Objective: To evaluate epicutaneous application of 5% lidocaine-prilocaine
and 30% lidocaine cream anesthetics for neonatal circumcision.
Methods: The efficacy of 5% lidocaine-prilocaine and 30% lidocaine creams w
as compared in a randomized, double-blind, placebo-controlled trial. sixty-
one neonates were randomly assigned to one of three groups: 5% prilocaine-l
idocaine (n = 20), 30% lidocaine (n = 20), and a control group that receive
d an acid-mantle cream (n = 21). Heart rate, oxygen saturation, and crying
time were monitored before, during, and after circumcision. Blood pressure
was measured before and after circumcision.
Results: Mean peak heart rates for the 5% lidocaine-prilocaine, 30% lidocai
ne, and control groups (+/- standard deviation) were 146 +/- 16, 157 +/- 10
, and 164 +/- 16 beats per minute, respectively. During four of six active
phases of circumcision, the 5% lidocaine-prilocaine group suppressed signif
icant increases in heart rate better than 30% lidocaine, which was more eff
ective than control (dorsal clamp, P < .001; bell clamp on, P = .001; tight
ening, P = .001; bell clamp off, P < .001). During tightening of the bell c
lamp, significantly less crying was seen in the 5% lidocaine-prilocaine gro
up (13 +/- 12 seconds) compared with 30% lidocaine (24 +/- 14 seconds) and
controls (38 +/- 27 seconds) (P < .001). The group that received 5% lidocai
ne-prilocaine also had no significant increase in systolic (t = 1.6, P = .1
2) or diastolic (t = 1.9, P = .067, respectively) blood pressure, unlike th
e group receiving 30% lidocaine (t = 4.8, P = .001 and t = 2.9, P = .009, r
espectively) and the placebo group (t = 2.5, P = .023 and t = 2.3, P = .032
). There were no significant differences in oxygen saturation (alpha = .05,
power 0.79).
Conclusion: Epicutaneous 5% lidocaine-prilocaine was more effective than 30
% lidocaine for neonatal circumcision, better reducing neonatal stress indi
cators. Lidocaine-prilocaine significantly shortened frying time during one
of the most painful phases of circumcision. Both topical anesthetics were
more effective than placebo in attenuating the behavioral and physiologic i
ndicators of neonatal pain. (C) 1999 by College of Obstetricians and Gyneco
logists.