Use of real-time ultrasound guidance for the placement of hemodialysis catheters: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Insertion of percutaneous hemodialysis catheters is an invasive procedure with a small but definite risk of morbidity and mortality. OBJECTIVES: Assessing potential benefits of using real-time 2-dimensional Doppler ultrasound imaging guidance for the insertion of hemodialysis catheters compared with insertion based solely on anatomic landmarks. STUDY DESIGN: Systematic review and meta-analysis of randomized controlled trials. DATA SOURCES: MEDLINE (1966 to July 2010), EMBASE (1980 to July 2010), Cochrane Renal Group Specialised Register, and Cochrane Central Register of Controlled Trials (CENTRAL). SETTING & POPULATION: Patients requiring hemodialysis catheter insertion. SELECTION CRITERIA FOR STUDIES: We included all randomized controlled trials regardless of publication status or language. INTERVENTIONS: Real-time 2-dimensional Doppler ultrasound image guidance. OUTCOMES: Catheter placement failures, catheters failed to be placed in the first attempt, attempts per catheter inserted, time taken for successful venous puncture, and complications (carotid artery puncture, pneumo- or hemothorax, neck hematoma, and brachial plexus injury). Treatment effects were summarized with the RR measure for dichotomous outcomes and mean difference for continuous outcomes. RESULTS: 7 trials with 830 catheters were identified. Ultrasound guidance significantly decreased the risk of the following outcomes: catheter placement failure (7 studies, 830 catheters; RR, 0.12; 95% CI, 0.04-0.37), failure to place catheter on first attempt (5 studies, 595 catheters; RR, 0.40; 95% CI, 0.29-0.56), arterial punctures (6 trials, 785 catheters; RR, 0.22; 95% CI, 0.06-0.81), and hematoma formation (4 trials, 323 catheters; RR, 0.27; 95% CI, 0.08-0.88). It also significantly decreased the time to cannulate the vein (1 trial, 73 catheters; mean difference, -1.40; 95% CI, -2.17 to -0.63), and number of attempts per catheter insertion (1 trial, 110 catheters; mean difference, -0.35; 95% CI, -0.54 to -0.16). LIMITATIONS: Only 7 studies were identified, of which 3 were reported in only a conference abstract form. Some outcomes were reported in only 1 study. CONCLUSIONS: Use of real-time Doppler ultrasound guidance has benefits with respect to several important clinical outcomes, and its routine use in the insertion of hemodialysis catheters is strongly recommended.

Ultrasound use for the placement of haemodialysis catheters.

BACKGROUND: A significant proportion of patients starting dialysis do so with a temporary or tunnelled haemodialysis catheter. Insertion of these catheters can be achieved either by using the anatomical landmarks for the veins into which they are inserted or using ultrasound guidance. It has been suggested that the use of ultrasound guidance reduces the immediate complications of haemodialysis catheter insertions such as pneumothorax or arterial puncture. OBJECTIVES: The aim of the review was to compare the use of real-time 2-dimensional (2-D) Doppler ultrasound venous imaging in the insertion of percutaneous central venous catheters for dialysis versus the traditional "blind" landmark method. SEARCH METHODS: We searched the Cochrane Renal Group's Specialised Register, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL). Reference lists of identified studies and relevant narrative reviews were also screened. Search date: January 2011. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs evaluating ultrasound guidance in the percutaneous insertion of central venous catheters for dialysis (both cuffed and uncuffed) against the traditional blind landmark method. DATA COLLECTION AND ANALYSIS: Two authors assessed risk of bias and extracted data. Statistical analyses were performed using the random effects model and the results expressed as risk ratios (RR) for dichotomous outcomes or mean difference (MD) for continuous data with 95% confidence intervals (CI). MAIN RESULTS: We identified seven studies enrolling 767 patients and with 830 catheter insertions. Three of seven studies described the method of random sequence generation, none described allocation concealment, and blinding of participants and personnel was not possible. Real-time ultrasound guidance was found to significantly reduce the risk of catheter placement failure on the first attempt (5 studies, 595 catheters): RR 0.40, 95% CI 0.30 to 0.52), significantly reduce the risk of arterial puncture (6 studies, 535 catheters: RR 0.13, 95% CI 0.04 to 0.37) and haematomas (4 studies, 323 catheters: RR 0.22, 95% CI 0.06 to 0.81) when compared to the landmark method. The time taken for successful cannulation was significantly lower with the use of real-time ultrasound guidance (1 study, 73 catheters: MD -1.40 min, 95% CI -2.17 to -0.63) and there were less attempts/catheter insertion (1 study, 110 catheters: -0.35, 95% CI -0.54 to -0.16). AUTHORS' CONCLUSIONS: Use of real-time 2-D Doppler ultrasound guidance has significant benefits with respect to the number if catheters successfully inserted on the first attempt, reduction in the risk of arterial puncture and haematomas and the time taken for successful vein puncture.

Systematic review of antimicrobials for the prevention of haemodialysis catheter-related infections.

BACKGROUND: Almost 30% of chronic haemodialysis (HD) patients are dependent on central venous catheters (CVCs) for their vascular access, and catheter-related bacteraemia (CRB) is the major reason for catheter loss and has been associated with substantial morbidity, including meta-static infections. This systematic review evaluates the benefits and harms of antimicrobial interventions for the prevention of catheter-related infections (CRIs). METHODS: MEDLINE (1950-May 2009), EMBASE (1980-May 2009) CENTRAL (up to May 2009) and bibliographies of retrieved articles were searched for relevant RCTs. Analysis was by a random effects model and results expressed as rate ratio, relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI). RESULTS: A total of 29 trials with 2886 patients and 3005 catheters were included. Antimicrobial catheter locks (AMLs) significantly reduced the rates of CRBs (rate ratio, 0.33, 95% CI 0.24-0.45) and exit-site infections (ESIs) (rate ratio 0.67, 95% CI 0.47-0.96). Exit-site antimicrobial application also significantly reduced the rates of CRBs (rate ratio 0.21, 95% CI 0.12-0.36) and ESIs (rate ratio 0.22, 95% CI 0.10-0.47). Antimicrobial coating of HD catheters and the use of peri-operative antimicrobials did not result in significant reduction in rates of CRBs and ESIs. CONCLUSION: The use of AMLs and exit-site antimicrobials are useful measures in the reduction of CRIs, whereas antimicrobial impregnated catheters and peri-operative systemic antimicrobial administration have not been found to be beneficial. Further head-to-head trials of various AMLs and exit-site antimicrobials are needed to know about their comparative clinical efficacy.