Postoperative Adverse Events in Morbidly Obese Patients Undergoing Anesthesia: A Retrospective Study

Objective: To determine the incidence of postoperative respiratory complications among morbidly obese patients who had undergone anesthesia. Material and Method: This retrospective chart review was conducted at two centers, Siriraj Hospital and Buddhachinaraj Hospital. Adult in-patients aged greater than or equal to 18, with a body mass index (BMI) greater than or equal to 35 kg/m², and who had undergone non-cardiac surgery and anesthesia, were enrolled. The postoperative respiratory adverse events, such as pneumonia, pulmonary embolism, re-intubation, airway obstruction and airway trauma, were recorded. Results: A total of 830 medical records of morbidly obese patients who had been admitted at the two medical centers between October 2013 and December 2016 were retrieved. Around two-thirds of patients were female. The patients’ mean age was 46.4 years old (the maximum was 98, and the minimum 18), with a mean BMI of 38.83 kg/m² (the maximum was 78.5 kg/m², and the minimum 35 kg/m²). The overall perioperative respiratory adverse events numbered 37 (4.5%). The postoperative respiratory adverse event was re-intubation (0.5%); the remaining postoperative respiratory adverse events were pneumonia (0.1%) and upper airway obstruction (0.1%). All those cases had undergone general anesthesia, and their American Society of Anesthesiologists (ASA) Physical Status classification was greater than, or equal to, class 3. Conclusion: The incidence of postoperative respiratory adverse events was minimal; therefore, risk factors were unable to be identified.