P2.116: A Comparison of Infusion Rates for Indwelling Arterial Catheters in Infants in the PICU

Background: Arterial catheterization is a critical procedure in pediatric intensive care units (PICUs), enabling continuous arterial pressure monitoring and vascular access. Maintaining catheter patency and function remains challenging due to risks such as thrombosis, occlusion, leakage and ischemic injury. Previous findings suggest that infusion rates and catheter gauge size significantly impact catheter longevity and function, influencing complications and overall patient outcomes. In pediatric patients, excessive fluid administration poses additional risks, particularly in post-operative cardiac patients requiring fluid restriction. Despite the widespread use of infusion rates ranging from 0.5 mL/hr to 3 mL/hr in clinical settings, there is limited evidence to guide best practices. This study evaluates the impact of infusion rates on arterial catheter function by assessing catheter longevity, arterial line complications, ease of flushing and withdrawing blood, and blood pressure measurement accuracy.

Methods: In this randomized study, infants aged 3 years and younger admitted to the Montreal Children’s Hospital PICU who required intra-arterial catheterization between 2003 and 2018 were assigned to receive either 0.5 mL/hr or 2.0 mL/hr of heparinized saline through 22G or 24G arterial catheters. Catheter function was assessed every 12 hours, and data were collected on longevity, complications, and overall arterial line function. Outcomes were analyzed using chi-squared or Fisher's exact tests for categorical variables and Mann-Whitney U tests for continuous variables. Catheter survival was assessed via Kaplan-Meier analysis with log-rank tests.

Results: 76 patients (38 per group) were included in this study. The 2.0 mL/hr group had a significantly higher weight than the 0.5 mL/hr group (median 6.35 vs. 4.63 kg, p = .005); other baseline characteristics were similar. The 0.5 mL/hr group had an equal number of 22G and 24G catheters (19 each), while the 2.0 mL/hr group had more 24G catheters (15 vs. 23). Median catheter longevity was comparable between groups (2.66 vs. 2.46 days, p = .888). Reasons for catheter removal did not differ significantly (Table 1). Functional measures—ease of flushing, blood withdrawal, and trace quality—were also similar (Table 1). Blood pressure measurement accuracy was not different (p = .743). Kaplan-Meier analysis showed no difference in time-to-failure between groups (median [95% CI] longevity until failure: 4.75 [3.11–6.39] vs. 4.50 [2.55–6.45] days; p = .450). Stratified analyses by catheter size also revealed no significant differences in time to failure (22G: p = .766; 24G: p = .492). See Figure 1 for catheter survival curves by group.

Conclusion: No significant differences were observed in catheter function or longevity between infusion rates. These findings support the use of lower infusion rates in infants requiring fluid restriction without compromising catheter performance.