///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

Epidural catheter functional assessment with high concentration local anesthetics

Abstract Number: T-30
Abstract Type: Original Research

Philip E Hess MD1 ; Justin K Stiles MD2

Background

Women who receive labor epidural analgesia (LEA) often require a supplemental bolus for pain control. In some cases the anesthesia provider may question if breakthrough pain is due to excessive labor pain or a failing catheter. This distinction can be diagnosed by injecting a volume (5 to 10ml) of a high concentration local anesthetics (HCLA) such as bupivacaine (Bupiv) or lidocaine (Lido). Lido might provide faster onset and a quicker determination, while Bupiv would allow for a longer effect if the epidural catheter is functioning. We investigated which high concentration of lidocaine or bupivacaine was superior for the assessment of a failed epidural catheter in women during LEA.

Methods

IRB approval was obtained for this observational cohort study. Consecutive charts of women who had a LEA were reviewed for the use of lidocaine (≥1%) or bupivacaine (≥0.25%). Cases where the HCLA was administered within 30 minutes of either placement or of delivery, when used for assisted delivery or cesarean, or specifically identified catheter issues, were eliminated. The time from HCLA administration to the next pain control intervention, and the number of subsequent interventions required for that patient were recorded. Chi-square and t-test were used for comparison. P<0.05 considered significant.

Results

3116 women received LEA over a 12 month period, of which 146 (4.7%) received HCLA. We eliminated 41 for use immediately prior to delivery (n=30) or within 30 min of initiation (n=3), assisted delivery (n=7) or catheter disconnection (n=1). Of the remaining 105, 56 received Lido and 49 Bupiv. There was no difference in demographic or obstetric characteristics between groups. There was no difference in the duration of epidural analgesia between groups. Women who received Bupiv were less likely to require a second intervention (24% vs. 51%; p=0.004), had a longer time to the next intervention (93 ± 40 minutes vs. 63 ± 42 minutes; p=0.04), and required fewer additional interventions after HCLA (0.4 ± 0.8 vs. 0.9 ± 1.1; p=0.01; (55% reduction, 95%CI: 14% to 97%)). There was no difference in complications between groups.

Discussion

Assessment of breakthrough pain during labor epidural analgesia must include an evaluation of whether the epidural catheter has failed. In some cases it can be difficult to determine if the epidural catheter is functioning correctly, high concentration local anesthetic are often used to make this assessment. Women who received Bupivacaine (≥0.25%) were less likely to need a second intervention, had a 48% longer time before the next intervention when necessary, and needed half as many subsequent interventions. The use of lidocaine (≥1%) results in more repeated requests for analgesia in the mother and a greater workload for the anesthesia provider.

SOAP 2016