Fever evaluations after colorectal surgery: identification of risk factors that increase yield and decrease cost.

Abstract

This study was designed to evaluate the yield and cost of fever evaluations in average-risk inpatients after elective colorectal surgery. A 12-month, retrospective study was performed on patients who developed a postoperative fever > or = 38 degrees C after elective colorectal surgery. A positive fever evaluation was defined as a blood culture, urine culture, chest x-ray, or abdominal CT result that led to a change in patient management. Logistic regression, Fisher's exact test, and chi-squared test were used; odds ratios were calculated. Of 133 patients, 26 percent had a positive evaluation. Blood culture, urine culture, chest x-ray, and CT were positive in 3, 8, 7, and 46 percent, respectively. Risk factors for a positive fever evaluation were temperature > or = 38.5 degrees C, fever evaluation after postoperative Day 6, and a clinical manifestation of systemic inflammatory response syndrome other than fever (all, P < 0.01). The cost per positive fever evaluation for the entire group, patients with 2 risk factors, or patients with 3 risk factors was $5,600, $4,200, and $2,140, respectively. The current approach to fever evaluation after elective colorectal surgery is low yield and costly. High fever, late postoperative fever, and systemic inflammatory response syndrome are risk factors for a positive fever evaluation after colorectal surgery.