///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

GPS for Neuraxial Block - A RCT Evaluation of Neuraxial Block Placement Between Using Palpation of Landmarks Versus Pocket-Size Handheld 3-D Guided Ultrasound (US) Navigation Device in Obese Parturients

Abstract Number: T2C-337
Abstract Type: Original Research

Jennifer Fichter MD1 ; Vernon Ross MD2; Lynne Harris BSN3; Peter Pan MD4

Background: Palpation(P) of the spinous process and surface landmarks is the traditional method for neuraxial block(NB) placement. However, P becomes challenging in obese parturients. Ekinci et al and Wang et al showed conventional ultrasound(CUS) decreased NB attempts especially when P was difficult.1,2 CUS is limited by its bulkiness, less optimal image around the spine, long learning curve and subjective user interpretation. A new pocket size US (Accuro,Rivanna Inc) addresses some of these limitations by providing real time navigating guidance using pattern recognition algorithm for spinal bony structures with simulated 3D image overlay to identify the midline intervertebral space. We hypothesized that such US (Accuro) may reduce time and attempts to obtain LOR during CSE in obese patients.

Methods: After Novant Health & Wake Forest IRB approval, 60 parturients, with BMI>30 and requesting NB analgesia, were planned for informed consent and randomization to groups(Gp) P and US(U). Gp P utilized usual landmark P to identify Tuohy needle insertion site (NIS). In Gp U, NIS was identified and marked by Accuro US, and a second provider, without P of landmarks, performed the CSE. Experienced providers performed the CSE in both groups. The primary outcome was the time from Tuohy needle insertion to epidural loss of resistance (LOR). Secondary outcomes included: # of Tuohy needle passes and redirections, 1st attempt success, US scanning or P time and patient’s reported VAS pain and satisfaction scores (0-10) on the CSE. 30/group was required to show a 20% group difference in time to LOR with power=0.80, α=0.05 and P<0.05 as significant.

Results: 49(23-Gp P, 26-Gp U) of 60 planned evaluable subjects were enrolled so far. Demographics were similar between groups. Median US scanning time was 31s in Gp U vs 25s for P in Gp P. Median time to LOR was shorter (94s) in Gp U than the 108s in Gp P. 50% of Gp U and 30% of Gp P accomplished LOR with 1st pass without redirection. Mean and median number of needle passes and redirections and patients’ reported pain VAS with CSE were lower in Gp U (Table 1). Statistics will be performed after all 60 subjects enrolled and presented at SOAP.

Conclusions: Preliminary data suggest use of Accuro US may shorten time for successful LOR, increase success rate of 1st pass without redirection and lessen pain vs traditional P method in CSE for obese parturients.

1.Ekinci M, et al. JCA 2017;37:82-5

2.Wang Q, et al. CMJ 2012;125:3840-3



SOAP 2019