The impact of obstructive sleep apnoea on post-operative outcomes

Unrecognised obstructive sleep apnoea (OSA) has been associated with adverse cardiorespiratory perioperative outcomes. However, with changing anaesthetic and perioperative management, there is ongoing uncertainty about the importance of OSA as a risk factor for post-operative complications.

A cohort study involving subjects undergoing elective surgery was conducted. OSA was diagnosed with a limited channel sleep monitor. In subjects undergoing routine perioperative care, complications were identified based on the assessment of the attending clinical team. The primary outcome was a composite end-point of cardiorespiratory outcomes comprising myocardial infarction, atrial fibrillation, other arrhythmias, bradycardia, need for inotropic support, unplanned intensive care unit admission, pneumonia or respiratory failure.

Four hundred seventy-two subjects were recruited, with 356 being included in the analyses; 281 (79%) had OSA and 66 (19%) had severe OSA. Subjects with OSA did not have a significantly higher incidence of complications (5.7%) compared to those without (2.7%, adjusted relative risk 1.89 (0.23-15.67)). Additionally, complications were not increased in those with severe OSA.

Unrecognised OSA was not associated with an increase in clinically evident cardiorespiratory complications in this cohort. The lower complication rates compared with earlier studies suggest that increased use of less invasive surgical techniques, improved pain management and increased awareness of OSA have had an impact in reducing postoperative complications in this group. Further research is needed to clarify the impact of severe OSA on post-operative outcomes in different surgical cohorts with varying risk profiles in order to develop optimal perioperative pathways.