PREOPERATIVE NEUTROPHIL AND MONOCYTE ACTIVATION STATE PREDICTS POSTOPERATIVE NEUTROPHIL AND MONOCYTE FUNCTION

Objective: To find out if the in vitro responses of neutrophils (PMN) and monocytes preoperatively can predict their activation postoperativ ely. Design: Prospective open study. Setting: Teaching hospital, Irela nd. Subjects: 46 Patients (32 men, 14 women, mean age 65 years, range 33-85) who were to undergo elective major vascular or gastrointestinal operations for benign (n=18) or malignant (n=28) diseases. Interventi ons: Measurement by flow cytometry of functional (PMN and monocyte res piratory burst activity) and phenotypic (expression of PMN CD 11b adhe sion receptors and monocyte CD14 receptors) markers of activation. Mai n outcome measures: Correlation between mean channel fluorescence (MCF ) preoperatively and postoperatively. Results: In 24 patients PMN resp iratory burst activity was increased before operation and had decrease d significantly (p<0.01) on postoperative day 1 (high responders group ). In the remaining 22 patients (low responders group) respiratory bur st activity was low before operation and had increased significantly ( p<0.05) on postoperative day 1. PMN CD 11b activity followed a similar trend. Monocyte activity responded similarly (in the high group mean (SEM) MCF preoperatively was 69.14 (13.15) compared with 58.23 (10.8) on day 1, and in the low group the corresponding figures were 38.5 (7. 01) and 8.43 (5.2). Expression of CD14 did not differ between the grou ps and was less postoperatively than preoperatively. The groups did no t differ in age, sex, APACHE 11 scores, smoking habits or types of dis ease and there was no major infective complications in either group. C onclusion: There are two distinct patterns of PMN and monocyte respons es to injury that are independant of age, sex and severity of operatio n. These may be associated with the degree of stress preoperatively or with genetic factors.