Impact on clinical outcomes, surgical interventions, anaesthetic decisions and complication rates following implementation of the NICE OSA guidelines during preoperative screening.

Introduction: Unidentified OSA can lead to unexpected perioperative complications, unplanned postoperative admissions and increased length of hospital stay. The NICE (National Institute of Clinical Excellence) recommends a rapid preoperative assessment for patients undergoing elective surgery.

Methods: We have evaluated the impact on implementing the NICE guidelines on clinical outcomes, surgical interventions, anaesthetic decisions and complication rates in surgical patients referred from the pre assessment clinic prior to an elective intervention. All patients with a clinical suspicion of OSA based on a STOP-BANG score of 3 or more were referred for an overnight oximetry. Demographics, clinical outcomes and the impact on the planned surgical procedures were evaluated.

Results: 450 patients (Age- 55 ± 14, Males- 69%, ESS- 7 ± 5) with a STOP BANG score of 3 or more underwent an overnight oximetry (32%; normal, 44%; mild, 15%; moderate and 9%; severe OSA). All moderate and severe OSA were recommended for CPAP therapy to facilitate their surgical procedures and for long term cardio-metabolic benefits. Diagnosis of moderate/severe OSA had an impact on the surgical decision (P < 0.0001, OR= 3.79, 95% CI= 2.39-6.02). Severity of OSA affected the planned anaesthetic route (P < 0.0001, OR= 3.94, 95% CI= 2.21- 7.05). No significant difference in day case v/s non-day case, need for unplanned admissions to critical care due to better planning pre procedure. CPAP was initiated preoperatively in a third of patients (mean compliance- 3.75 hours/day) and the overall complication rate was 11.6% in the moderate/severe OSA group v/s 9.6% in the normal/mild group.

Conclusion: Prevalence of OSA is high in pre surgical patients identified through preoperative screening. A diagnosis of moderate to severe OSA impacts surgical decision and planned anaesthetic route. Prior awareness of the diagnosis may help clinicians to identify the at-risk group. Timely CPAP initiation to facilitate surgery remains a challenge and despite low compliance, CPAP may reduce postoperative complications. An MDT approach and a dedicated CPAP pathway post diagnosis may help the clinicians and patients.