EARLY BLOOD-STREAM INFECTION AFTER CARDIOPULMONARY BYPASS - FREQUENCYRATE, RISK-FACTORS, AND IMPLICATIONS

Objective: To determine the incidence, predisposing factors, and outco me of early bloodstream infection after cardiopulmonary bypass. Design : A case control study. Setting: A 54-bed cardiac surgical intensive c are in a tertiary referral center. Patients: Patients from a 30-month period with preoperative hospital stay of <48 hrs and subsequent blood stream infection within 96 hrs of cardiopulmonary bypass were included in a case group. The control group consisted of patients who had card iac surgery on the same day as the case group. Measurements and Main R esults: Patient demographics, history of comorbidity, preoperative lab oratory testing, details of surgery, transfusion requirement, inotropi c infusions, hemodynamics, and arterial blood gases on admission to in tensive care were compared in the two groups. Measures of outcome were duration of mechanical ventilation and intensive care stay, serum cre atinine on the first postoperative day, highest creatinine and bilirub in concentrations, and hospital mortality. During the study period, 7, 928 patients had cardiac surgery. Sixteen (0.2%) patients had early bl oodstream infection; the control group consisted of 95 patients. Thirt een of the patients with bloodstream infection had Gram-negative bacil li on blood culture, two had Candida species, and two had Gram-positiv e bacteria. On multivariate logistic regression analysis, greater prev alence of preoperative pulmonary hypertension (odds ratio 9; 95% confi dence interval 2 to 41.8; p =.004), diabetes (adds ratio 4.6; 95% conf idence interval 1.4 to 15.8; p =.01), number of blood products transfu sed (odds ratio 1.09; 95% confidence interval 1.04 to 1.17; p =.005), and infusion of inotropes (odds ratio 4.7; 95% confidence interval 1.3 to 16.4; p =.02) or vasopressors (odds ratio 4.1; 95% confidence inte rval 1.3 to 15.6; p =.02) were associated with postoperative bloodstre am infection. Early bloodstream infection was associated with signific antly prolonged duration of mechanical ventilation (117.2 +/- 21.5 vs. 18 +/- 8.8 hrs; p=.0001), intensive care stay (213 +/- 27.5 vs. 53 +/ - 11.3 hrs; p <.0001), greater creatinine concentrations on the first postoperative day (1.6 +/- 0.1 vs. 1.2 +/- 0.04 mg/dL; p=.0002), great er maximum creatinine concentration (2.4 +/- 0.2 vs. 1.3 +/- 0.1 mg/dL ; p<.0001), and greater maximum bilirubin concentration (4.7 +/- 0.6 v s. 1.3 +/- 0.2 mg/dL; p <.0001) when compared with the control group. Five (32%) of 16 bacteremic patients died vs. none of the 95 control p atients (p <.0001). Conclusions: Early bloodstream infection after car diac surgery is uncommon and involves predominantly Gram negative bact eria. The risk factors associated with bloodstream infection were preo perative morbidity and more complex surgery. Bloodstream infection was associated with a significantly adverse impact on outcome after cardi ac surgery.