The obesity paradox in surgical intensive care patients with peritonitis

Although obesity is usually regarded as a risk factor in surgical patients, various observations have revealed a better outcome in the obese. This finding is called the obesity paradox. To which group of patients the paradox applies and even whether it exists at all are matters of controversial discussion.

We retrospectively analyzed 253 consecutive patients with surgical peritonitis and sepsis who needed intensive care for more than 2 days postoperative. Patients were assigned to groups according to body mass index (BMI), and groups were compared with respect to outcome parameters.

In the 4 BMI groups--less than 21, 21 to 25, 26 to 30, and more than 30 kg/m(2)--mortality rate at 28 days was 73%, 50%, 42%, and 31%, respectively. The relative risk of death at 28 days in the BMI greater than 30 kg/m(2) group compared to the normal weight group (BMI, 21-25.9 kg/m(2)) was 0.66 (95% confidence interval, 0.28-0.94). However, mortality rate at 5 years was 90%, 70%, 69%, and 75%, respectively. Patients in the lowest BMI range were less likely to be discharged home. Intensive care unit and hospital length of stay was longest in the group of highest BMI, and that group had the best mean survival (386 days for BMI >30 kg/m(2) vs 113 days for BMI <21 kg/m(2)).

The "obesity paradox" may exist in patients with surgical peritonitis. Short-term but not long-term outcomes were improved in the obese. Concerns about obesity as a special risk factor in patients with peritonitis are not warranted according to our findings.