Objective: The aim of this study was to prospectively evaluate frequency, characteristics, and predictors of nosocomial infections (NI) in a tertiary care centre.
Methods: Study population included 925 patients (mean age 62.3+/-12.5, 32.3% females, 22.9% diabetics, 6.8% with previous cardiac procedures) operated on between June 2005 and December 2006 (CABG 48.72%, valvular procedures 30.05%, thoracic aortic 10.9%, heart transplantations 3.78% and miscellanea 6.55%, procedure status: elective 72.9%, urgent 15.9% and emergent 11.2%). The study population was divided in two groups according to development of NI. Primary endpoints were multiorgan failure (MOF) and hospital mortality in the two groups. Secondary endpoints were length of intubation, intensive care unit (ICU) stay and overall hospitalisation. Univariate and multivariate analysis of NI predictors was conducted between 115 perioperative variables.
Results: Eighty-three patients (9%) developed a NI. Infections affected respiratory tract in 51.8%, blood stream in 20.5 and wound infection in 27.7 (13.3% deep wound). Staphylococcal species (60.6%) predominated in blood stream and surgical wound infections while Gram-negative species predominated in respiratory infections. Patients affected by NI experienced significantly higher incidence of MOF (12% vs 0.8%) and hospital mortality (24.1 vs 6.9%). Development of NI significantly lengthened all the steps of postoperative process of care (length of intubation: 49.9+/-73 h vs 19.1+/-35.2; ICU stay: 10.4+/-12.8 days vs 3.4+/-4.6 and hospitalisation 20.7+/-15.3 vs 10.6+/-7). Independent predictors of NI were immunosuppressive therapy [OR 12.9 (CI 5.07-31.2)], reintubation [OR 10.3 (CI 4.6-2.3)], stroke [OR 9.5 (CI 1.8-49)], resternotomy for bleeding [OR 6.7 (CI 1.9-23.6)], emergent/urgent status [OR 3.6 (CI 1.5-8.4)], CVVH [OR 3.2 (CI 1.4-7.5)] and length of intubation [OR 1.03 (CI 1.01-1.1)].
Conclusions: NI still represents a serious complication. Presence of identified determinants of NI should prompt modification of management algorithms.