Plain and buffered lidocaine for neonatal circumcision.

Abstract

To determine if buffered lidocaine provided a more effective nerve block in a short time than plain lidocaine for neonatal circumcision. One hundred ninety-four newborn males were studied in a randomized trial using two dorsal penile nerve block preparations for circumcision. Ninety-two received plain lidocaine, and 102 received buffered lidocaine. The infants were evaluated at timed intervals before the procedure, during anesthetic injection, and during circumcision. Objective measurements of heart rate and oxygen saturation, and subjective determinations of behavioral state were recorded. Using heart rate as the major outcome variable, it was determined that 65 subjects per group would be needed to achieve a power of .08. Complications also were noted. Heart rates and oxygen saturations were similar in the two groups at each timed interval. The behavioral characteristics and amount of crying also were comparable in both groups. The only complication was minor bleeding, seen in each group. Adding a buffering agent to lidocaine did not provide a more effective level of anesthesia in a short time.