Efficacy of a needle-free blood collection device (PIVO Pro) for avoiding contaminated blood culture sets in Australian emergency departments: protocol for an adaptive group sequential randomised controlled trial.

introductionBlood cultures are essential for diagnosing bloodstream infections and guiding antimicrobial therapy, but sample contamination can influence test sensitivity and treatment decision-making. The 'PIVO Pro' is a needle-free device which allows blood collection from a peripheral intravenous catheter (PIVC), with its use potentially avoiding sample contamination and decreasing the amount of venepuncture instances. However, existing evidence is limited and rigorous trial data are needed. Our primary objective is to compare the efficacy of the PIVO Pro at PIVC insertion for avoiding blood culture contamination to standard practice (typically specimen collection via venepuncture or a newly inserted PIVC). METHODS AND ANALYSIS: The PIVO Trial is a multicentre, adaptive group sequential randomised controlled trial. Across four Australian emergency departments, an estimated sample of 1148 adults (≥18 years) with a blood culture request, who also require a ≥22-gauge PIVC, will be included. Patients receiving intravenous antimicrobials prior to sample collection will be excluded. Randomisation will be 1:1 to PIVO Pro (one set of blood cultures drawn using PIVO Pro on PIVC insertion, subsequent sets drawn via venepuncture) or control (standard practice for all blood culture sets). The primary outcome is contamination (yes/no) in the target blood culture specimens (with all positive cultures independently assessed by blinded reviewers and classified as contaminated or 'true positive'). Secondary outcomes include bottle underfill (assessed using blinded pathology processes), culture quality (composite of non-contamination and adequate fill) and rate of antibiotic use. The primary estimand compares contamination rates between arms using the PIVO-collected or first PIVC-drawn set from the initial collection episode (target sets), under a treatment-policy strategy, estimated using log-binomial regression. The design accommodates an interim analysis at 2/3 of planned total information. Recruitment commenced in August 2025. ETHICS AND DISSEMINATION: Ethics approval was obtained from Metro North Health Human Research Ethics Committee. Results will be disseminated via peer-reviewed publication and conference presentations. TRIAL REGISTRATION NUMBER: NCT06806709, 4 January 2025, https://clinicaltrials.gov/study/NCT06806709 PROTOCOL VERSION: V.1.5, August 2026.