Effect of infusion set replacement intervals on catheter-related bloodstream infections (RSVP): a randomised, controlled, equivalence (central venous access device)-non-inferiority (peripheral arterial catheter) trial.

BACKGROUND: The optimal duration of infusion set use to prevent life-threatening catheter-related bloodstream infection (CRBSI) is unclear. We aimed to compare the effectiveness and costs of 7-day (intervention) versus 4-day (control) infusion set replacement to prevent CRBSI in patients with central venous access devices (tunnelled cuffed, non-tunnelled, peripherally inserted, and totally implanted) and peripheral arterial catheters. METHODS: We did a randomised, controlled, assessor-masked trial at ten Australian hospitals. Our hypothesis was CRBSI equivalence for central venous access devices and non-inferiority for peripheral arterial catheters (both 2% margin). Adults and children with expected greater than 24 h central venous access device-peripheral arterial catheter use were randomly assigned (1:1; stratified by hospital, catheter type, and intensive care unit or ward) by a centralised, web-based service (concealed before allocation) to infusion set replacement every 7 days, or 4 days. This included crystalloids, non-lipid parenteral nutrition, and medication infusions. Patients and clinicians were not masked, but the primary outcome (CRBSI) was adjudicated by masked infectious diseases physicians. The analysis was modified intention to treat (mITT). This study is registered with the Australian New Zealand Clinical Trials Registry ACTRN12610000505000 and is complete. FINDINGS: Between May 30, 2011, and Dec, 9, 2016, from 6007 patients assessed, we assigned 2944 patients to 7-day (n=1463) or 4-day (n=1481) infusion set replacement, with 2941 in the mITT analysis. For central venous access devices, 20 (1·78%) of 1124 patients (7-day group) and 16 (1·46%) of 1097 patients (4-day group) had CRBSI (absolute risk difference [ARD] 0·32%, 95% CI -0·73 to 1·37). For peripheral arterial catheters, one (0·28%) of 357 patients in the 7-day group and none of 363 patients in the 4-day group had CRBSI (ARD 0·28%, -0·27% to 0·83%). There were no treatment-related adverse events. INTERPRETATION: Infusion set use can be safely extended to 7 days with resultant cost and workload reductions. FUNDING: Australian National Health and Medical Research Council.

A comparative assessment of two conservative methods for the diagnosis of catheter-related infection in critically ill patients.

PURPOSE: To assess the utility of two in situ techniques, differential time to positivity (DTP) and semiquantitative superficial cultures (SQSC) for diagnosing catheter-related bloodstream infection (CR-BSI) in critically ill adults. METHODS: This was a prospective cohort study in patients with suspected CR-BSI arising from a short-term arterial catheter (AC) or a central venous catheter (CVC). On suspicion of CR-BSI, devices were removed. Blood, skin, catheter tip and hub cultures were taken. Infection rates were compared against the diagnosis of CR-BSI using matched tip and blood cultures. RESULTS: Of 120 episodes of clinically suspected CR-BSI in 101 patients examined, 9 (7.5 %) were confirmed as CR-BSI. Validity values (95 % CI) for the diagnosis of CR-BSI arising from both AC and CVC for DTP were: sensitivity 44 % (15-77 %), specificity 98 % (93-100 %), positive predictive value (PPV) 67 % (24-94 %), negative predictive value (NPV) 96 % (90-98 %), positive likelihood ratio (LR+) 25 (5-117), negative likelihood ratio (LR-) 0.6 (0.3-1.0), diagnostic odds ratio (DOR) 44 (7-258), and accuracy 94 % (92-98 %). Validity values (95 % CI) for SQSC were: sensitivity 78 % (41-96 %), specificity 60 % (50-69 %), PPV 14 % (6-26 %), NPV 97 % (89-99 %), LR+ 1.9 (1.0-2.3), LR- 0.4 (0.1-1.3), DOR 5.1 (1.1-19), and accuracy 61 % (51-69 %). DTP combined with SQSC improved sensitivity and NPV to 100 % whilst the DOR increased to 25.8 (95 % CI 3-454). CONCLUSIONS: CR-BSI can be ruled out by undertaking DTP and SQSC concurrently for both ACs and CVCs with 100 % sensitivity and NPV.

Routine versus clinically indicated replacement of peripheral intravenous catheters: a randomised controlled equivalence trial.

BACKGROUND: The millions of peripheral intravenous catheters used each year are recommended for 72-96 h replacement in adults. This routine replacement increases health-care costs and staff workload and requires patients to undergo repeated invasive procedures. The effectiveness of the practice is not well established. Our hypothesis was that clinically indicated catheter replacement is of equal benefit to routine replacement. METHODS: This multicentre, randomised, non-blinded equivalence trial recruited adults (≥18 years) with an intravenous catheter of expected use longer than 4 days from three hospitals in Queensland, Australia, between May 20, 2008, and Sept 9, 2009. Computer-generated random assignment (1:1 ratio, no blocking, stratified by hospital, concealed before allocation) was to clinically indicated replacement, or third daily routine replacement. Patients, clinical staff, and research nurses could not be masked after treatment allocation because of the nature of the intervention. The primary outcome was phlebitis during catheterisation or within 48 h after removal. The equivalence margin was set at 3%. Primary analysis was by intention to treat. Secondary endpoints were catheter-related bloodstream and local infections, all bloodstream infections, catheter tip colonisation, infusion failure, catheter numbers used, therapy duration, mortality, and costs. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12608000445370. FINDINGS: All 3283 patients randomised (5907 catheters) were included in our analysis (1593 clinically indicated; 1690 routine replacement). Mean dwell time for catheters in situ on day 3 was 99 h (SD 54) when replaced as clinically indicated and 70 h (13) when routinely replaced. Phlebitis occurred in 114 of 1593 (7%) patients in the clinically indicated group and in 114 of 1690 (7%) patients in the routine replacement group, an absolute risk difference of 0·41% (95% CI -1·33 to 2·15%), which was within the prespecified 3% equivalence margin. No serious adverse events related to study interventions occurred. INTERPRETATION: Peripheral intravenous catheters can be removed as clinically indicated; this policy will avoid millions of catheter insertions, associated discomfort, and substantial costs in both equipment and staff workload. Ongoing close monitoring should continue with timely treatment cessation and prompt removal for complications. FUNDING: Australian National Health and Medical Research Council.