To study the nature and frequency of postoperative complications after Noncardiac surgery(NCS)among patients with Obstructive Sleep Apnea(OSA).
The Internal Medicine preoperative assessment,consultation and treatment (IMPACT)and Polysomnography (PSG) databases were crossmatched to identify patients who underwent both NCS and PSG at a major tertiary care center. OSA (apnea-hypopnea index-AHI>5) was presumed to be present at the time of surgery, even if established by PSG within 3 years after NCS. Among patients who underwent multiple procedures, those with higher surgical risk class and the most recent PSG prior to the chosen NCS were selected. Impact of OSA on postoperative outcomes was analyzed with a multivariate logistic model that was adjusted for age, gender, race, type of anesthesia, BMI, ASA class and medical comorbidities.
A total of 471 patients underwent both NCS and PSG between Feb 2002 and June 2006. A total of 262(56%)patients had OSA and majority of NCS(80%)were intermediate risk. Continous positive airway pressure(CPAP) was recommended to 152(58%)patients after diagnosis but was not consistently resumed postoperatively. Presence of OSA was associated with higher risk of unplanned ICU transfer (OR=4.1, p=0.047), higher overall complications (OR=6.4, p=0.0005) and longer hospital stay (OR= 1.7, p=0.04). Postoperative respiratory failure was the most frequent complication among OSA cases(6% vs 2%) but the difference was not statistically significant(p=0.18). Severity of OSA defined by higher AHI was not associated with postoperative complications (p=0.21) or hospital length of stay(LOS)(p=0.35). 70% of OSA patients recommended home CPAP were compliant as reported at their preoperative assessment. Among OSA patients, use of CPAP at home prior to NCS did not lower the risk of postoperative complications (p=0.80) or hospital(LOS)(p=0.19).
Higher risk of postoperative complications is noted after NCS in patients with OSA, resulting in unplanned ICU admissions and longer hospital stay. Further studies are needed to understand the impact of severity of OSA and perioperative CPAP use on postoperative outcomes.
Patients with OSA should be closely monitored postoperatively. Resuming CPAP immediately postoperatively may help reduce this risk.
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