Preoperative oximetry-derived hypoxemia predicts postoperative cardiovascular events in surgical patients with unrecognized obstructive sleep apnea
Institution:
1. Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada;2. University of Malaya, Kuala Lumpur, Malaysia;3. Khoo Teck Puat Hospital, National Healthcare Group, Singapore;4. The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China;1. UPMC Children''s Hospital of Pittsburgh, Department of Anesthesiology and Perioperative Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA;2. Division of Pediatric Interventional Radiology, UPMC Children''s Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, USA;1. Department of Anaesthesia, The Queen Elizabeth Hospital, Woodville, South Australia, Australia;2. Discipline of Acute Care Medicine, The University of Adelaide, South Australia, Australia;3. Department of Anesthesia, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
Abstract:
Study objectiveObstructive sleep apnea (OSA) is known to be associated with postoperative cardiovascular events in patients undergoing major non-cardiac surgery. The objective of the study is to determine whether preoperative oximetry-derived hypoxemia predicts postoperative cardiovascular events in surgical patients with unrecognized obstructive sleep apnea.Design and settingThe study was a planned post hoc analyses of a multicenter prospective cohort study.PatientsThe inclusion criteria were patients ≥45 years old undergoing major non-cardiac surgery with cardiovascular risk factors.Interventions and measurementsAll patients underwent pre-operative pulse oximetry (PULSOX-300i, Konica-Minolta Sensing, Inc). The severity of OSA was classified based on oxygen desaturation index (ODI) (mild: ≥5 to <15, moderate: ≥15 to <30, and severe OSA: ≥30 events/h). The 30 days cardiovascular events were a composite of myocardial injury, cardiac death, congestive heart failure, thromboembolism, atrial fibrillation, and stroke.Main resultsFor 1218 patients with mild, moderate, or severe OSA (mean age: 67.2 ± 9.3 years; body mass index: 27.0 ± 5.3 kg/m2), the rate of postoperative cardiovascular events was 16.4%, 25.2%, and 29.8% respectively. The multivariable analysis showed that preoperative oxygen desaturation index (ODI) ≥30 events per hour {adjusted hazard ratio (aHR) 1.63 95% confidence interval (CI): 1.05–2.53]}, and cumulative time spent during sleep with oxygen saturation below 80% (CT80) ≥10 min {aHR 1.79 95% CI: 1.28–2.50]} were independent predictors of 30-day postoperative cardiovascular events.ConclusionsPreoperative ODI ≥30 events per hour and CT80 ≥ 10 min are associated with increased risk of postoperative cardiovascular events. Preoperative screening using oximetry helps in risk stratification for unrecognized sleep apnea.Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT01494181
