Long-term silicone central venous catheters impregnated with minocycline and rifampin decrease rates of catheter-related bloodstream infection in cancer patients: a prospective randomized clinical trial.

PURPOSE: To evaluate the efficacy of long-term nontunneled silicone catheters impregnated with minocycline and rifampin (M-R) in reducing catheter-related bloodstream infections. PATIENTS AND METHODS: This prospective, randomized, double-blind clinical trial was conducted at M.D. Anderson Cancer Center, a tertiary care hospital in Houston, TX. All patients in the trial had a malignancy. RESULTS: Between September 1999 and May 2002, 356 assessable catheters were used: 182 M-R and 174 nonimpregnated. The patients' characteristics were comparable between the two study groups. The mean (+/- standard deviation) duration of catheterization with M-R catheters was comparable to that of nonimpregnated catheters (66.21 +/- 30.88 v 63.01 +/- 30.80 days). A total of 17 catheter-related bloodstream infections occurred during the course of the study. Three were associated with the use of M-R catheters and 14 were associated with the nonimpregnated catheters, with a rate of catheter-related bloodstream infection of 0.25 and 1.28/1,000 catheter-days, respectively (P = .003). Gram-positive cocci accounted for the majority of the organisms causing the infections. There were no allergic reactions associated with M-R catheters. CONCLUSION: Long-term nontunneled central venous catheters impregnated with minocycline and rifampin are efficacious and safe in reducing catheter-related bloodstream infections in cancer patients.

Differential time to positivity: a useful method for diagnosing catheter-related bloodstream infections.

BACKGROUND: Catheter-related bloodstream infections are associated with recognized morbidity and mortality, especially in critically ill patients. Accurate diagnosis of such infections results in proper management of patients and in reducing unnecessary removal of catheters. OBJECTIVE: To evaluate differential time to positivity as a method for diagnosing catheter-related bacteremias caused by both short-term and long-term use of central venous catheters. DESIGN: Prospective study design. SETTING: M.D. Anderson Cancer Center, Houston, Texas, a tertiary care cancer center. PATIENTS: All patients, between September 1999 and November 2000, who had the same organism isolated from blood cultures drawn simultaneously through the central venous catheter and the peripheral vein. MEASUREMENTS: Time necessary for the blood cultures from the central venous catheter and the peripheral vein to become positive, as well as other relevant patient information. RESULTS: 191 bloodstream infections with positive simultaneous central venous catheter and peripheral vein blood cultures were included. One hundred eight patients had catheter-related bacteremias, and 83 had non-catheter-related bacteremias. Catheter-related bacteremias were more frequently caused by staphylococci and less likely to be associated with underlying hematologic malignant conditions, neutropenia, and longer duration of hospitalization. As a diagnostic tool for catheter-related bacteremia (using a composite definition reference standard according to the Infectious Diseases Society of America guidelines), differential time to positivity of 120 minutes or more was associated with 81% sensitivity and 92% specificity for short-term catheters and 93% sensitivity and 75% specificity for long-term catheters. CONCLUSION: Differential time to positivity of 120 minutes or more is highly sensitive and specific for catheter-related bacteremia in patients who have short- and long-term catheters.

Central venous catheter-related bacteremia due to gram-negative bacilli: significance of catheter removal in preventing relapse.

OBJECTIVE: To study the characteristics of catheter-related, gram-negative bacteremia (GNB) and the role of central venous catheter (CVC) removal. DESIGN: This retrospective study involved a search of the microbiological department records of CVC and blood cultures and patients' medical records. SETTING: University of Texas M. D. Anderson Cancer Center, a tertiary-care hospital in Houston, Texas. PATIENTS: Patients with cancer who had catheter-related GNB, defined as (1) a positive catheter tip culture with at least 15 colony-forming units semiquantitatively, (2) isolation of the same organism from the tip and peripheral blood cultures, (3) no other source for bacteremia except the CVC, and (4) clinical manifestations of infection (fever or chills). RESULTS: Between January 1990 and December 1996, 72 cases of catheter-related GNB were available for review. Most of the patients (67; 93%) had their CVCs removed in response to the bacteremia. Few patients (5; 7%) retained their CVCs and were treated with appropriate antibiotics. When CVCs were removed, only 1 patient (1%) relapsed with the same organism, whereas all 5 patients with retained CVCs relapsed after having responded (P < .001). The most commonly isolated organisms were Enterobacter, Klebsiella, Stenotrophomonas, Pseudomonas, and Acinetobacter species. Catheter removal within 72 hours of the onset of the catheter-related GNB was the only independent protective factor against relapse of the infection (odds ratio, 0.13; 95% confidence interval, 0.02-0.75; P = .02). CONCLUSION: In patients with documented catheter-related GNB, CVCs should be removed within 48 to 72 hours to prevent relapse.

Differential quantitative blood cultures for the diagnosis of catheter-related bloodstream infections associated with short- and long-term catheters: a prospective study.

We prospectively evaluated the value of two levels of differential quantitative blood culture (DQBC) ratio (> or =2:1 or > or =5:1) in diagnosing catheter-related bloodstream infections (CRBSIs) in patients with malignancy that have short-term and long-term central venous catheters (CVCs) (<30 and > or =30 days of placement). Diagnosis of CRBSIs was based on results of semiquantitative cultures of removed catheters. For short-term CVCs a 5:1 or greater DQBC ratio had an 18% sensitivity, 67% specificity, 18% positive predictive value (PPV) and 67% negative predictive value (NPV), whereas a 2:1 or greater cut-off point for the DQBC was associated with a 45% sensitivity, 48% specificity, 26% PPV, and 68% NPV for the diagnosis of CRBSIs. For long-term CVCs, a cut-off point of 5:1 or greater of the DQBC had an 81% sensitivity, 40% specificity, 36% PPV, and 83% NPV for the diagnosis of CRBSIa, whereas a 2:1 or greater cut-off point had a 90% sensitivity, 30% specificity, 35% PPV, and 88% NPV for the diagnosis of CRBSIs. In conclusion, DQBCs are not diagnostic of CRBSIs for short-term CVCs. In long-term CVCs, DQBCs at 2:1 or greater or 5:1 or greater are sensitive but associated with low specificity and positive predictive value.