///2009 Abstract Details
2009 Abstract Details2018-05-01T17:45:11+00:00

Ultrasound Increases the Labor Epidural Placement Success Rate in Resident Trainees

Abstract Number: 247
Abstract Type: Original Research

Manuel C. Vallejo MD, DMD1 ; Sukdhip Singh MD2; Amy L. Phelps PhD3; Venkat Mantha MD4; Patricia L. Dalby MD5; Jonathan H. Waters MD6


Epidural analgesia is the gold standard for pain relief during labor. The purpose of this study was to determine if ultrasound (US) measurement of the depth from skin to the epidural space prior to labor epidural catheter placement decreases the failed epidural placement rate in resident trainees. A secondary objective was to correlate ultrasound depth of the epidural space with actual depth of the needle at placement.


In this prospective, randomized, IRB approved trial, 370 parturients for elective labor epidural analgesia by a resident trainee with staff supervision were randomized into one of two groups: (Group 1) US determination of the distance from the skin to the epidural space before epidural catheter placement (US group), or (Group 2), standard labor epidural catheter placement without the use of US (Control group).

In the sitting position, patients in the US group were first scanned by an experienced US investigator to determine the distance from the skin to the epidural space utilizing both the longitudinal and transverse views at the L3-4 or L4-5 vertebral interspace utilizing the Sonosite Micromaxx ultrasound system (equipped with a 5-MHz curved array probe) before epidural catheter insertion. Using a saline loss to resistance technique, epidural catheters were inserted 5 cm into the epidural space, given a bolus of 0.1% ropivacaine (10cc) and fentanyl 100 mcg and placed on a standard continuous epidural infusion of ropivacaine 0.1% with fentanyl 2mcg/ml at 12cc/hr.

Outcome variables included incidence of failed epidural placement, number of epidural attempts, number of epidural site placements, and the incidences of post dural puncture headache, and epidural blood patches. Pearsons correlation coefficient was used to determine correlation between longitudinal and transverse views and clinical epidural needle depth. Results are reported as mean SD. A p < 0.05 is considered significant.


No differences were noted with respect to demographic data between groups (age, height, weight, gestation, gravidy, parity). The US group had fewer failed epidural catheters (P<0.04), fewer median epidural placement attempts (P<0.01), and fewer median site placements (P<0.01), compared to the Control group. Pearsons correlation coefficient comparing clinical depth to longitudinal US view and transverse US view was 0.91 and 0.91 respectfully. Pearsons correlation coefficient comparing the transverse US view to the longitudinal US view was 0.94. No differences were noted with respect to staff interventions, reboluses, reactivations, accidental dural punctures, delivery outcome, post dural puncture headaches, and number of epidural blood patches.


In resident trainees, US measurement of the epidural space before epidural catheter placement decreases the failed epidural placement rate, reduces epidural attempts, and requires less placement sites compared to epidural catheter placement without US.

SOAP 2009