Infecções de sítio cirúrgico após cirurgias cardíacas em um hospital universitário mineiro: incidência, aspectos microbiológicos e epidemiológicos

Abstract

Surgical site infections (SSI) after cardiac surgery is a significant problem for patients operated in terms of morbidity, mortality and costs. The objective of this study was to investigate epidemiological aspects of these infections in the main types of heart surgeries, including incidence, etiology, pathogenesis and risk factors of nosocomial infection, divided into ISC and other anatomical sites and hospital mortality in adult patients. We conducted a study case vs. control in patients undergoing cardiac surgery between November 2005 and August 2009. The most common surgical procedure was coronary artery bypass grafting (CABG) (53%), followed by surgery to repair valve (CRV) (25.2%), other surgeries (14.7%) and surgery combined CRM and CRV (6.9%). The rate of surgical site infection was 17.6%, with almost two thirds of patients diagnosed before hospital discharge. The ISC site infections were detected in 65 (14.5%) patients and organ/space in 10 patients (2.2%). The following independent risk factors were associated with the development of CSI: Body Mass Index (BMI) &#8805; 30 kg/m2 (OR: 2.20, 95% CI 1.16 to 4.16, P = 0.0154), Risk index for surgical site infection "2" (IRIC) (OR: 1.81, 95% CI 1.00 to 3.29, P = 0.0506), CABG (OR: 2.36; 95% CI 1.22 to 4.58, P = 0.0109), postoperative hospitalization greater than 7 (seven) days (OR: 3.60, 95% CI 1.70 to 7.66, P = 0,0008). The nasal colonization prior patient with S. aureus, was also a predisposing factor (13.7% vs. 0% in the control group, P = 0.0011) only when the analysis. The rate of nosocomial infection episodes observed in other sites including the blood stream (CS) and urinary tract infection (UTI) and lungs (pneumonia), considered as a group exceeded (68.6%) of the ISC (31.3% ) with a ratio of 2.1 for each ISC These infections in other anatomical sites presented as independent risk factors for co-morbidity renal failure (OR: 3.55, 95% CI 2.00 to 6.32, P = <0.0001) and postoperative hospitalization longer than 7 (seven) days (OR: 5.76, 95% CI 2.93 to 11.33, P<0.0001). Microbiological criteria were used in the diagnosis of the majority of SSI (52.0%) and other IHS (59.0%), highlighting a predominance of gram-negative bacilli (GNB) (63.5%), absent in the air the operating room, Klebsiella spp. (24.1%) and Staphylococcus aureus (20.6%) as the most common pathogens. Microorganisms multidrug resistant (66.3%) predominated among the isolates recovered from clinical specimens. Mortality was significant both in patients with SSI (OR: 3.09, 95% CI 1.26 to 7.59, P<0.0134) and in those with severe infections like PNM and infections of CS (P<0, 05). Although the ISC, which are common in hospital practice, are increasingly recognized as a measure of quality of care offered to patients, more significant results in terms of morbidity, mortality, and therefore costs, especially when the inclusion of infections in other anatomical sites after cardiac surgery, as observed in this study, should be examined critically.