Is Preoperative Antiendotoxin Immunity Associated with Postsurgical Outcome? Bennett-Guerrero et al. (page 992)

Bennett-Guerrero et al.  enrolled 1,056 patients scheduled to undergo routine noncardiac surgery (general, orthopedic, urological, vascular, and gynecologic procedures) in a prospective, observational study to determine whether preoperative antiendotoxin immunity might confer protection against perioperative inflammatory response. Using serum samples obtained 72 h before surgery, the team conducted assays for patients’ concentrations of immunoglobulin (Ig) M antiendotoxin core antibody (EndoCAb), IgG, EndoCAb, total IgM, and to-tal IgG. In addition, patients were assessed using the POSSUM physiologic scoring system, including 12 preoperative factors: age, signs of symptoms of heart failure, abnormal electrocardiogram, respiratory function, blood pressure, heart rate, mental status, hemoglobin level, leukocyte count, blood urea concentration, blood sodium concentration, and blood potassium concentration.

For purposes of this study, the authors defined adverse postoperative outcome either as in-hospital death or as hospital stay greater than 10 days. (Patients enrolled in the study included only those scheduled to undergo procedures that targeted their discharge from the hospital before the 10th postoperative day.)

Most patients in this study were discharged within 1 week of their surgeries. A total of 22 patients died, from multiple system organ failure (15), pulmonary failure (4), bowel necrosis (1), pulmonary embolus (1), or myocardial infarction (1). Concentrations of IgM EndoCAb ranged from 9 to 4,946, with a median of 139. The POSSUM preoperative risk scores ranged from 12 to 42, with a median of 18. Lower IgM EndoCAb concentrations predicted increased risk of postoperative complication, independent of POSSUM risk scores, in these patients. Although the study was not designed to show a causal relation between endogenous antiendotoxin antibody concentrations and postoperative morbidity, the findings suggest that endotoxemia may play a role in the development of postoperative complications.