CHAPTER 179 Subcutaneous Ring and Dorsal Penile Block for Newborn Circumcision
The American Academy of Pediatrics has recommended routine use of analgesia for circumcision since 1999. A recent survey of residency program directors found that 97% of pediatric, family medicine, and obstetrics and gynecology programs that teach circumcision teach the administration of an anesthetic, either locally or topically. Therefore, the controversy about whether or not infants should receive analgesia or anesthesia for circumcision has ended. Previously, the controversy weighed whether the incompletely developed neonatal nervous system was capable of experiencing pain against the risk of anesthesia. Many clinicians chose not to use circumcision anesthesia, in part because of this controversy, but also owing to their lack of training or experience in the techniques available, the additional steps (and time) required to perform the procedure, and the time required for the anesthesia to take effect. However, with proper planning, the number of steps and the time required are minimal. In addition, studies have documented the safety of anesthesia as well as the improved outcomes in neonates.
Common analgesic and anesthetic techniques for circumcision include subcutaneous ring block, dorsal penile nerve block (DPNB), topical anesthesia (see Chapter 10, Topical Anesthesia), and precircumcision oral analgesics. Several studies have reported that the subcutaneous ring block is the most effective, and it has therefore basically replaced DPNB as the anesthetic technique of choice. (This is different in adults, where the most effective anesthesia for office circumcision is probably a combination of all three.) This chapter discusses subcutaneous ring block, DPNB, and an alternative technique of DPNB using a single injection. All three techniques appear to be more effective than topical or oral anesthesia, and no major complications have been reported with any of these methods. Studies have found that anesthetized infants show less crying, tachycardia, and irritability and exhibit fewer behavior changes for the 24 hours after circumcision. They also have less variability in oxygen saturation and blood pressure during the procedure and lower serum cortisol levels after the procedure. One small study in children found that lidocaine–prilocaine (eutectic mixture of local anesthetics, or EMLA) cream applied an hour before the ring block reduced the pain of needle puncture. However, because most clinicians are not able to prepare a newborn an hour before its circumcision, they would probably rely on the nursing staff to apply the cream. Conversely, in adults and children who are about to undergo office circumcision under local anesthesia, waiting an hour for the lidocaine–prilocaine cream to take effect may be very worthwhile.
NOTE: There is a risk of methemoglobinemia after use of EMLA cream in certain situations. However, this risk is minimized with circumcision because it is used only once on intact skin and not with other drugs known to cause methemoglobinemia (e.g., nitric oxide).
Before the procedure, note the anatomy as shown in Figure 179-1. Consider giving the infant a few swallows of glucose water or a sugar-coated pacifier to minimize distress. In a warm room, have an assistant hold the infant or place the infant’s legs in restraints. Fold back the diaper to expose the penis.
NOTE: As the clinician becomes more comfortable performing ring block or DPNB, time may be saved by performing the procedure before the infant is surgically prepared. This allows time for the anesthetic to take effect while other preparations are being made.