Decreased endotoxin immunity is associated with greater mortality and/or prolonged hospitalization after surgery

Background: Patients undergoing noncardiac surgery often develop postoperat ive morbidity, potentially attributable to endotoxemia and the systemic inf lammatory response syndrome. Endogenous antibodies to endotoxin may confer protection from endotoxin-mediated toxicity. The authors sought to determin e the association of preoperative antiendotoxin immunity and death or prolo nged hospitalization in a broad population of general surgical patients und ergoing major surgery. Methods: To test the hypothesis that low preoperative serum antiendotoxin c ore antibody (EndoCAb) concentration is an independent predictor of adverse outcome after general surgery, 1,056 patients undergoing routine noncardia c surgery were enrolled into a prospective, blinded, cohort study. Immunogl obulin M EndoCAb, immunoglobulin G EndoCAb, total immunoglobulin M, and imm unoglobulin G concentrations were measured in serum obtained preoperatively . A physiologic risk score using the established POSSUM criteria was assign ed preoperatively to each patient. The primary predefined composite end poi nt (postoperative complication) was either in-hospital death or postoperati ve length of stay greater than 10 days. Multivariate logistic regression wa s used to test the study hypothesis. Results: Overall, postoperative complication occurred in 234 of the 1,056 p atients (22.1%). lower immunoglobulin hi EndoCAb concentration (P = 0.006) predicted increased risk of postoperative complication independent of POSSU M physiologic risk score(P < 0.001). In contrast, total immunoglobulin M an d total immunoglobulin G concentrations did not predict adverse outcome, Co mplications involved multiple organ systems and were generally unrelated to the type or site of surgery, consistent with the systemic inflammatory res ponse syndrome. Conclusions: Adverse outcome after routine noncardiac surgery is common and is predicted in part by low concentrations of EndoCAb. The authors' findin gs suggest that endotoxemia may be a cause of postoperative morbidity after routine noncardiac surgery.