Active polymers containing Lactobacillus curvatus CRL705 bacteriocins: effectiveness assessment in Wieners.

Bacteriocins from lactic acid bacteria have potential as natural food preservatives. In this study two active (synthetic and gluten) films were obtained by the incorporation of lactocin 705 and lactocin AL705, bacteriocins produced by Lactobacillus curvatus CRL705 with antimicrobial activity against spoilage lactic acid bacteria and Listeria. Antimicrobial film effectiveness was determined in Wieners inoculated with Lactobacillus plantarum CRL691 and Listeria innocua 7 (10(4)CFU/g) stored at 5°C during 45days. Active and control (absence of bacteriocins) packages were prepared and bacterial counts in selective media were carried out. Visual inspection and pH measurement of Wieners were also performed. Typical growth of both inoculated microorganisms was observed in control packages which reached 10(6)-10(7)CFU/g at the end of storage period. In the active packages, L. innocua 7 was effectively inhibited (2.5 log cycles reduction at day 45), while L. plantarum CRL691 was only slightly inhibited (0.5 log cycles) up to the second week of storage, then counts around 10(6)-10(7)CFU/g were reached. Changes in pH values from 6.3 to 5.8 were produced and gas formation was observed in active and control packages. The low inhibitory effectiveness against lactic acid bacteria is in correlation with the low activity observed for lactocin 705 in the presence of fat; Wieners fat content (20-30%) may adversely affect antimicrobial activity. This study supports the feasibility of using polymers activated with L. curvatus CRL705 bacteriocins to control Listeria on the surface of Wieners and highlights the importance of evaluating antimicrobial packaging systems for each particular food application.

The impact of a nutritional support team on the cost and management of multilumen central venous catheters.

Total parenteral nutrition (TPN) is most commonly delivered into a large vein through a central venous catheter (CVC). Because complications associated with CVCs may be life threatening or costly to the patient and the medical facility, proper care and maintenance of a CVC is essential. A 12-month retrospective study was conducted by a nutritional support team to evaluate cost effectiveness of CVC care in patients receiving TPN. Certain factors, such as catheter type and location, duration of usage, number of catheters, physician who placed the catheter, and complications were recorded for each patient receiving TPN. All CVCs used for TPN were maintained by a member of the nutritional support team. A total of 434 CVCs were placed in 277 patients who required TPN (average, 1.6 catheters/patient; range, 1-10 catheters/patient). Specific catheter-related data, and occurrences of complications were recorded on a flow sheet designed specifically for patients requiring TPN. Major complications (those which potentially increased mortality and morbidity) and minor complications (those that did not prolong hospitalization) were distinguished and the average cost of these complications was determined based on actual patient charges. Major complications occurred in 5% of the catheters placed, including: pneumothorax, thoracic duct fluid leak, artery laceration, malposition, failed attempts, and catheter-related sepsis. Catheter-related sepsis occurred in only 0.5% of patients, compared with a reported incidence of 5%, and cost an average $20,200. Thus, complications of CVC may be reduced when maintenance is provided by a skilled clinician or specific team, decreasing the cost, as well as improving the quality of care.

Nutrition and the use of metabolic assessment in the ventilator-dependent patient.

Nutritional support is an important aspect of care in hospitalized patients, especially those receiving mechanical ventilation. While nutritional assessments can help guide the clinician in determining appropriate caloric intake requirements and refeeding schedules, few tools exist to evaluate the consequences of over- or underfeeding. Metabolic assessment using indirect calorimetry is a new method of nutritional assessment for use at the bedside of the weaning patient. The data obtained from a metabolic assessment can be used to adjust formulas and total caloric intake as well as differentiate between dead space and elevated carbon dioxide production as reasons for persistent hypercarbia.

Clinical evaluation compared to pulmonary artery catheterization in the hemodynamic assessment of critically ill patients.

Although pulmonary artery (PA) catheterization is frequently employed in the management of critically ill patients, there is little documentation that the information obtained alters patient management. This study evaluated prospectively this question in 103 PA catheterizations. Before catheterization, physicians were asked to predict the range of several hemodynamic variables, the presumed diagnosis, and their plan for therapy. After catheterization, each chart was reviewed. The hemodynamics at the time of catheterization and therapy within 8 h of catheterization were noted. Pulmonary artery occlusive (wedge) pressure (WP) was correctly predicted 30% of the time. Cardiac output, systemic vascular resistance (SVR), and right atrial pressure (RAP) were correctly predicted approximately 50% of the time. There was no significant difference in the ability to predict hemodynamics of subgroups with either hypotension or impaired oxygenation. After catheterization, planned therapy was altered in 58% of the cases. Unanticipated therapy was added in 30% of the cases. This study documents the difficulty of predicting accurately hemodynamics based solely on clinical evaluation. Thus, the information obtained by catheterization often leads to alterations in the therapeutic plan. We suggest that PA catheterization is both indicated and useful in the management of critically ill patients.