Preoperative carriage and postoperative same-species sternal wound infection after cardiac surgery.

Sternal wound infection (SWI) after cardiac surgery remains an important problem. Prediction of pathogens involved in such infection could guide antibiotics. From April 1, 2006 to December 31, 2008, retrospectively, we evaluated the diagnostic value of preoperative methicillin-sensible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) or multi-drug resistant Gram-negative bacillus (MDRGNB) carriage to predict same-pathogens involved in postoperative SWI. All patients referred for elective cardiac surgery were screened using multisite (nares, axillae, rectal) sampling at admission to detect MSSA, MRSA, and MDRGNB. Of the 1895 patients addressed, 425 patients (22.4%) were colonized at admission. Preoperative carriers more frequently developed SWI than non-carriers, respectively, 11% vs. 5.5% (P<0.05). Because of the small sample, MDRGNB carriers could not be analyzed. For prediction of MSSA SWI with preoperative MSSA carriage, the area under the receiver operating characteristic (ROC) curve was 0.720 (95% confidence interval (CI), 0.364-0.796) and 0.710 (95% CI, 0.623-0.787) for prediction of MRSA SWI with preoperative MRSA carriage. Preoperative MSSA carriage is frequent but preoperative MRSA or MDRGNB carriage remains infrequent. The ability of preoperative carriage to predict a same-pathogen-postoperative SWI was low and should not be used to guide empirical antibiotherapy.

Outcome after valve replacement for severe aortic stenosis associated with reduced left ventricular ejection fraction.

BACKGROUND AND AIM OF THE STUDY: Because valve replacement for aortic stenosis (AS) remains a difficult surgical challenge in the presence of left ventricular dysfunction, the immediate and long-term outcomes, and evolution of left ventricular ejection fraction (LVEF) in this setting, were analyzed. METHODS: Forty-three consecutive patients with severe AS (valve area < or =1 cm2) and reduced LVEF (< or =40%) who underwent valve replacement surgery at the authors' institution between April 1998 and December 2003 and were studied retrospectively. RESULTS: Preoperative characteristics included: LVEF 33 +/- 6%, mean transaortic pressure gradient 46 +/- 13 mmHg, and aortic valve area 0.58 +/- 0.15 cm2. Concomitant coronary artery bypass grafting was performed in 15 patients (35%). Perioperative (30-day) mortality was 2.3%, with 39.5% morbidity. During a mean follow up of 33.4 +/- 17.6 months, eight patients died. The Kaplan-Meier estimate of five-year survival was 75.3%. Postoperatively, none of the survivors remained in NYHA functional classes III-IV. The postoperative LVEF assessed in 81.8% of survivors had improved. Multivariate analysis associated improved LVEF with a higher preoperative mean transaortic pressure gradient (p = 0.0009) and a higher preoperative LVEF (p = 0.02). CONCLUSION: Patients with severe AS and reduced LVEF can undergo valve replacement with low perioperative mortality and moderate postoperative morbidity. Good long-term survival with good NYHA functional status and improved LVEF can be obtained.

Frequency, risk factors, and outcome of hyperlactatemia after cardiac surgery.

STUDY OBJECTIVE: To determine the respective frequencies, risk factors, and outcomes of no hyperlactatemia (NHL), immediate hyperlactatemia (IHL), or late hyperlactatemia (LHL) > 3 mmol/L after cardiac surgery. DESIGN: Prospective and observational study. SETTING: Cardiac surgery ICU in a 130-bed private community nonteaching hospital. PATIENTS: Consecutive patients (n = 325) undergoing cardiopulmonary bypass (CPB) for cardiac surgery. INTERVENTION: None. MEASUREMENTS: Arterial blood gas levels and lactate concentrations were measured at ICU admission, 4 h after surgery, between 6 h and 16 h after surgery, and on day 1. MAIN RESULTS: Sixty-seven patients (20.6%) had an IHL on ICU admission, and 56 patients (17.2%) acquired LHL during their ICU stay. ICU mortality was 1.5% for NHL, 3.6% for LHL, and 14.9% for IHL groups (p < 0.0001). The three groups differed significantly for elective surgery, type of operation, CPB duration, intraoperative mean arterial pressure, and intraoperative and postoperative use of vasopressor. Independent risk factors for IHL were nonelective surgery, CPB duration, and intraoperative use of vasopressor. Logistic regression identified hyperglycemia and epinephrine therapy for LHL as postoperative risk factors. Receiver operating characteristic curves showed that IHL more accurately predicted ICU mortality than LHL. CONCLUSIONS: Hyperlactatemia is common after cardiac surgery. A lactate threshold of 3 mmol/L at ICU admission is able to identify a population at risk of morbidity and mortality after cardiac surgery.