Risk stratification for obstructive sleep apnoea and optimal post-operative monitoring in an overnight stay ward

Abstract

Objectives: Prospective data is required to clarify the role of a one night stay ward (23-hour ward, 23HW) for the post-operative monitoring of surgical patients with obstructive sleep apnoea (OSA). The aim was to use a modified American Society of Anesthesiologists (ASA) screening tool to stratify the perioperative risk of OSA related complications and evaluate the role of a 23HW in the post-operative management of this patient group.

Design: Prospective cohort study.

Setting: Tertiary referral centre.

Subjects: Patients identified in pre-anaesthetic clinic as having a mild to moderate risk of complications from OSA were scheduled for post-operative monitoring in a 23HW.

Outcome measures: Primary end points were incidence of desaturation events (Continuous pulse oximetry measuring SpO2 90-94% mild, <90% severe) in the recovery unit and in the 23HW. Secondary endpoints included type of anaesthetic, utilisation of continuous positive airway pressure (CPAP) and oxygen therapy, and major adverse events.

Results: One hundred seventy three patients (median age 56) were identified. Of these, 61 had previous formal diagnosis of OSA by sleep study while the remaining 112 patients were provisionally diagnosed in pre-anaesthetic clinic by clinical parameters. Ninety-four patients received a general anaesthetic, 79 patients received regional anaesthesia with sedation. The incidence of desaturation events was 4.0% in the Recovery Unit and 22.0% in the 23HW.

Conclusion: The ASA screening tool can identify perioperative patients at risk of developing respiratory complications from OSA, enabling their safe monitoring in a 23HW, thus avoiding the need for limited High Dependency Unit resources.