PURPOSE: Literature addressing the acute effects of sleep apnea in patients undergoing coronary artery bypass grafting (CABG) and other cardiac surgeries, which are commonly performed in patients with CAD, is sparse. The objective of this retrospective study is to compare the incidence of perioperative complications in patients with and without OSA who undergo cardiac surgery.
METHODS: Inclusion criteria: The Cleveland Clinic Cardiac Surgery and Sleep Center databases were used to identify the patients who underwent an open heart surgery within two years of the date of the polysomnogram (PSG) between January 1995 and December 2000. An assumption was made that if the surgery was performed within two years of the diagnosis of OSA, the patient had OSA at the time of the surgery. During this period 25,587 patients were identified in the cardiac surgery database of which 37 were diagnosed with OSA by PSG.To balance the differences and reduce bias propensity analysis was used to select a sample from patients without OSA.
RESULTS: Higher incidence of encephalopathy (p=0.008), postoperative infection (0.028) and increased ICU length of stay (p=0.031) were noted in the group with OSA after cardiac surgery. The difference in the rates of infection was mostly accounted for by the presence of mediastinitis (8.1% vs 1.08%). This could be attributed to prolonged ventilator support and higher length of ICU stay. However,differences in the rates of reintubation, tube time, and overall postoperative morbidity were not statistically significant.
CONCLUSION: Increased risk for postoperative complications is suggested in patients with OSA undergoing cardiac surgery. This risk is underestimated on account of lack of awareness about the incidence of OSA in the general population and the cardiovascular population in particular, difficulties in clinical suspicion and diagnosis and limited use of polysomnography.
CLINICAL IMPLICATIONS: OSA may need to be identified and diagnosed prior to cardiovascular surgery. Patients with OSA are more often diabetic but have an independently higher tendency to develop infections viz., mediastinitis.They also had higher rates of encephalopathy and longer ICU stay postoperatively.
DISCLOSURE: Roop Kaw, None.