OSA and Perioperative Complications in Bariatric Patients

Article in the British Journal of Anaesthesia about OSA and complications around the time of surgery in obese patients. Obese patients, with and without OSA, are at higher surgical risk. It's assumed that OSA is an independent risk factor for perioperative complications, but the article says there is not much objective data to support that.

Currently, bariatric surgeons typically have their patients have a sleep study prior to weight loss surgery. If there is significant OSA, than the patient is treated for several weeks to months with CPAP prior and upto the weight loss surgery.

The authors of this study studied patients that had a pre-op sleep study. Ninety-three percent of the patients with OSA received perioperative positive airway pressure therapy. All patients were closely monitored after operation. The overall complication rate was increased with open procedures compared with laparoscopic. In addition, increased BMI and age were associated with increased likelihood of pulmonary and other complications. Complication rates were not associated with OSA severity.

The authors concluded that in obese patients evaluated by sleep study before bariatric surgery and managed accordingly, the severity of OSA (the AHI), was not associated with the rate of perioperative complications. Thus, either OSA is not an independent risk factor for complications or the recognition and management of OSA in the perioperative period mitigates this risk. These results cannot determine whether unrecognized and untreated OSA increases risk.

Sleep Apnea Increases Pulmonary Complications After Surgery

There is an article in the January issue of Anesthesia & Analgesia that warns that patients with sleep apnea have more frequent pulmonary complications after orthopedic and general surgery. I am not sure if this included sleep apnea patients that were treated. The risk of being intubated and put on a mechanical ventilator went up five-fold after orthopedic surgery and two-fold after general surgery. Other complications that were increased after these surgeries included aspiration pneumonia (lung infection after stomach contents are inhaled) and pulmonary embolus (lung clots).

This study points to the importance of pre-surgical screening for sleep apnea, so that anesthesiologists and surgeons are aware of the risk. Also, it would be interesting to know if treating sleep apnea reduces these pulmonary risks.