales) or objective (lower oesophageal sphincter contractility measurement, heart rate variability, evoked potentials and parameters derived from the electroencephalogram). The target score of the most common clinical scales has been reviewed according to the specific indication. An adequate monitoring is fundamental to avoid the complications of sedation including bradycardia, hypotension, prolonged mechanical ventilation and increased risk of respiratory tract infection as pointed out by many recent data. Therefore, sedation should be used carefully and with an adequate monitoring in post-operative patients not to affect negatively morbidity and mortality.