Ultrasound Guided Central Line Insertion in Neonates: Pain Score Results From a Prospective Study

A single-center prospective randomized controlled study of neonates (preterm and term babies) who underwent an elective or emergent central line insertion between November 2016 and May 2017 was conducted at SGHUMC Neonatal Intensive Care Unit. Hospital's Institutional Review Board approved the study and an informed parental consent was signed for study entry. Inclusion criteria included neonates requiring TPN, antibiotic therapy for at least 7 days, and babies with poor or difficult venous access. Exclusion criteria included refusal to sign consent, patients with previously attempted or placed central lines, and patients who were converted from one technique to the other. Patients were randomized into the control and intervention group through a flip of coin each time a patient enrolled in the study The catheter used for all the patients was an epicutaneo-cava-catheter (ECC), silicone tube material kit, 24G, VYGON® (Aachen, Germany). All procedures were performed under sterile precautions such as hand washing, use of sterile gloves and gowns, facemask, hair cover, and protective eyewear.

The control group consisted of neonates who underwent a PICC line placement. The method of insertion performed followed the procedure previously described by Pettit. Patients in the intervention group underwent US-IJV. This procedure was carried out as follows: The patient's skin was sterilized with chlorhexidine gluconate and the area was infiltrated with local anesthetic agent (lidocaine). Vascular cannulation was performed using the ECC's winged needle. The target vessel was located via the US dynamic (real-time) method. At the point of needle insertion, the ECC was placed through the needle without guide wire placement. Once the catheter was inserted, a gentle aspiration was performed to show blood flow through the 3 ml syringe that was connected to the ECC. The catheter was then secured and fixed with simple steri-strips and covered by the transparent dressing. Both techniques were performed by two institutional neonatologists who according to their expertise, one performed all PICC line placements while the other performed all US-IJV.

Transducer selection and the axis of visualization are important to consider in the use of US for ECC, as such a linear 6-13 MHz transducer Sonosite M-turbo was used (manufacturer's recommendations). The transverse view shows the vessel under the transducer and the adjacent structures. The tip of the needle is visualized and inserted at a 45° angle. The longitudinal view helps to track the needle progression toward the IJV. Post procedural chest radiography was done for both groups to confirm placement and evaluate for complications.

The primary outcome measured was the pain score difference between Ultrasound inserted central line and peripherally inserted central line. The pain score was measures using the Neonatal Pain, Agitation and Sedation Scale (N -PASS). The N-PASS is based on several criteria: crying / irritability, behavior / state, facial expression, extremities / tone and vital signs. Patient characteristics such as gestational age, age, gender, admission diagnosis, weight have been taken into account and the scores was recorded by the nurse in charge of the baby before and during the procedure. Pain score difference was calculated by subtracting the score during the procedure from the pain score before the procedure.

The secondary outcome measures included the number of first successful attempts, number of total attempts and procedure duration. Additional patient information collected included gender, TPN administration, gestational age, birth weight and diagnosis.