Do sleep studies effectively predict postoperative ventilatory requirements in patients undergoing bariatric surgery?

Introduction

Preoperative identification of obstructive sleep apnea (OSA) may help in the selection of patients who require ventilatory support. This study investigates the value of sleep studies in predicting the requirement for postoperative continuous positive airway pressure ventilation (CPAP) and high-dependency unit (HDU) admission.

Methods

During the development of our service since 2001, 34 consecutive patients, mean age 42 years (29–61), mean weight 146 kg (100–210), mean BMI 54 (39–75), all underwent preoperative assessment by a respiratory physician before laparoscopic adjustable gastric banding, based on which 28 had sleep studies while six did not. The decision to provide CPAP was determined by sleep study results: patients with moderate or severe OSA were electively prescribed CPAP preoperatively and postoperatively.

Results

Sleep studies were normal in 19 patients (NSS) and abnormal in nine patients (ABSS). In ABSS, OSA was severe in four patients, moderate in one patient, and mild in four patients. Preoperative and postoperative CPAP was prescribed electively for the five patients with moderate and severe OSA. Postoperatively, 3/19 of the NSS patients required CPAP and were admitted to the HDU. Another NSS patient was admitted to the HDU because of her age (61 years). The duration of operation, stay in recovery, and timing of extubation were comparable for NSS and ASS. The mean BMI was 63 and 53 in ASS and NSS patients, respectively (P = 0.05).

Conclusion

Postoperative CPAP and HDU admission was required in 21% of NSS patients. Although ABSS was associated with higher BMI, sleep studies do not reliably predict postoperative CPAP or HDU requirements.