Intraoperative hypothermia during cytoreductive surgery for ovarian cancer and perioperative morbidity

OBJECTIVE: To evaluate intraoperative hypothermia as a predictor for morbidity after open abdominal surgery for ovarian cancer. METHODS: This cohort study included 146 women with stage IIIC and IV ovarian cancer who underwent debulking surgery at our institution from January 1, 2001, through December 31, 2003. Hypothermia was defined as end operative temperature lower than 36° C. Early complications (occurring within 30 days of surgery) included: mortality, infectious morbidities, cardiovascular events, venous thromboembolic (VTE) events, anastomotic leak, readmission, and reoperation. Survival was also evaluated. Logistic regression models were used to adjust for known confounders. RESULTS: The mean age was 63.9±11.7 years; 46 (32%) patients had a body mass index higher than 30; mean operative time was 239±85 minutes. There were five deaths perioperatively, all in the hypothermic group. Hypothermia was associated with an increased risk of any early complications (34 [42.0%] compared with 11 [16.9%]) with an adjusted odds ratio (OR) of 3.40 (95% confidence interval [CI] 1.48-8.33). For individual complications, hypothermic patients were at higher risk for VTE events with an adjusted OR of 3.53 (95% CI 1.02-16.44); infectious morbidity with an adjusted OR of 2.99 (95% CI 0.97-11.35); and reoperation with an adjusted OR of 4.96 (95% CI 0.80 -95.7). The overall survival was shorter in hypothermic group with a median of 34 compared with 45 months (P=.045); this remained significant for an optimally resected subgroup with a median overall survival of 40 compared with 48 months (P=.049). CONCLUSION: Surgical hypothermia is an independent predictor of early perioperative complications and overall survival after cytoreductive surgery for ovarian cancer. This is a critically important finding, because maintaining normothermia is an inexpensive modifiable factor, which could result in reduced morbidity.