Accuracy and Effectiveness of Point-of-Care Ultrasound for Peripheral Intravenous Access in Emergency and Trauma Patients: A Systematic Review.

Peripheral intravenous (PIV) access is essential in emergency and trauma care, but challenging in patients with difficult intravenous access (DIVA). This systematic review evaluates the accuracy and effectiveness of point-of-care ultrasound (POCUS)-guided PIV access compared to conventional landmark techniques in emergency and trauma patients. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic search of PubMed/MEDLINE, Scopus, Web of Science, and Embase was conducted for studies published between January 2021 and December 2025 to focus on contemporary operator training and device improvements, while acknowledging potential time-lag bias. Randomized controlled trials (RCTs) and comparative observational studies reporting first-attempt success, overall success, time to cannulation, attempts, or complications were included. Two reviewers independently screened studies and extracted data, with conflicts resolved by consensus; inter-rater agreement was calculated where possible. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool and the Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) tool. Nine studies (1,576 participants) met the inclusion criteria: four RCTs, one quasi-experimental, two retrospective cohorts, one prospective observational, and one pilot study. POCUS-guided PIV access significantly improved first-attempt success and overall success (82.4-100% vs. 13.89%, noting the comparator arm may reflect highly selected DIVA patients or less experienced operators) compared to conventional techniques. Fewer attempts were required with POCUS. Time to cannulation was measured from skin contact to successful insertion, including multiple attempts, and was operator- and setup-dependent. Complication rates were comparable or lower with POCUS (definitions included infiltration, extravasation, arterial puncture, and infection; follow-up duration was specified in each study). POCUS approach considered standardized measurement (short-axis vs. long-axis) and vein depth; vessels ≥3.5 mm predicted higher success (OR 2.88, 95% CI 1.39-5.96). Training programmes involved nurses, residents, and attendings; competency was objectively assessed, with some studies using cumulative sum (CUSUM) analysis, and proficiency was achieved after a median of 11 insertions, with post-credentialing success >90% and reduced midline catheter utilization. Outcomes were prospectively measured, minimizing institutional practice drift. Risk of bias was low in five studies, moderate in two, and low/some concerns in two RCTs. POCUS-guided PIV access significantly improves success rates and reduces attempts in emergency and trauma patients with difficult access, with a favourable safety profile. Training diverse operators achieves high proficiency and reduces invasive device use. Findings support routine POCUS use for DIVA patients in acute care settings.