Cristina Rincón

Saccharomyces cerevisiae Fungemia: An Emerging Infectious Disease

BACKGROUND Saccharomyces cerevisiae is well known in the baking and brewing industry and is also used as a probiotic in humans. However, it is a very uncommon cause of infection in humans. METHODS During the period of 15-30 April 2003, we found 3 patients with S. cerevisiae fungemia in an intensive care unit (ICU). An epidemiological study was performed, and the medical records for all patients who were in the unit during the second half of April were assessed. RESULTS The only identified risk factor for S. cerevisiae infection was treatment with a probiotic containing Saccharomyces boulardii (Ultralevura; Bristol-Myers Squibb). This probiotic is used in Europe for the treatment and prevention of Clostridium difficile-associated diarrhea. The 3 patients received the product via nasograstric tube for a mean duration of 8.5 days before the culture result was positive, whereas only 2 of 41 control subjects had received it. Surveillance cultures for the control patients admitted at the same time did not reveal any carriers of the yeast. Strains from the probiotic capsules and the clinical isolates were identified as S. cerevisiae, with identical DNA fingerprinting. Discontinuation of use of the product in the unit stopped the outbreak of infection. A review of the literature identified another 57 cases of S. cerevisiae fungemia. Overall, 60% of these patients were in the ICU, and 71% were receiving enteral or parenteral nutrition. Use of probiotics was detected in 26 patients, and 17 patients died. CONCLUSIONS Use of S. cerevisiae probiotics should be carefully reassessed, particularly in immunosuppressed or critically ill patients.

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.

A Randomized and Prospective Study of 3 Procedures for the Diagnosis of Catheter-Related Bloodstream Infection without Catheter Withdrawal

BACKGROUND Suspicion of catheter-related bloodstream infection (CR-BSI) leads frequently to unnecessary catheter withdrawals, and many catheter-tip cultures yield negative results. The objective of this study was to compare the yield of 3 microbiological procedures to assess CR-BSI without catheter withdrawal. METHODS The study was prospectively performed in a group of patients without neutropenia or blood disorders who were admitted to the intensive care unit during a 37-month period with sepsis suspected on clinical grounds and who had central venous catheters inserted for >48 h. The microbiological procedures compared were semiquantitative cultures from hub and skin (superficial), differential quantitative blood cultures, and differential time to positivity between cultures of blood obtained from catheter hubs and peripheral blood. RESULTS Of the 204 episodes of suspected CR-BSI included in the study, 28 were confirmed to be CR-BSI. We obtained the following results for sensitivity, specificity, positive and negative predictive values, and accuracy: superficial cultures, 78.6%, 92.0%, 61.1%, 96.4%, and 90.2%, respectively; differential quantitative blood cultures, 71.4%, 97.7%, 83.3%, 95.6%, and 94.1%, respectively; and differential time to positivity, 96.4%, 90.3%, 61.4%, 99.4%, and 91.2%, respectively. CONCLUSIONS CR-BSI can be assessed without catheter withdrawal in patients without neutropenia or blood disorders who have catheters inserted for a short time and are hospitalized in the intensive care unit. Convenience, use of resources, and expertise should determine the technique of choice in different medical contexts. Because of ease of performance, low cost, and wide availability, we recommend combining semiquantitative superficial cultures and peripheral vein blood cultures to screen for CR-BSI, leaving differential quantitative blood cultures as a confirmatory and more specific technique.

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

ObjectiveTo 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. DesignProspective study. SettingHeart surgery intensive care unit. PatientsIntubated heart surgical patients. InterventionsSystematic tracheal aspirate and protected brush catheter cultures of all intubated patients. Measurements and Main ResultsStudied 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. ConclusionsPatients 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.

A needleless closed system device (CLAVE) protects from intravascular catheter tip and hub colonization: a prospective randomized study

Hub colonization and subsequent intraluminal progression due to frequent opening and manipulation of intravenous systems is the cause of many catheter-related infections (CRI). A prospective, comparative, randomized study was performed to assess a new closed-needleless hub device (CLAVE) compared with conventional open systems (COS). End-points were hub and skin colonization, catheter tip colonization, catheter-related bloodstream infection (CRBSI) and number of accidental needlesticks. All cultures were processed following standard semiquantitative microbiological techniques. The study involved patients who underwent heart surgery over an 11-month period in a post-surgical ICU. During the study period, 352 patients underwent major heart surgery and 1774 catheters were inserted. Overall, 865 catheters in 178 patients were allocated to the CLAVE system and 909 catheters in 174 patients to COS. The groups were similar regarding underlying conditions and risk factors for infection. Comparison of endpoint results in CLAVE and COS groups was as follows: incidence density per 1000 catheter-days of tip colonization: 59.2 versus 83.6 (P=0.003); of hub colonization: 7.56 versus 24.66 (P=0.0017); of skin colonization: 41.5 versus 58.9 (P=0.038); and of CRBSI 3.78 versus 5.89 (P=0.4). There was one accidental needlestick and one catheter-related prosthetic endocarditis in the COS group. Multivariate analysis showed that CLAVE use was an independent protective factor for tip colonization. CLAVE offered significant protection from catheter-tip and hub colonization.

Concentration of Bovine Serum Albumin Aqueous Solutions by Membrane Distillation

ABSTRACT The use of membrane distillation in the concentration of protein solutions is proposed. Semidilute BSA solutions (concentrations ranging between 40 and 100%), at pH 7 were employed. Transmembrane volume fluxes and evolution of the BSA concentration were measured at different conditions. Temperatures ranged between 20 and 38°C. The filtration cell was operated at laminar regime with tangential velocities of 579 and 89cm-s°. Special attention was devoted to analysis of the temperature polarization and fouling effects. The results obtained show that fouling effects are practically absent in membrane distillation operations with BSA solutions, at least for concentrations up to 10% w/w and in the range of crossflow velocities employed. This may be due to the fact that the transmembrane fluxes are below the value of the critical flux for fouling.

Separation of water and glycols by direct contact membrane distillation

Abstract In the present paper the feasibility of using direct contact membrane distillation for the concentration of glycol from used coolant liquids is analyzed. Membrane distillation experiments were performed with water–ethylene glycol mixtures, using a tangential flow cell, various membranes and different temperatures. The experiments show that the membranes reject almost completely the glycol and effective concentration is achieved. This result is expected, since the vapor pressure of glycol is negligible, compared to that of water, at the temperatures employed in the experiments. On the other hand, the effects of both temperature and concentration polarization were very important, and a specific computer code was developed in order to take them into account. From the computer code, values are obtained for the permeability of the membrane, and for the heat and mass transfer coefficients of the boundary layers. The values obtained agree with those of other literature sources and with the theoretical expectations.

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

A prevalence survey of intravascular catheter use in a general hospital

Purpose Survey of intravascular catheter management is an essential step in the control and prevention of catheter-related infection. In recent years, most surveillance studies only included catheters from intensive care units (ICUs). Data regarding the level of care and adherence to international guidelines in a whole general institution are scarce. Our objective was to evaluate the care situation of intravascular catheters in our adult units of a General Hospital. Methods We surveyed adults hospitalized in non-psychiatric/maternity wards. In a week, a nurse visited all the adult hospitalized patients. Data were registered in a protocol that included variables, such as no. of catheters, location of catheter, type of catheter, date of placement and the need of an indication of each catheter in the visit day. Results We included in the study a total of 753 adult patients. Of them, 653 (86.7%) had one or more inserted catheters at the moment of the study visit (total: 797 catheters). Of all the catheters, 144 (18.0%) were central venous catheters and 653 (81.9%) were peripheral lines. The hospitalization units where the patients were admitted were ICU, 52 (6.9%); and non-ICU, 601 (92.0%). There were 183 (22.9%) catheters with no need to remain in place in the day of the study. Overall, we found 464 (71.0%) patients with one or more opportunities for catheter care improvement. Conclusions A rapid survey of the care situation of intravascular catheters is feasible and easy to do with our methodology. The data show great opportunity for improvement, mainly in the non-ICU areas.

Erratum to: ‘Effectiveness of a training program in compliance with recommendations for venous lines care’

Financial support M. Guembe is supported by the Miguel Servet Program (ISCIII-MICINN, CP13/00268) from the Health Research Fund (FIS), of the Carlos III Health Institute (ISCIII), Madrid Spain, partially financed by the by the European Regional Development Fund (FEDER) “A way of making Europe”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.