1078 Arnett, Jones, and Horger

170

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September 1990 Am J Obstet Gynecol

Iilll LIDOCAINE

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Fig. 4. Comparisons of pulse rate between control group versus lidocaine group.

dure, but surely we are building a large enough body of data to encourage its use and training throughout this country.

REFERENCES 1. Slaby AR, Drizo T. Circumcision in the United States. Am

] Public Health 1985;75:878-80. 2. Warner E, Elliot S. Benefits and risks of circumcision. Can

Med AsocJ. 1981;125:967-92. 3. Stang H], Gunnar MR, Snellman L, Condon LM, Kesten­

baum R. Local anesthesia for neonatal circumcision­effects on distress and cortisol response. ]AMA 1988; 259: 1507-11.

4. Maxwell LG, Vaster M, Wetzel RC, Niebyl]R. Penile nerve block for infant circumcision. Obstet Gynecol 1987;70: 415-9.

5. Kirya C, Werthmann MW. Neonatal circumcision and pe­nile dorsal nerve block-a painless procedure. ] Pediatr 1978;92:998-1000.

6. Anand K]S, Hickey PRo Pain and its effects in the human neonate and fetus. N Engl] Med 1987;317:1321-9.

7. Schiff DW, Pediatr Committee. AAP member alert­circumcision. [Letter to Members]. American Academy of Pediatrics, March 10, 1989.

8. Rawlings D], Miller PA, Engel RR. The effect of circum­cision on transcutaneous P02 in term infants. Am ] Dis Child 1980; 134:676-8.

Editors' note: This manuscript was revised after these discussions were presented.

Discussion

DR. GENE BURKE'IT, Miami, Florida. Dr. Arnett and his colleagues have brought yet another study that en­dorses the efficacy of dorsal penile nerve block for cir­cumcisions. Many other studies'" in which dorsal penile nerve block was used for circumcision in newborns have

shown reduction in pain, crying, agitation, and physi­ologic stress during the procedure. Prolonged agitation and reluctance to feed were minimal occurrences in dorsal penile nerve block circumcised newborns un­dergoing dorsal penile nerve block. On the other hand, if anesthesia was not used, heart rate rose by 34%, blood pressure by 15%, oxygen saturation decreased by 16%, and cortisol levels also were expectedly higher. With dorsal penile nerve block these side effects were mark­edly reduced statistically.

Despite this favorable situation, one survey' reported that only 23 % of physicians used the technique of dorsal penile nerve block. Physicians who do not use the pro­cedure are primarily under the guise: (1) that newborns do not feel intense pain during circumcision because of incomplete myelination of nerve pathways; (2) that immediate side effects are extremely shortlived, pro­duce no long-lasting or residual deficits, and can be cushioned by tender loving care, (3) that dorsal penile nerve block itself adds pain and stress from the injec­tion, together with the risks inherent in another step in the procedure.

Dr. Arnett and his colleagues are to be congratulated on this timely reminder that presents convincing data on the efficacy of dorsal penile nerve block in relieving intraoperative and postoperative irritability, pain, and tachycardia and in decreasing oxygen saturation. They report that when independent blinded observers (phy­sicians and nurses) used grading scales of infant irri­tability, neonates with dorsal penile nerve block had significantly lower scores (less irritability) than the con­trol group. Unfortunately the rating scale for irritability was omitted from the manuscript; had it been included,

Volume 163 Number 3

10D

Effectiveness of penile nerve block in circumcision 1079

\TIl lID()~AINE

Fig. 5. Comparisons of oxygen saturation between control group versus lidocaine group.

it would have facilitated a more direct evaluation to the conclusions of the study.

Intraoperatively, oxygen saturation showed a greater decrease in the infants without block. A return to a normal level occurs by 5 minutes after operation. The authors did not explore the significance of this finding. At what time does the nadir occur and how long does it last? Are there any harmful effects produced by this change in oxygen saturation?

Perhaps, too, Dr. Arnett should have included data on irritability, pulse, and oxygen saturation immediately after injection and before circumcision. Since these au­thors recorded scores at I-minute intervals, these data are available and their inclusion in the report would define the effect of the injection itself, a problem raised by nonusers of dorsal penile nerve block.

Another area of concern is the study groups. Initially, Dr. Arnett and colleagues started with two groups­one received lidocaine and the other saline solution injections. When concern "over whether control saline could produce anesthesia" arose, the investigators sub­divided the saline control group and reported on seven neonates in whom no injection was used. This changed the study design, as well as the control group, and weak­ened the statistical power' of the conclusions. From this perspective no valid conc"Iusions can be made, especially on the noninjected neonates. A larger number of non­injected neonates should be studied separately as a third group in the original concept.

The differences between the lidocaine group and the remaining saline solution group, 23 in total, are, however, sufficient enough to indicate trends strong enough to support the efficacy of the dorsal penile nerve block.

Even using 0.2 ml of lidocaine at each site, half of

the dose recommended in other studies, Dr. Arnett and associates have shown us a simple, easy, effective method of controlling pain and irritability without in­creasing the overall complication rate of circumcisions, reportedly 0.2% to 0.6%. Perhaps the real question to be put is not whether we should be routinely using dorsal penile nerve block but rather whether proper genital hygiene would effectively reduce urinary infec­tions in the uncircumcised infant. The American Acad­emy of Pediatrics6 in its concern for an increased in­cidence of urinary tract infections among uncircum­cised infants, emphasized that mothers of newborns should be advised of this recent finding as an important part of the decision-making process for circumcision. Notwithstanding this new position, the message from Dr. Arnett and colleagues is that the procedure can be performed safely and humanely. The crying, agitated newborn is indeed in pain, with dorsal penile nerve block, there is no longer an excuse not to relieve that agony. We thank them for that rejoinder.

REFERENCES 1. Maxwell LG, Vaster M, Wetzel RC, Niebyl JR. Penile nerve

block for newborn circumcisions. Obstet Gynecol 1987; 70:415-9.

2. Williamson PS, Neonatal cortisol response to circumcision with anesthesia: Clin Pediatr 1986;25:412-5.

3. Stang HJ, Gunnar MR, Snellman L, Condon LM, Kesten­baum R. Local anesthesia for neonatal circumcision: effects on distress and cortisol response.JAMA 1988;259:1507-1.

4. Ferguson KJ, Caplan RM, Williamson PS. Factors associ­ated with behavior change in family physicians after CME presentation: J Med Educ 1984;59:662-6.

5. Cotton T. The "power" of sound statistics. JAMA 1990; 263:281.

6. Schiff DW. Pediatric Committee. AAP member alert­circumcision [Letter to Members]. American Academy of Pediatrics, March 10, 1989.

1080 Arnett, Jones, and Horger

DR. DAVID SOPER, Richmond, Virginia. Did you con­sider using infants who were not circumcised at all as a control group? Second, subjective scales by their na­ture cannot really be considered continuous data. Prob­ably a more appropriate statistical test would be the Mann-Whitney V test.

DR. FRANK GREISS, Mooresville, North Carolina. Dr. Arnett, I think Dr. Burkett asked this question, but I will ask it again. Did you actually look at the parameters before and while you were doing the nerve block itself? Would you describe for me who trained your resi­dents to do circumcisions at the Medical University of South Carolina, and what sort of a formal process do you go through to do this?

DR.JOHNW. C.JOHNSON, Gainesville, Florida. I want to congratulate you, Dr. Arnett, on a nice study. It was one that needed to be done. I was very curious about the drop in oxygen saturation. Do you have an expla­nation for that?

DR. ARNETT (Closing). The grading scale is some­thing that was added on. I was actually just going to measure pulse rate and oxygen saturation, and then I thought a scale would not be a bad thing to look at. We really did not put as much attention into our scale as we should have, and I am not sure what that data really mean. They definitely show that people could tell a difference even with a very widely subjective scale.

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September 1990 Am J Obstet Gynecol

We did have some data right after the injections took place. Looking at what happened to oxygen saturation and crying, on average, they resolved in 30 seconds after the injection. Obviously some infants cried more than others, but on an average the pulse returned to normal and the oxygen saturation returned to normal very quickly. We did determine these on the first 35 patients that we had in the study, but I did not present those data.

Regarding Dr. Greiss' question on how we were trained, our residents in the first-year level are gen­erally taught by the senior residents. Our first-year res­idents go in with the senior residents and learn to do circumcisions under their guidance. When we feel they are performing them on a level that we can leave them alone, we do. This generally is in the first few months. We are not teaching the block to residents as a manner of routine, but I encourage them to use it and teach my technique when requested.

Finally, regarding the drop in oxygen saturation, there have been several studies by anesthesiologists showing any infant under stress can undergo a drop in oxygen saturation. I am sure that this is what is happening when the baby cries or is under a certain amount of stress; the oxygen saturation typically drops a certain degree.

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