Ultrasound (US)-guided peripheral IVs have a high failure rate. We explore the relationship between the quantity of catheter residing within the vein and the functionality of the catheter over time.Methods
This was a prospective, observational single-site study. Adult ED patients with US-guided IVs had the catheter visualised under ultrasound post-placement. IV placement time and catheter length residing in the vein was obtained. Exclusions included catheter not visualised, patient discharged from ED unless IV failed, <24 hour hospitalisation unless IV failed or patient self-removed IV.Methods
Inpatient follow-up occurred within 24, 48 and 72 hours from the IV placement time. Catheter functionality was noted. If the catheter failed, the time and reason for failure was documented.Results
113 patients were enrolled; 27 were excluded. Of the 86 study subjects, 29 (33.7%) patients’ IVs failed and 57 (66.3%) remained functional. Median time to IV failure was 15.6 hours. 100% of IVs failed when <30% of the catheter was in the vein; 32.4% of IVs failed when 30%–64% of the catheter was in the vein; no IVs failed when ≥65% of the catheter was in the vein (p<0.0002). The HR was 0.71 (95% CI 0.60 to 0.83), and for every 5% increase of catheter in vein, the hazard of the IV failing decreases by 29% (p<0.0001).Conclusion
The quantity of catheter residing in the vein is a key predictor of long-term functionality of US-guided IVs and is strongly associated with the hazard of failure within 72 hours. Catheter failure is high when <30% of the catheter resided in the vein. Optimum catheter survival occurs when ≥65% of the catheter is placed in the vein.