A randomized, placebo-controlled comparison of EMLA() and dorsal penile nerve block for pain relief during neonatal circumcision

Prim Care Update Ob Gyns. 1998 Jul 1;5(4):196. doi: 10.1016/s1068-607x(98)00128-0.

Abstract

Objective: To evaluate the relative efficacies of eutetic mixture of local anesthetics (EMLA()) cream and dorsal penile nerve block (DPNB) for pain relief during neonatal circumcision.Methods: After parental informed consent, appropriate-for-gestational age, term, healthy newborns were randomized to receive either EMLA cream and placebo saline DPNB or placebo cream and 1% lidocaine DPNB. Placebo and EMLA cream were prepared by the pharmacy and applied by study nurses. Preloaded syringes of saline or 1% lidocaine were also prepared by the pharmacy for the DPNB injections. This ensured blinding of the surgeons and assistants at the time of circumcisions. Circumcisions were performed with the Gomco clamp technique by one of three obstetrics and gynecology residents. Pain levels were assessed by measuring pulse and respiratory rates and determining Brazelton states at each step of the circumcision. Videotapes were made of each procedure to allow later scoring by a single blinded observer for Brazelton states. Brazelton state scores increase with increased infant pain and distress, as do heart and respiratory rates. Means were compared by t test and proportions by chi(2). A P value of.05 was considered statistically significant.Results: A total of 60 infants were randomized, 29 to DPNB and 31 to EMLA. Preoperative Brazelton state scores, heart rates, and respiratory rates were similar in both groups. Brazelton state scores were lower in the DPNB group at each step of the procedure-injection, dissection of the foreskin, clamp placement, and clamp removal-and postoperatively and overall, but the differences only reached statistical significance during dissection and clamp removal. Heart and respiratory rates also were lower at all surgical steps in the DPNB group but only reached statistical significance during postoperative observation.Conclusions: Although both EMLA and DPNB have been shown in other studies to decrease pain during neonatal circumcisions, DPNB has greater effectiveness in relieving the pain of circumcision.