Dynamic Needle Tip Positioning
Dynamic needle tip positioning (DNTP) with ultrasound guidance is a technique that significantly enhances the accuracy and safety of vascular access procedures in pediatric patients. This method utilizes real-time ultrasound imaging to guide the placement of a needle or catheter into a blood vessel, allowing one to visualize the needle tip's location relative to the vessel and surrounding structures. This precise guidance reduces the risk of complications, such as arterial puncture or hematoma formation.
In addition to enhancing safety, DNTP reduces the number of needle passes needed to access the vessel, which is particularly beneficial for small or fragile pediatric patients. This technique also decreases patient discomfort during the procedure.
In 2012, Clemmeson et al. explored the effectiveness of DNTP in teaching ultrasound novices to cannulate peripheral vessels. Participants received a brief lecture and live demonstrations before attempting vascular access on a gelatin phantom using both DNTP with the short-axis out-of-plane (SA-OOP) approach and the long-axis in-plane (LA-IP) approach. The study found that DNTP SA-OOP had a significantly higher success rate (97%) compared to LA-IP (81%). Additionally, the needle tip was more centrally located within the vessel when using DNTP SA-OOP.
Takeshita et al. extended this research to pediatric patients with radial arteries of 4mm depth or greater, a challenging scenario for ultrasound-guided access. Their study showed that DNTP SA-OOP led to higher first-pass success rates (85% vs. 50%) and total success rates (95% vs. 60%) compared to standard SA-OOP, with DNTP also being faster.
Lui et al. further demonstrated that in neonates, DNTP achieved a first-pass success rate of 40% and an overall success rate of 96.7%, significantly reduced procedure time (1.5 vs. 4.7 minutes), and an eightfold reduction in hematoma incidence compared to the palpation technique.
Ye et al. evaluated DNTP in neonates performed by anesthesiology trainees, incorporating a modification described by Nakayama et al., where subcutaneous saline was injected to increase the depth of the radial artery and create an anechoic fluid collection, enhancing needle maneuverability and visualization. This modified DNTP was nearly three times faster, had a higher success rate, and reduced hematomas by 64% compared to the standard DNTP technique.
These studies collectively highlight DNTP's potential to improve success rates, speed, and safety in ultrasound-guided vascular access, making it a valuable technique for both novice and experienced practitioners, especially in pediatric care. The evidence supports the broader adoption of DNTP in clinical practice to achieve better patient outcomes. Dynamic needle tip positioning (DNTP) with ultrasound guidance is a technique used to improve the accuracy and safety of vascular access procedures in pediatric patients. It involves using real-time ultrasound imaging to guide the placement of a needle or catheter into a blood vessel.
Dynamic Needle Tip Positioning Technique
Hold the ultrasound probe in your non-dominant hand. Place the probe on the skin and adjust until the target vessel is visualized in the short axis (cross-sectional view) on the ultrasound screen.
Final Placement and Procedure:
After the needle is properly positioned within the vessel, proceed with the necessary procedure, such as advancing the catheter, drawing blood, or administering medication. Monitor the ultrasound screen to confirm the catheter’s proper placement if needed.
Clemmesen, L., Knudsen, L., Sloth, E. and Bendtsen, T., 2012. Dynamic needle tip positioning–ultrasound guidance for peripheral vascular access. A randomized, controlled and blinded study in phantoms performed by ultrasound novices. Ultraschall in der Medizin-European Journal of Ultrasound, 33(07), pp.E321-E325.
Takeshita J, Yoshida T, Nakajima Y, Nakayama Y, Nishiyama K, Ito Y, Shimizu Y, Takeuchi M, Shime N. Dynamic Needle Tip Positioning for Ultrasound-Guided Arterial Catheterization in Infants and Small Children With Deep Arteries: A Randomized Controlled Trial. J Cardiothorac Vasc Anesth. 2019 Jul;33(7):1919-1925. doi: 10.1053/j.jvca.2018.12.002. Epub 2018 Dec 4. PMID: 30638922.
Liu L, Tan Y, Li S, Tian J. "Modified Dynamic Needle Tip Positioning" Short-Axis, Out-of-Plane, Ultrasound-Guided Radial Artery Cannulation in Neonates: A Randomized Controlled Trial. Anesth Analg. 2019 Jul;129(1):178-183. doi: 10.1213/ANE.0000000000003445. PMID: 29787409.
Ye P, Tan Y, Ye M, Li S, Bai L, Liu L. A novel method for ultrasound-guided radial artery cannulation in neonates by trainee anaesthesiologists: A randomised controlled trial. Eur J Anaesthesiol. 2020 Feb;37(2):91-97. doi: 10.1097/EJA.0000000000001089. PMID: 31567592.
Nakayama Y, Nakajima Y, Sessler DI, Ishii S, Shibasaki M, Ogawa S, Takeshita J, Shime N, Mizobe T. A novel method for ultrasound-guided radial arterial catheterization in pediatric patients. Anesth Analg. 2014 May;118(5):1019-26. doi: 10.1213/ANE.0000000000000164. PMID: 24781571.