Point-of-care ultrasound for neonatal central catheter positioning: impact on X-rays and line tip position accuracy

Abstract

Objective of the study was to compare number of X-rays performed for neonatal central line tip positioning when real-time US is used compared to X-ray only, and to assess consequences on position accuracy, irradiation and cost. Retrospective monocentric cohort study conducted at Evelina London Children's Hospital Neonatal Unit over 6 months. Study was conducted during implementation of US for line tip localisation with formulation of US protocol. Tip position on X-ray was reviewed by one neonatologist and one radiologist and inter-rater agreement calculated. Criteria for good, satisfactory or inadequate position of the tip were defined. Estimated effective radiation dose and cost for each X-ray was determined. Two hundred seventy-four lines were inserted (nPICC, UVC, UAC). Eighty-three lines were scanned with US (US group); 191 lines were not (no-US group). Number of X-rays performed was significantly lower in the US group: 1.19 vs. 1.5 (p 0.001), related to a significantly lower percentage of lines requiring multiple X-rays (38.7% no-US group vs. 19.9% US group; p 0.004). Accuracy was higher in US group with more lines at cavoatrial junction (p 0.05) and was significantly increased with US use for lines inserted from lower limbs (22.9% and 76.2%, p 0.001). Inter-rater agreement was strong (k > 0.8). US group received lower mean radiation dose (p < 0.001) and cost related to X-ray was significantly reduced (p 0.001).

Conclusion: Real-time US use for line tip positioning in the NICU significantly decreased the number of X-rays performed and was associated with better-positioned lines, decreased irradiation and cost.

What is known: • The use of point-of-care ultrasound (PoCUS) by critical care providers in neonatology has increased in recent years. International guidelines advocate for the use of PoCUS as valid guidance to practical procedures in neonatology. • Central catheters (umbilical catheters and neonatal peripherally inserted central catheters) are among the most commonly used devices to support NICU patients. Proper positioning is crucial to avoid complications and PoCUS has high sensitivity and specificity in accurately determining line tip position. The current standard practice for line tip position confirmation in neonatology is still conventional radiography despite multiple evidence suggest significant inaccuracy of X-ray compared to ultrasound.

What is new: • PoCUS implementation for line tip positioning leads to a significant decrease in the number of X-rays performed, in radiation effective dose and costs. PoCUS evaluation of central catheters significantly increases the accuracy of the final line tip position with more lines at the cavoatrial junction. • Training is fundamental for univocal interpretation of ultrasound images and an effective learning strategy is being proposed.

Keywords: Central catheters; Neonatology; Point-of-care ultrasound; Vascular access.