Lander J, Brady-Fryer B, Metcalfe JB, Nazarali S, Muttitt S. Comparison of ring block, dorsal penile nerve block, and topical anesthesia for neonatal circumcision: A randomized controlled trial. JAMA 1997;278:2157-62.
Lori M. Newman, M.D. and Lili L. Church, M.D.
What anesthesia, if any, is most effective for neonatal circumcision?
Many clinicians contend that circumcision is not a painful procedure or that a rapid circumcision is less painful than the application of anesthesia. Individual studies have examined the efficacy and safety of topical eutectic mixture of local anesthetics (EMLA), ring block or dorsal penile nerve block. This study compared the effectiveness of these three types of anesthesia with placebo in neonatal circumcision.
Eligible subjects included healthy newborn males of diverse ethnic backgrounds, 1 to 3 days of age, born at 37 weeks gestational age or more. Neonates were excluded if they were unable to remain in the hospital for 6 hours after circumcision, had received other than routine neonatal medications, were breastfed by a mother taking sulfonamides or salicylates, or the parents declined informed consent.
Study design and validity
This was a randomized controlled trial comparing topical placebo, topical EMLA, dorsal penile nerve block, and ring block during circumcision. All infants had continuous heart rate monitoring and videotaping at baseline, during drug application, preparation, circumcision, and post-circumcision. Stages of circumcision included cleansing, separation of foreskin from the glans, application of the Gomco clamp with foreskin excision, and clamp removal. Study groups were similar for weight, age, Apgar scores and time of last feeding and were treated equally apart from the experimental intervention. All patients were accounted for at the end of the study. Physicians performing the circumcisions were not blinded to whether ring block or dorsal penile nerve block was used, although they were blinded to whether the topical cream group received placebo or EMLA. It is uncertain whether videotape review was by assistants unaware of group assignments.
Change in heart rate and proportion of time spent crying at each stage were used as indicators of neonatal discomfort. Methemoglobin levels were drawn 6 hours post-procedure.
Of the 54 infants initially enrolled, 2 dropped out; one due to inability to stay in the hospital 6 hours post-procedure, and one due to initiation of phototherapy. During drug administration, there was no significant difference in crying between the groups, but rise in heart rate was greatest for the ring block group. During circumcision, length of time crying was unequivocally greater in the placebo group. Heart rate was highest in the placebo group, followed by the EMLA group, dorsal block group and ring block group, respectively. Overall heart rate change was greater and crying lasted longer in the placebo group during circumcision as compared to the period of drug administration for the injection groups. Both heart rate and cry suggested that the ring block was more effective than dorsal penile nerve block during separation of foreskin, but not for application of the clamp with foreskin excision or clamp removal. Ring block averaged 48 seconds and dorsal block 25 seconds to perform. There were no differences among physicians in terms of length of procedure, neonatal heart rate or cry. Methemoglobin levels were elevated in the EMLA group but did not require treatment. Insignificant bruising was noted in half of the injection group. Two newborns in the placebo group developed choking, vomiting or apnea following circumcision, but this incidence was not found to be statistically significant.
Recommendations for clinical practice
Application of either injection or topical anesthesia clearly causes less neonatal distress during circumcision. Both ring block and dorsal penile nerve block are superior to topical EMLA. While the authors concluded that ring block was superior to dorsal nerve block, none of the P values nor adequate data are presented to allow readers to reconstruct similar conclusions. A recent trial comparing ring block to dorsal penile nerve block for post-circumcision pain control in older boys concluded that dorsal block is more effective (1). In summary, there are good data to support the use of either ring or dorsal block for neonatal circumcision. Physicians performing circumcisions should choose the method they are personally most comfortable performing.
1. Holder KJ, Peutrell JM, Weir PM. Regional anaesthesia for circumcision. Subcutaneous ring block of the penis and subpubic penile block compared. Eur J Anaesthesiol 1997;14:495-498.