///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

Randomized Controlled Trial of the Efficacy of Topical AmetopTM Gel in Reducing Pain of Local Anesthetic Infiltration prior to Elective Cesarean Delivery under Neuraxial Anesthesia

Abstract Number: S-55
Abstract Type: Original Research

Trevor Kavanagh MB BCh BAO FCAI1 ; Alison Dube BA2; Vit Gunka MD FRCPC3


Up to 22% of patients experience needle phobia.(1) The fear of needle injection pain may interfere with anesthetic care. Previous studies analyzing the benefit of skin topical anesthesia prior to neuraxial block (NB) have found mixed results.(2,3,4) The efficacy of AmetopTM (tetracaine 4% gel) in reducing pain prior to skin local anesthetic infiltration before NB in pregnant women has not been studied. AmetopTM has a significantly faster onset of more profound anesthesia compared to EMLA®.(5) We hypothesized that AmetopTM, compared to placebo, when applied for a minimum of 20 minutes would reduce the pain of local anesthetic infiltration in parturients undergoing elective cesarean delivery (CD) under NB.


CONSORT guidelines were followed. 78 parturients were randomized to either placebo or Ametop groups. Standardized protocol for 1% lidocaine infiltration was utilized. Primary outcome was the Numeric Pain Score (NPS) (0-10) at 30 seconds after local infiltration. Groups were compared using the Welch's t-test, an adaptation of the Student’s t-test, which corrects for the possibility of unequal variances between groups.


Six patients were excluded for protocol violation leaving 36 in each group. There was a statistically significant difference in the mean NPS between the placebo and Ametop groups: (3.51, SD = 2.22, 95%CI = 0.75) and (2.36, SD = 1.80, 95%CI = 0.61), respectively (P = 0.019). Mean application time of study cream: Placebo = 41.6, Ametop = 40 minutes.


Numeric pain score in Ametop group compared to placebo was 33% lower. While the clinical significance of this is uncertain, topical AmetopTM gel application before local anesthetic infiltration in elective CD prior to NB may be a useful adjunct in needle phobic parturients. There were no significant adverse events.


1. Wright S et al. Aust Fam Physician 2009.

2. Koscielniak-Nielsen Z et al. Anaesthesia 1998.

3. Ralston SJ et al. Anaesthesia 1993.

4. George RB et al. Can J Anaesth. 2008.

5. Lander JA et al. Cochrane Database Syst Rev. 2006.

SOAP 2014