Prevention of coagulase-negative staphylococcal central venous catheter-related infection using urokinase rinses: a randomized double-blind controlled trial in patients with hematologic malignancies.

PURPOSE: Fibrin deposition at the intraluminal surface of the indwelling part of the central venous catheter (CVC) surface increases the risk of CVC-related coagulase-negative staphylococci (CoNS) infection. Therefore, repetitive enzymatic dissolution of fibrin by urokinase might reduce the risk of CVC-related infection. We undertook this study to investigate whether three times weekly urokinase rinsing of CVC reduces the incidence or severity of CVC-related infections by CoNS in patients undergoing intensive cytotoxic treatment for hematologic malignancies. PATIENTS AND METHODS: In a double-blind setting, all consecutive patients with a CVC were randomly allocated to receive either urokinase rinses (5 mL of 5,000 U/mL) or placebo (saline), both three times weekly. RESULTS: The percentage of patients with at least one positive culture with CoNS was lower in patients receiving urokinase compared with patients receiving placebo (26% v 42%, respectively; relative risk [RR] = 0.61; 95% CI, 0.39 to 0.94). Major CVC-related CoNS infection occurred less frequently in patients receiving urokinase versus placebo (1.2% v 14.1%, respectively; RR = 0.09; 95% CI, 0.01 to 0.50). Secondary complications, including CVC-related thrombosis, were observed less frequently in the urokinase group compared with the placebo group (1.3% v 9.0%, respectively; RR = 0.14; 95% CI, 0.02 to 0.82). No severe bleeding complications attributable to urokinase were observed. CONCLUSION: Three times weekly urokinase rinsing reduces the incidence of CVC-related CoNS infection in patients treated with intensive cytotoxic therapy for hematologic malignancies, with acceptable safety.

Infectious complications of central venous catheters increase the risk of catheter-related thrombosis in hematology patients: a prospective study.

PURPOSE: We studied whether the risk of central venous catheter (CVC) -related thrombosis increased after an episode of CVC-related infection in patients undergoing intensive chemotherapy. Secondly, we determined whether thrombosis can be predicted or excluded by CVC lock fluid surveillance cultures. PATIENTS AND METHODS: In a prospective setting, 105 consecutive patients were carefully examined for CVC-related infection and thrombosis. In all patients, microbial surveillance cultures of CVC lock fluid were taken every other day. All patients with clinical suspicion of CVC-related thrombosis underwent Doppler ultrasound or additional venography. RESULTS: The cumulative incidence of CVC-related infection was 24% (25 of 105 patients). Clinically manifest thrombosis occurred in 13 (12%) of 105 patients. In patients with CVC-related infection, the risk of thrombosis increased markedly in comparison to those without infection (relative risk, 17.6; 95% CI, 4.1 to 74.1). In patients having two or more positive subsequent CVC lock fluid cultures with identical micro-organisms, 71.4% developed thrombosis, as compared with 3.3% in patients with negative or a single positive culture. CONCLUSION: The risk of clinically manifest thrombosis is increased after an episode of CVC-related infection in patients undergoing intensive chemotherapy. Surveillance culturing of CVC lock fluid may be clinically useful in estimating the risk for thrombosis and the instigation of focused early intervention.

Reduced stem cell mobilization in mice receiving antibiotic modulation of the intestinal flora: involvement of endotoxins as cofactors in mobilization.

Since endotoxins are potent inducers of stem cell mobilization, we hypothesized that their presence in the gut may play a role in cytokine-induced mobilization. To address this possibility we added ciprofloxacin and polymyxin B to the drinking water of Balb/c mice mobilized with either interleukin-8 (IL-8), granulocyte colony-stimulating factor (G-CSF), or flt3 ligand (FL). The yield of colony-forming units (CFUs) was significantly reduced in all mice treated with these antibiotics when compared with controls (IL-8: 192 +/- 61 vs 290 +/- 64, P <.05; G-CSF: 1925 +/- 1216 vs 3371 +/- 1214, P <.05; FL: 562 +/- 213 vs 1068 +/- 528, P <.05). Treatment with ciprofloxacin eliminated only aerobic Gram-negative bacteria from the feces without effect on mobilization. Polymyxin B treatment did not result in decontamination but significantly reduced the number of mobilized hematopoietic progenitor cells (HPCs) most likely due to the endotoxin binding capacity of polymyxin B. More than 90% of the gastrointestinal flora consists of anaerobic bacteria. Elimination of the anaerobic flora by metronidazol led to a significantly reduced number of mobilized HPCs when compared with controls (IL-8: 55 +/- 66 vs 538 +/- 216, P <.05). Germ-free OF1 mice showed a significantly reduced mobilization compared with their wild-type controls (IL-8 controls: 378 +/- 182, IL-8 germ free: 157 +/- 53, P <.05). Finally, we performed reconstitution experiments adding Escherichia coli-derived endotoxins to the drinking water of decontaminated mice. This resulted in partial restoration of the IL-8-induced mobilization (67 +/- 28 vs 190 +/- 98.1, P <.01). Our results indicate that endotoxins serve as cofactors in cytokine-induced mobilization. Modification of the endotoxin content by antibiotic treatment may affect the yield of cytokine-induced mobilization.

No effect of preoperative selective gut decontamination on endotoxemia and cytokine activation during cardiopulmonary bypass: a randomized, placebo-controlled study.

BACKGROUND: Cardiopulmonary bypass predisposes the splanchnic region to inadequate perfusion and increases in gut permeability. Related to these changes, circulating endotoxin has been shown to rise during cardiac surgery, and may contribute to cytokine activation, high oxygen consumption, and fever ("postperfusion syndrome"). To a large extent, free endotoxin in the gut is a product of the proliferation of aerobic gram-negative bacteria and may be reduced by nonabsorbable antibiotics. OBJECTIVE: To evaluate the effect of preoperative selective gut decontamination (SGD) on the incidence of endotoxemia and cytokine activation in patients undergoing open heart surgery. DESIGN: Prospective, randomized, placebo-controlled double-blind trial. SETTING: Tertiary-care university teaching hospital. INTERVENTION: Preoperative administration for 5 to 7 days of oral nonabsorbable antibiotics (polymyxin B and neomycin) vs. placebo. The efficacy of SGD was assessed by culture of rectal swabs. PATIENTS: Forty-four patients (median age 65 yrs, 29 males) were included in a pilot study to establish the sampling points of perioperative measurements. Seventy-eight consecutive patients (median age 65 yrs, 55 males) were enrolled for the prospective study; of these, 51 were randomly allocated to take SGD (n = 24) or placebo (n = 27); 27 were included in a control group (no medication). MEASUREMENTS AND RESULTS: SGD but not placebo effectively reduced the number of rectal swabs that grew aerobic gram-negative bacteria (27% vs. 93%, respectively; p < .001). SGD did not affect the occurrence of perioperative endotoxemia, nor did it reduce the tumor necrosis factor-alpha, interleukin-10, or interleukin-6 concentrations (p > .20), as determined before surgery, upon aorta declamping, 30 mins into reperfusion, or 2 hrs after surgery. Also, SGD did not alter the incidence of postoperative fever or clinical outcome measures such as duration of artificial ventilation and intensive care unit and hospital stay. CONCLUSION: SGD effectively reduces the aerobic gram-negative bowel flora in cardiac surgery patients but fails to affect the incidence of perioperative endotoxemia and cytokine activation during cardiopulmonary bypass and the occurrence of a postperfusion syndrome.