Weighing in: Effect of BMI on Postoperative Fever and Complications in Patients Undergoing Three Distinct Surgeries

BACKGROUND: Current trends estimate a 33% increase in obesity and 130% increase in severe obesity by the year 2030. It is unclear what the effect of obesity is on postoperative fevers, postoperative complications, and diagnostic workup rates. METHODS: We evaluated 5,330 patients undergoing knee arthroplasty, colectomy, or craniectomy from October 2009 to December 2014 at NorthShore University HealthSystem, in Illinois. Clinical data were extracted from the Enterprise Data Warehouse, including diagnostic testing and complications. Complications were also verified by physician chart review. Χ(2) and Mann–Whitney U tests were used to analyze categorical and continuous variables. RESULTS: Obesity (BMI ≥ 35) was present in 1081 (23.4%) of knee arthroplasty, 38 (16.9%) of colectomy and 55 (12.6%) of craniectomy patients. There was no increase in complications by BMI in each individual surgery except for increased 30-day readmissions in craniectomy patients with BMI ≥ 35 (P = 0.032). Collectively, there was no difference in the relationship between BMI and rate of post-op complications (Table 1). However, patients with BMI ≥ 35 experienced more fevers (P = 0.002), underwent additional workup (0.011), and had higher workup costs (P < 0.001). CONCLUSION: Patients with BMI ≥ 35 had more fevers, more workups and higher cost, but not higher complication rates during the index hospitalization after surgery. Awareness of the predisposition towards post-op fever in obese patients in the absence of complication may prevent costly and unnecessary testing. More work is still needed to understand the effect of obesity on more distant complication rates. DISCLOSURES: All authors: No reported disclosures.