Multivariate analysis of successful intravenous line placement in the prehospital setting

Intravenous (IV) line placement is an important prehospital advanced life support skill, but IV success rates are variable among providers. Little is known about what factors are associated with successful IV placement, limiting the ability to develop benchmarks for skill maintenance, such as requiring a specific number of IV placements per year.

We aimed to identify whether first-pass IV success was associated with the number of attempted or successful previous IV attempts. We hypothesized that IV success is associated with the number of successful IV placements in the preceding year.

We retrospectively studied 800 consecutive charts with an IV attempt from 11 suburban and rural emergency medical services (EMS) agencies over a one-month period. Cases involving pediatric patients (age <18 years) and those with incomplete data were excluded. Success of the first IV attempt was identified. Potential predictor variables were collected and analyzed by univariate logistic regression, including patient age, systolic blood pressure, history of IV drug abuse or renal disease, traumatic event, catheter size, and location of IV attempt, as well as the individual provider's numbers of total and successful IV attempts in the preceding year. Variables significantly associated with IV success at the p < 0.10 level were included in a multivariate regression model using a p-value of 0.05.

Of 602 cases meeting the study criteria, 469 (77.9%) had a successful first-pass IV placement. Significantly associated with IV success in the univariate regression were patient age (p = 0.054), trauma (p = 0.074), IV catheter size (p < 0.001), IV location (p = 0.056), and the number of previous successful IV attempts (p = 0.039), whereas the number of total previous IV attempts was not significantly associated (p = 0.871). In the multivariate logistic regression model, only IV catheter size had a significant association (p < 0.001), with a larger-bore IV catheter size associated with higher success.

In this retrospective study, larger IV catheter size, but not the prehospital providers' previous year's experience, was associated with successful IV placement in adult patients. These data fail to support requirements for a minimum number of yearly IV placements by full-time paramedics to improve success rates.