[Is obesity a risk factor for complications, hospital admissions, and surgical cancellations in ambulatory surgery?]

To determine the incidence of outcomes, unanticipated admissions and cancellations in patients operated in an Ambulatory surgery unit, and to establish the relationships with their body mass index (BMI).

An observational descriptive prospective study was conducted in the Ambulatory surgery unit of the University Hospital Virgen del Rocío of Seville, on ASA I or II adult patients proposed for day case surgery with loco-regional or general anesthesia. A cohort of 1,088 patients was classified according to their body mass index into four groups: no obesity (BMI<30), obesity i (BMI 30-34.9), obesity ii (BMI 35-39.9), and morbid obesity iii (BMI 40-49.9). Postoperative outcomes (48h), inpatient admissions, and cancellations where calculated.

The obesity ii (BMI 35-39.9) group showed a higher incidence of postoperative complications (7.69%), unplanned admissions (7.69%), and surgical cancellations (4.87%), doubling, at least, the incidence of adverse events of the other study groups, even when no significant difference was found. Outcomes where similar in all study groups.

The results of this study suggest that moderate and severe obesity should be a risk factor for postoperative complications, unplanned admissions, and cancellations in outpatient surgery. Adequate patient selection and preoperative evaluation, as well as strategies for the prevention and control of the most frequents complications in obese patients are the key factors for their integration in major ambulatory surgery programs.