Introduction: Hypothermia is commonly observed in patients during and following surgery. Recent studies have demonstrated that hypothermic patients are more susceptible to postoperative wound infection. We hypothesized that hypothermia would cause an inhibition of leukocyte function. Therefore, we investigated the differences in perioperative leukocyte oxygen free radical release in normothermic (warm) and hypothermic (cold) patients. Methods: Following IRB approval, 51 patients scheduled for radical retropubic prostatectomy (RRP) under regional anesthesia and postoperative narcotic analgesia were enrolled. RRP patients were randomized to receive either forced air warming intra-operatively (warm; n=22) or routine care (cold; n=29). Blood was collected in liquid heparin (1 unit: 100uL) and EDTA from indwelling catheters, and kept in water baths set to the patient's tympanic temperature. Leukocyte oxygen free radical release was measured as peak luminescence in a lumi-aggregometer (Chrono-Log, Havertown, PA) set to the patient's temperature. Results were standardized against a known concentration of NaOCl and corrected for changes in leukocyte counts. Statistical analyses were performed by paired and unpaired Student t-tests. Results: (Figure Presented) *p<01 pre-op vs. post-op p<.05 between groups. Similar results were found at higher concentrations of fmlp (5×10-8 and 1×10-7 uM). Conclusion: Warm patients exhibit increased and cold patients exhibit decreased leukocyte oxygen free radical release following surgery. Hypothermia-induced inhibition of leukocyte reactivity may play a role in post-operative infection.
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine