Ethanol lock therapy (E-Lock) in the prevention of catheter-related bloodstream infections (CR-BSI) after major heart surgery (MHS): a randomized clinical trial.

BACKGROUND: Lock-therapy with antimicrobials has been used for the treatment and prevention of catheter-related bloodstream infections (CR-BSI). Experiences with Ethanol-Locks (E-locks) have included therapeutic interventions with variable results. Patients undergoing Major Heart Surgery (MHS) are a high-risk population for CR-BSI.The aim of this study was to assess the efficacy and tolerance to E-Locks in the prevention of CR-BSI of patients undergoing MHS. METHODS AND FINDINGS: This is an academic, prospective, randomized, non-blinded and controlled clinical trial assessing the incidence of CR-BSI of patients with E-locks (E-lock) and the tolerance to the procedure in comparison with patients receiving conventional catheter-care (CCC). Patients undergoing MHS with intravascular catheters for more than 48 hours were randomly assigned into treatment or control group by a computer-generated list of randomly assigned numbers. In the treatment group, all their catheter lumens were locked with an ethanol solution at 70% for two hours, every three days (E-Locks). The control group received conventional catheter-care (CCC). Overall, 200 patients with 323 catheters were included in the study, which was stopped after 10 months due to adverse events. Of them, 179 catheters (113 patients) had E-Locks and 144 catheters (87 patients) were CCC. Euroscore Surgical Risk in both groups was 4.04 vs 4.07 p = 0.94 respectively. The results for the E-Locks and CCC were as follows: Incidence of CR-BSI/1000 days of exposure 2.1 vs 5.2 (p = 0.33), catheter tip colonization 14 (7.8%) vs 6 (4.2%) patients (p = 0.17), median length of hospital stay, 15 vs 16 days (p = 0.77). Seven patients (6.19%), all in the ethanol branch, had to discontinue the trial due to intolerance or adverse events. CONCLUSIONS: We do not recommend prophylaxis of CR-BSI with ethanol-lock on a routine basis in patients undergoing Major Heart Surgery. TRIAL REGISTRATION: Clinical Trials.gov NCT01229592.

Impact of four sequential measures on the prevention of ventilator-associated pneumonia in cardiac surgery patients.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is the most frequent infection in patients admitted to intensive care units. METHODS: We compared rates of VAP, days on mechanical ventilation (MV), and cost of antimicrobial agents before and during implementation. RESULTS: We collected data from 401 patients before the intervention and from 1,534 patients during the intervention. Both groups were comparable. No significant differences in EuroSCORE were observed between the patients of both periods (6.4 versus 6.3; P = 0.7). The rates of VAP (episodes/1,000 days of ventilation) were, respectively, 23.9 versus 13.5 (P = 0.005). Mean number of days of MV/1,000 days of stay was 507 versus 375 (P = 0.001), and the cost of antimicrobial therapy (Euros/1,000 days of stay) was €70,612 versus €52,775 (P = 0.10). The main effect of sequential application of preventive measures in time achieved a relative-rate reduction of VAP of 41% (IRR, 0.41; 95% CI, 0.28 to 0.62). The mortality rate before and during the intervention was 13.0% and 10.2%, respectively. CONCLUSIONS: A sequentially applied bundle of four preventive measures reduces VAP rates, days of MV, and the cost of antimicrobial therapy in patients admitted to the major heart surgery ICU. TRIAL REGISTRATION: Clinical Trials.gov: NCT02060045. Registered 4 February 2014.

Continuous aspiration of subglottic secretions in the prevention of ventilator-associated pneumonia in the postoperative period of major heart surgery.

OBJECTIVE: Aspiration of endotracheal secretions is a major step in the prevention of ventilator-associated pneumonia (VAP). We compared conventional and continuous aspiration of subglottic secretions (CASS) procedures in ventilated patients after major heart surgery (MHS). MATERIALS AND METHODS: Randomized comparison during a 2-year period. RESULTS: A total of 714 patients were randomized (24 patients were excluded from the study; 359 CASS patients; 331 control subjects). The results for CASS patients and control subjects (per protocol and intention-to-treat analysis) were as follows: VAP incidence, 3.6% vs 5.3% (p = 0.2) and 3.8% vs 5.1%, respectively; incidence density, 17.9 vs 27.6 episodes per 1,000 days of mechanical ventilation (MV) [p = 0.18] and 18.9 vs 28.7 episodes per 1,000 days of MV, respectively; hospital antibiotic use in daily defined doses (DDDs), 1,213 vs 1,932 (p < 0.001) and 1,392 vs 1,932, respectively (p < 0.001). In patients who had received mechanical ventilation for > 48 h, the comparisons of CASS patients and control subjects were as follows: VAP incidence, 26.7% vs 47.5% (p = 0.04), respectively; incidence density, 31.5 vs 51.6 episodes per 1,000 days of MV, respectively (p = 0.03); median length of ICU stay, 7 vs 16.5 days (p = 0.01), respectively; hospital antibiotic use, 1,206 vs 1,877 DDD (p < 0.001), respectively; Clostridium difficile-associated diarrhea, 6.7% vs 12.5% (p = 0.3), respectively; and overall mortality rate, 44.4% vs 52.5% (p = 0.3), respectively. Reintubation increased the risk of VAP (relative risk [RR], 6.07; 95% confidence interval [CI], 2.20 to 16.60; p < 0.001), while CASS was the only significant protective factor (RR, 0.40; 95% CI, 0.16 to 0.99; p = 0.04). No complications related to CASS were observed. The cost of the CASS tube was 9 vs 1.5 euro for the conventional tube. CONCLUSIONS: CASS is a safe procedure that reduces the use of antimicrobial agents in the overall population and the incidence of VAP in patients who are at risk. CASS use should be encouraged, at least in patients undergoing MHS.

Cultures of sternal wound and mediastinum taken at the end of heart surgery do not predict postsurgical mediastinitis.

The aim of the study was to assess of the role of intraoperative cultures taken at the end of major heart surgery (MHS) in the prediction of postoperative mediastinitis (PM) in patients undergoing MHS over a 6-month period in a tertiary university hospital. Just before wound closure, a sample of the sternal border was taken, swabbing back and forth the sternal border and the subcutaneous tissues. A second sample was taken after irrigation of the deep mediastinal structures with 10 mL of Ringer lactate. Swabs were processed semiquantitatively and the mediastinal fluid with a quantitative technique. The observation of one or more colonies per plate was considered a positive culture. Cultures obtained at the end of 229 surgical interventions (227 patients) were positive with the semiquantitative or with the quantitative procedures in 31.0% (95% confidence interval [CI], 25.1-37.4%) and 34.5% (95% CI, 28.4-41.0%) of the times, respectively (P = NS). The number of microorganisms isolated in the wound swab or mediastinal fluid was 91 and 110, respectively. Of the 227 patients, 7 developed an episode of PM (3.1%; 95% CI, 1.2-6.2%) after a median time of 11 days (range, 5-19 days). The microorganisms causing the 7 cases of mediastinitis were not isolated in the intraoperative cultures in any of the cases. The value of intraoperative cultures as a test for prediction of PM depending on the breakpoint chosen were as follows: sensitivity (0%), specificity (66.2-97.3%), and positive (0%) and negative predictive values (96.8-98.0%). We recommend against surveillance cultures taken intraoperatively in patients undergoing MHS.

The challenge of anticipating catheter tip colonization in major heart surgery patients in the intensive care unit: are surface cultures useful?

OBJECTIVE: Patients undergoing heart surgery show a high risk of catheter colonization and catheter-related bloodstream infections. We evaluated whether skin insertion site and catheter hub surveillance cultures ("surface cultures") could predict catheter colonization and help establish the origin of bloodstream infections. DESIGN: : Prospective cohort study. SETTING: An 11-bed heart surgery intensive care unit in a tertiary university hospital. PATIENTS: Heart surgery patients spending >4 days in intensive care over an 11-month period. INTERVENTIONS: All catheters were surveyed. Cultures were obtained from the skin insertion site and all hubs on day 5 after surgery, every 72 hrs thereafter, and on catheter removal. Swabs were processed semiquantitatively by streaking the surface of a Columbia agar plate. Catheters were processed using Maki's method. The observation of > or = 15 colonies/plate was taken to indicate a positive skin or catheter colonization culture result. MEASUREMENTS AND MAIN RESULTS: Over the study period, 561 catheters were inserted in 130 patients. The median time a catheter was in place was 6 days (interquartile range 3-11), and 3,712 surface cultures were obtained (median four per patient). Catheter colonization occurred in 133 catheters, and there were 15 episodes of catheter-related bloodstream infection (incidence density of colonization 29.3 and of catheter-related bloodstream infection 8.8 per 1,000 catheter-days). Validity indexes for the capacity of surface cultures to predict catheter colonization and catheter-related bloodstream infection, respectively, were as follows: accuracy, 71.4, 65.6; sensitivity, 83.5%, 100%; specificity, 67.1%, 64.7%; positive predictive value, 47.6%, 7.2%; negative predictive value, 91.9%, 100%; positive likelihood ratio, 2.5, 2.83; and negative likelihood ratio, 0.2, 0. Surface cultures correctly predicted 77.4% of all bacteremia episodes (catheter-related and non-catheter-related). CONCLUSIONS: Systematic surveillance cultures of catheter hub and skin insertion sites in patients admitted to a heart surgery intensive care unit could help identify patients who would benefit from decontamination and preventive measures and establish whether catheters are the portal of entry of bloodstream infection.

Ventilator-associated pneumonia after heart surgery: a prospective analysis and the value of surveillance.

OBJECTIVE: To determine the frequency, etiology, and risk factors of ventilator-associated pneumonia (VAP) and purulent tracheobronchitis (TBX) in patients who have undergone heart surgery. To study the predictive role of systematic surveillance cultures. DESIGN: Prospective study. SETTING: Heart surgery intensive care unit. PATIENTS: Intubated heart surgical patients. INTERVENTIONS: Systematic tracheal aspirate and protected brush catheter cultures of all intubated patients. MEASUREMENTS AND MAIN RESULTS: Studied were the frequency of lower respiratory tract infection in ventilated patients and the role of surveillance cultures. The frequency of VAP was 7.87% (34.5 per 1,000 days of mechanical ventilation), and the criteria for purulent tracheobronchitis was fulfilled by 8.15% of patients (31.13 per 1,000 days of mechanical ventilation). After multivariate analysis, the variables independently associated with the development of respiratory tract infection were central nervous system disorder (relative risk [RR] = 4.7), ulcer disease (RR = 3.6), New York Heart Association score >/=3 (RR = 4), need for mechanical circulatory support (RR = 6.8), duration of mechanical ventilation >96 hrs (RR = 12.3), and reintubation (RR = 63.7). Mortality in our study was as follows: VAP patients, 57.1%; purulent tracheobronchitis patients, 20.7%; colonized patients, 11.5%; and noncolonized patients, 1.6%. Regular surveillance cultures were taken from all ventilated patients to assess the anticipative value of the cultures in predicting respiratory tract infection. A total of 1,626 respiratory surveillance samples were obtained. Surveillance cultures effectively predicted only one episode of VAP and one of tracheobronchitis. CONCLUSIONS: Patients undergoing heart surgery have a high frequency of VAP. VAP is associated with a poor prognosis. In this study, surveillance cultures failed as an anticipative diagnostic method.