Combination Analgesia for Neonatal Circumcision

Procedure/Interventions/Drugs Several forms of analgesia, including local anesthetic creams or local anesthetics administered by injection, will be compared as methods of pain control during circumcision. All of these analgesics have already been used for intra-operative pain control during circumcision. The drugs that will be used in the study are all local anesthetics of the amino-amide group, and include lidocaine and prilocaine. Because there is no consensus on the best anesthetic for circumcision, the investigators propose a comparative study. Children taking part in this research will be put into groups which are selected by chance. There will be three different groups. One of the groups will serve as a control group, and in the three other groups combinations of anesthetics will be tested. The control group will be receiving the usual anesthetic used in the normal nursery for pain control during circumcision, while the combination groups will be receiving additional anesthetic agents. Randomization to groups will be done using a random sequence generator. The intervention for each patient will then be placed in a sealed envelope, and will be opened by the individual performing the circumcision at the time the procedure is scheduled.

The following interventions will be used:

EMLA Topical Product:

EMLA cream is a eutectic mixture of 2.5% lidocaine and 2.5% prilocaine, used as a topical anaesthetic to diminish pain from cutaneous procedures. Seventy minutes prior to circumcision, the newborn will be placed in the circumcision mold with the legs restrained, and attached to a monitor. 1 gram of EMLA cream will be applied by the nurse to the penis using a syringe and then wrapped with a dressing (Tegaderm). After sixty minutes they will be returned to the circumstrep, reattached to the monitor, and legs will be restrained. The Tegaderm and drug will be removed, and the infant will be left to settle then the circumcision will take place.

Dorsal Penile Nerve Block (DPNB):

Dorsal penile nerve block is an anesthetic technique first described in 1978, and has since then been extensively evaluated in the management of pain during circumcision. DPNB will be done with 1% lidocaine without epinephrine injected at two sites at the base of the penis (2 and 10 o'clock). Ten minutes prior to circumcision, the newborn will be placed in the circumcision mold with legs restrained, and attached to a monitor. A total of 2 mg/kg of 1% lidocaine without epinephrine will be used to perform the block, and equal aliquots in milliliters will be injected at the two sites at the base of the penis. The block will be done by the circumciser. Five minutes after the block the circumcision will be performed.

Ring Block:

Ring block is another anesthetic technique described in the 1990s that has also been examined for pain control during circumcision. Ring block will be done with 1% lidocaine without epinephrine injected in a band around the penis halfway along the shaft. Ten minutes prior to circumcision, the newborn will be placed in the circumcision mold with the legs restrained, and attached to a monitor. A total of 2 mg/kg of 1% lidocaine without epinephrine will be used to perform the ring block and will be injected in a band around the penis. The block will be done by the circumcising physician. Five minutes later the circumcision will be performed.

Intervention groups:

Control group: (1) EMLA Combination Groups: (2) EMLA + Sucrose (3) EMLA + Ring Block + Sucrose; (4) EMLA + Sucrose + DPNB For all groups the same procedures detailed above for EMLA, DPNB, and ring block will be followed depending on patient grouping.

General:

EMLA will be used on all patients.

Videotaping:

In order to ensure that the study is properly blinded, video-taping of the procedure will need to take place. A video camera will be set to capture the infant's face and torso and the monitor, but not the individual performing the circumcision. The videos will be labeled numerically, and not by patient name. Videos will be viewed by two other individuals (not present at the circumcision itself and not responsible for obtaining consent), and a possible third viewer may be required to resolve conflicting opinions. The video tapes will not be seen by any other individual, and will only be for data collection and pain scoring. They will be kept in the possession of the two principal investigators in a locked drawer in their offices at all times. The video tapes will be destroyed after the completion of the study.

Outcomes:

The primary outcome variable will be the pain score. Pain scores consist of behavioral components of the infant such as facial expression, crying, breathing patterns, arm movement, and leg movement. Secondary outcomes will include effects on heart rate, crying time, and oxygen saturation (obtained from the monitor).

Patients' participation can be ended at any time by the investigator. Significant new findings will be conveyed to the parents of the newborn.

Risks

The main risks of participation in the study are:

1. the adverse effects that might result from circumcision itself, such as pain, bleeding, surgical trauma, local infections, and meatal stenosis.

2. adverse effects that may result from drugs, such as allergic reactions

3. adverse effects that might result from specific drug administration technique, EMLA may result in methemoglobinemia and local skin reactions such as blanching, edema, and erythema. DPNB and ring block may result in bruising, bleeding, and hematomas at the injection site.

4. adverse effects if the anesthetic is erroneously injected systemically.

Although the investigators have taken steps to minimize the risks of this study, there may also be unforeseeable risks.The parents may choose to withdraw consent at any time during the study.

Benefits All the anesthetics that will be used in the study have already been shown to play a role in pain reduction during circumcision, however some seem to be more effective than others. The participating child will directly benefit from the study, since his pain will be controlled to some extent during the circumcision procedure. Furthermore, if the study provides conclusive evidence about the most effective method of analgesia, then guidelines can be instituted so that in the future all newborns will have their pain successfully controlled during the procedure.