Pediatrics, Volume 100, Issue 2, Page e3. August 1997.
* Department of Pediatrics and Adolescent Medicine, Group Health, Inc;
† University of Minnesota Institute of Child Development, Minneapolis, Minnesota
Pediatrics, Volume 100, Issue 2, Page e3. August 1997.
* Department of Pediatrics and Adolescent Medicine, Group Health, Inc;
† University of Minnesota Institute of Child Development, Minneapolis, Minnesota
Objective. To explore techniques that can be utilized in addition to the dorsal penile nerve block (DPNB) to further reducethe neonate's stress and pain from routine circumcision, and thusmake the procedure more humane.
Setting. Level 1 nursery at a community hospital.
Subjects. Eighty healthy, term, newborn male infants scheduled for routine neonatal circumcision.
Study Design. Prospective and randomized; double blind and placebo controlled for the study solutions.
Methods. Four statistically similar groups of 20 were studied. The control group included infants circumcised using: a) arigid plastic restraint board; b) standard DPNB; and c) a pacifierdipped in water to comfort the infant. Each study group differedfrom the controls in one variable including: 1) using a speciallydesigned, physiologic circumcision restraint chair; 2) pH bufferingof lidocaine hydrochloride used for DPNB; and 3) offering a pacifierdipped in a 24% sucrose solution during the DPNB and circumcision.Behavioral observations were recorded and compared for each groupstarting before the injection of lidocaine hydrochloride and continuingthrough the completion of the circumcision. Plasma for cortisollevels were collected 30 minutes after the circumcision.
Results. Neonates circumcised on the new restraint chair showed a significant decrease in distress scores (>50%) comparedwith the control group on the rigid molded-plastic restraint.The pacifier dipped in sucrose had a distress-reducing effectduring both the post-DPNB injection and circumcision periods.The infants who were injected with the buffered lidocaine showedno differences in distress from the controls. The plasma cortisollevels were not significantly affected by any additional techniqueand were comparable to the levels previously reported.
Conclusions. When neonatal circumcisions are performed routinely, they should be done as humanely as possible. This studydemonstrates that, when used in conjunction with DPNB, a pacifierdipped in 24% sucrose and a more comfortable, padded, and physiologicrestraint can be useful in decreasing distress and pain.
Key words: dorsal penile nerve block, circumcision, neonatal pain.
Routine neonatal circumcision, when performed without anesthesia, is a painful and stressful operation.1 There is stilla pervasive belief that infants do not experience pain, or ifthey do, they do not experience it in the same manner as seenin adults.7 The physiologic effects of this pain have beenwell documented and have been widely utilized to study the effectsof techniques to decrease the pain and stress.2,3,5,8
The rate of circumcision in the United States is unlikely to decrease, particularly after the 1989 American Academy of PediatricsTask Force on Circumcision statement that found evidence of advantagesand disadvantages to this most commonly performed operation15,16which is quick, safe, and has low morbidity.17 It is incumbentupon physicians to continue to search for safe and effective methodsof analgesia/anesthesia.
The dorsal penile nerve block (DPNB) was first described for use in the neonatal circumcision in 1978.18 Since then, multiplestudies have demonstrated both its safety and efficacy.5,8In a recent prospective report of short-term complications, nosignificant complications were noted with the use of DPNB in morethan 7000 infants during an 8-year period.19
Other methods of anesthesia and analgesia have been reported such as eutectic mixture of local anesthetics (EMLA, Astra PharmaceuticalProducts, Inc, Westborough, MA),20 acetaminophen,21 music,22oral sucrose,23 topical lidocaine,24,25 and local foreskininjection of lidocaine.26 However, none of these methods hasbeen shown to be statistically superior to DPNB in decreasingdistress. In addition, reported studies with these techniqueshave been too small to answer questions of safety.
The DPNB is the most utilized procedure, despite its shortcomings of adding time, the additional discomfort of a needle injection,and the associated learning curve. For these reasons, this studyfocused on improving this technique rather than pursuing othermethods of anesthesia. As stated in 1988,5 if circumcisionsare still to be performed, we owe it to our children to performthem as humanely as possible.
Three additional techniques were studied to assess their contribution to decreasing the neonate's pain and distress duringcircumcision as measured by behavioral scores and plasma cortisol.
Male newborn infants from Group Health, Inc (GHI) who were already scheduled for a routine neonatal circumcision at FairviewRiverside Medical Center, a community hospital in Minneapolis, were screened for study entry in 1993 to 1994. GHI is a prepaidstaff-model health maintenance organization with more than 240 000members in the Twin City area.
Inclusion criteria included: 1) age greater than 20 hours; 2) uncomplicated vaginal or caesarean birth; 3) weight between3000 and 4000 grams at birth; 4) a 5-minute Apgar score of greaterthan or equal to 8; 5) a full-term infant defined as a greaterthan or equal to 37-weeks-postconception age by the Ballard assessment;276) a normal range score on the Littman-Parmelee Obstetric ComplicationScale28; and 7) a normal physical exam by a pediatrician.
Informed consent was obtained from the parents of all infants and the study was approved by the Institutional Review Boardsof GHI, Fairview Riverside Medical Center, and the Universityof Minnesota. There were no added charges to the parents who agreedto participate, nor were there any incentives offered. The studywas funded by the Group Health Foundation.
Due to a change in methodology from 19885 in preparing the infant, injecting the anesthetic, and soothing the neonate,a pilot project of five infants was completed. Several routinetechniques were studied to determine their effect on modifyingthe stress and pain during circumcision: 1) all injections weregiven with the infant lying in their bassinet, 2) the iodine antisepticsolution was warmed to body temperature, and 3) there was no forcedprolonged fasting. The restraint device that was used remainedthe Circumstraint (Olympic Medical Corporation, Seattle, WA),a rigid molded-plastic platform that restrains the infants' extremitiesin a position of extension. The infants were repeatedly offereda pacifier by an attendant nurse, and the infants' arms were swaddledagainst their chest with a soft receiving blanket.
The data obtained from this first pilot study failed to demonstrate a significant reduction in behavioral scores or cortisollevels compared with 1988 data.5 Therefore, a second pilotof seven infants was performed utilizing standard DPNB in conjunctionwith a new restraint device, offering a pacifier dipped in sucrose,and buffering the lidocaine with sodium bicarbonate. The resultsfrom the second pilot study did show a significant reduction inbehavioral distress and a tendency toward lower cortisol levels.A study was then undertaken to determine which of these threeadditive techniques was responsible for the reduction in distress.
Eighty infants were randomized to four equal groups of 20. (A fifth arm of the study [24% sucrose pacification without DPNB]was abandoned after enrolling only 3 patients due to high behavioraldistress scores in the 3 infants, parents' concern about the lackof pain control, and the fact that DPNB is so well an acceptedpractice in the study hospital that it made enrollment into thestudy very difficult.) All subjects were injected for the DPNBin the bassinet, were prepared with warmed iodine solution, andhad no forced fasting period preoperatively.
Group 1 (DPNB with new restraint, see Table 1) received a nonbuffered lidocaine injection, a pacifier dipped in water, andthen were circumcised on a newly designed restraint chair (USPatent #5 160 185). This restraint differs from the Circumstraintin that: 1) all areas that contact the infant are soft, cushionpadded, and adjustable to the size of the infant; 2) it allowsfree movement of the infant's extremities without compromisingthe surgical field; and 3) it allows the infant to sit with hiships abducted and flexed, knees flexed, and head/trunk elevatedto 30 to 45 degrees with all its joints variably hinged for adjustabilityfor size of the infant and exposure to the perineum. The positioningof the baby in the restraint is more physiologic as it allowsfor the innate hypertonicity and flexion of the neurologicallyimmature neonate, and the velcro attached cushions allow accommodationto various sized infants (Fig 1 and Fig 2).
Group 2 (DPNB with sucrose) infants were continually offered a pacifier dipped in a 24% solution of sucrose (visually indistinguishablefrom water) beginning 2 minutes before the nonbuff-ered lidocaineinjection, and continuing until the infant was removed from therigid restraint.
Group 3 (DPNB with buffered lidocaine) infants were given a water dipped pacifier and then were injected with .8 mL of 1%lidocaine hydrochloride mixed just before the procedure with .2mL of sodium bicarbonate (1 milliequivalent per mL) to obtaina final pH of 7.4. The circumcision was performed on the Circumstraint.
Group 4 (control) served as the control group and infants were given a water-dipped pacifier, injected with nonbuffered lidocainefor the DPNB, and circumcised on the Circumstraint.
Both the study research assistant (L.B.) and the operator were blinded to the solution (water versus sucrose pacifier) andto which infants received the buffered lidocaine. Five differentexperienced pediatricians performed the 80 circumcisions. Thetechnique of DPNB injection utilized is described elsewhere.5,29
All manipulations (eg, bathing, physical examinations, blood tests) known to stimulate the hypothalamic-pituitary axis wereavoided for 1 hour before the circumcision.30 Beginning 2 minutesbefore the DPNB injection, each infant's behavior was recordedevery 30 seconds by a research assistant (L.B.) trained to 94%(by Cohen's κ) observer agreement using the Brazelton's behavioralstate scale31 to score behavioral arousal and a second scalefor behavioral distress (see Table 2).
Five scoring periods were defined: 1) baseline preinjection: the 2 minutes immediately before injection of the DPNB; 2) injection:the 30 second intervals during which the DPNB injection was given;3) immediate postinjection: the 2 minutes after the injection;4) delayed postinjection: the next 2 minutes after injection;and 5) circumcision. Note, that there was a 5-minute waiting periodbetween the injection and the circumcision; however, in the lastminute the infants were being placed on the restraint and thesurgical instruments were prepared. Because these scoring periodswere of unequal duration, percent occurrence for each code ineach scoring period was calculated. Distress scores for each scoringperiod were computed by multiplying these percentages by the code'sweight shown in Table 2 and dividing by 100. A score of threeindicated continuous, sustained crying throughout that period,although a score of zero indicated no fussing or crying duringthat interval. The percentage of coding intervals asleep was calculatedfor the circumcision scoring period by summing the quiet and activesleep codes from the scale.
Thirty minutes after the beginning of the circumcision, a plasma cortisol sample was collected by heel stick puncture (.5mL) at the same time as the required metabolic newborn screeningtest. The blood was centrifuged, plasma extracted, and it was stored at -20 degrees Centigrade until assayed. The plasma wasanalyzed using a cortisol radioimmunoassay kit (Pantex Corporation,Santa Monica, CA. Note: Pantex Corporation is now known as BioAnalysis Corporation). This assay is highly specific for cortisolwith the interassay and intraassay coefficients of variation bothbelow 11%.
The distribution of sample characteristics across groups were examined using one-way analysis of variance (ANOVA) and χ² statistics, as appropriate. The distress scale data were analyzedusing four (groups) by five (scoring periods) ANOVA with repeatedmeasures on the second factor. Plasma cortisol and sleep datawere examined using one-way ANOVAs. Post hoc tests were computedusing Newman-Keuls formula. All findings described as statisticallysignificant had P values of less than .05.
Subjects in all four groups were comparable with regard to age at time of circumcision (mean = 35.1 hours), gestational age(mean = 39.5 weeks), birth weight (mean = 3.65 kilograms), maternalage (mean = 29.9 years), 5-minute Apgar score (mean = 8.94), obstetricalcomplication score28 (mean = 83.9), time since last feeding(mean = 1.19 hours), and duration of circumcision procedure (mean= 11.2 minutes). There were no significant statistical differencesamongst the four study group means for any of these eight variables.
Fifty-two (65%) circumcisions were performed by the Gomco method and 28 (35%) by Plastibell (Hollister, Inc, Libertyville,IL) with the distribution being similar across the four groupsby the χ² statistical analysis (P = .93). Sixty (75%) of the infants weredelivered by caesarean section and 20 (25%) vaginally; there wasno bias for any study group. Early discharge of vaginally deliveredinfants impacted their availability for the study.
There was no statistical difference in the distribution of subjects from the four study groups performed by any one pediatrician.
Seventy-five (94%) of the study infants were white, 3 (4%) were black, and 2 (2%) were Hispanic.
Because morphine-based anesthetic might influence the effects of sucrose, the use of morphine-based medications during laborand delivery were examined by group. There were no group differencesfor use of meperidine hydrochloride (n = 3), nalbuphine (n = 17),or intrathecal morphine (n = 24); 8 infants received naloxonehydrochloride at delivery. Results for behavioral and hormonaldata were similar with and without these infants included in theanalyses.
Behavioral Data
Table 3 displays the behavioral distress scores for each study group during each scoring period. The groups differed in thedegree of behavioral distress they demonstrated (P < .05), withboth the new restraint and the sucrose groups showing less distressthan the other two groups (P < .05) overall. The scoring periodsin which less distress was shown differed by group. Infants inall groups showed an increase in crying from preinjection baselineto the injection. Both the buffered lidocaine and sucrose wereexpected to decrease distress during the injection and/or allowthe infants to calm more rapidly in the minutes after injection.The results demonstrate this effect for sucrose (P < .05) butnot for buffered lidocaine. In the sucrose group, an effect wasobserved in the first 2 minutes after injection (P < .05) andnot during the injections. Both the infants on the new restraintand those given sucrose were less behaviorally distressed duringcircumcision (P < .05). In fact, infants in these groups werenot significantly more distressed during circumcision than theyhad been during the preinjection baseline period (P > .10).
Analysis of the percentage of time asleep during the circumcision, demonstrated a significant beneficial effect for both thenew restraint and sucrose groups. Infants in the new restraintgroup slept through 57% and those in the sucrose group slept through 48% of the circumcision scoring intervals, compared with 29% and 26% for the buffered lidocaine and water control groups, respectively.
Cortisol Data
In previous work examining the effects of DPNB on cortisol responses in circumcision,5 the average cortisol level 30 minutesafter the beginning of circumcision was 386 nmol/L (14.0 µg/dL),with a standard error of the mean (SEM) of 36 nmol/L. In the presentstudy, the groups did not differ in plasma cortisol levels 30minutes after the beginning of circumcision (P > .10) (Table 4).The mean cortisol level averaging throughout groups was comparableto the earlier study results, 403.4 nmol/L (14.6 µg/dL) with aSEM of 24.8 nmol/L.
Substantial clinical experience and basic research documents that neonates are capable of experiencing and perceiving pain.1Frequently, physicians who perform neonatal procedures deny theirpatients anesthesia and analgesia even though it has been stronglyrecommended by the American Academy of Pediatrics.32
DPNB has been utilized since 1978 to decrease the pain and stress of neonatal circumcision. It has been shown to be effectiveand safe.5,8 Since the mid-1980's, DPNB has been used bythe pediatricians at GHI for more than 10 000 neonatal circumcisions.Despite the definite decrease in pain and stress for most infants,an occasional infant does not get significant relief from DPNBalone and many seem more uncomfortable than the physician andparents would like. For these reasons, this study was undertakenin an attempt to document other techniques that would lessen thedistress of circumcision and thus make it more humane.
Oral sucrose for analgesia in neonatal circumcisions was first explored by Blass and Hoffmeyer23 in 1989. They demonstratedmore than a 50% reduction in crying with infants sucking on a24% solution of sucrose during the circumcision. Reproducing theearlier findings of Gunnar et al,33 they found that nonnutritivepacifier sucking also attenuates the distress. Blass and Smith34later went on to show that sucrose is superior to other sugars(lactose, glucose, and fructose) in calming crying infants. Itis felt that the calming/analgesia effect is not at the molecularblood-brain barrier, but rather that sucrose stimulates the opioidpathways in the brain by its sweet taste.
In this study, sucrose was helpful and additive to the analgesic and anesthetic effects of the DPNB during the immediate postinjectionperiod and the circumcision itself. Although initially included,the arm of the study using sucrose alone for pain relief withoutDPNB, had to be abandoned attributable to parent and researchassistant concerns with the lack of adequate anesthetic effect.Based on this experience and the results of this study, the useof sucrose as an adjunct to DPNB seems to be an effective useof this modality that is acceptable to care givers and parents.
Our group has now adopted the routine use of sucrose with all circumcisions. A practical formula to prepare a 24% to 25% sucrosesolution involves mixing one packet of table sugar (commonly foundin restaurants, hospital cafeterias, and doctors' lounges) with10 mL of tap water. The sugar packets can be kept in the nursery,facilitating the mixing of solution just before the circumcision.A piece of gauze or a pacifier can then be dipped into the solutionand repeatedly offered to the infant before and during the DPNBinjection and circumcision.
We decided to study the effect of buffered lidocaine based on experience with adults in the emergency room setting showinglowered pain scores when local anesthetics were buffered withsodium bicarbonate before injection for laceration repair.35The pain of the injection was reduced but there was no reductionin anesthetic efficacy or onset of action. Buffering the usuallyacidic lidocaine hydrochloride (pH = 6.5) dramatically shortensits shelf life, thus the recommendation to add the buffer solutionjust before its use.36 Unfortunately, the infants in the studydid not seem to respond to this technique as did the adults, thusreflecting the difficulty in extrapolating from the adult painexperience.
Any physician or nurse who has attempted to extend the arms and legs of a term neonate to strap them into a rigid restraint,realizes the resistance to extension that all neonates possess.This is attributable to their neurologically immature unmyelinatedlong tracts causing their inherent hypertonicity. In an attemptto overcome this problem, one of the authors (H.J.S.) designeda new restraint that is more physiologically adapted to the neonate'stone, obviates the need to impale the perineum to prevent movement,and eliminates the cold hard plastic. Previous work by Maloneet al37 did not demonstrate that limb restraint was particularlyaversive, but data from this study clearly demonstrate a 50% reductionof distress during the procedure from the use of a physiologicallydesigned, cushioned soft circumcision chair over the rigid plasticrestraint (Circumstraint).
Although DPNB has the most extensive literature and experience supporting its use in neonatal circumcision, other modalitieshave been studied. EMLA can be a useful agent for pain management20in circumcision, but concerns about safety in newborns may limitits use. EMLA is not approved by the Food and Drug Administrationfor neonates because of the presence of prilocaine (one of thetwo anesthetics in the cream) which has been shown to induce methemoglobinemiain newborns. In addition, EMLA requires a prolonged (45 to 60minutes) application that may not fit the schedule of a busy practitioneror nursery service. The only comparison of EMLA to DPNB was ina small study of bupivacaine .5% used for DPNB compared with EMLAfor postoperative analgesia for circumcision in boys 2 to 10 yearsold.38 The conclusion was that EMLA was not as effective asDPNB for postcircumcision analgesia.
Oral acetaminophen was found to provide some relief of pain after the immediate postoperative period, but does not ameliorateeither the intraoperative or immediate postoperative pain.21Both classical music and intrauterine sounds have also failedto reduce pain as measured by behavioral and physiologic parameters.22
Topical lidocaine has also been shown to be efficacious and safe,24,25 but has not been directly compared with DPNB. However,Mudge et al24 found that infants treated with topical lidocainecried 74% as much of the time as those treated with placebo. In contrast, Stang et al5 showed that infants receiving DPNB criedonly 33% as much as those given placebo. In addition, topicallidocaine also has the same practical problems as EMLA. The applicationmust occur 20 to 120 minutes before the procedure making timingsuch an issue that it would be impractical in a busy practiceor nursery.
Local anesthetic injection into the foreskin itself as described by Masciello26 in 1989 was shown to be effective in attenuatingpain responses, but his data on a small number of patients hasnot been substantiated.
The Jewish ritual circumcision (brit milah) acknowledges the pain of this operation by assigning an attendant (the sandek)to hold and soothe the infant with sweet wine, which may havea similar effect to sucrose by stimulating opioid pathways (the12% alcohol may also benefit the infant with some sedation). Furtherstudy of the procedures utilized in the Jewish brit is warranted.
Surprisingly, our cortisol levels did not decrease as we had expected from examining preliminary data from our second pilot.With a baseline cortisol of 5.2 micrograms per deciliter underthe exact same study preconditions,39 an unanesthetized infantraises its cortisol to a mean of 17.0 whereas the level is decreasedto 14.0 with DPNB alone.5 In this study, the mean cortisolwas 14.6 micrograms per deciliter for the entire 80 infants, butthere was no significant difference between the study groups (see Table 3). This probably represents the fact that these manipulationshelp modify the stress and pain of circumcision but do not eliminateit.
In conclusion, if physicians are to continue to perform circumcisions, they should attempt to minimize the pain and stressof the procedure. In addition to the DPNB, allowing infants tosuck on a sucrose dipped pacifier, and placing them on a morecomfortable physiologically designed restraint can result in areduction in crying and increase in sleep behavior. By adoptingthese techniques and encouraging their use by others, physicianscan move beyond DPNB toward a more humane circumcision.
Received for publication Nov 4, 1996; accepted Jan 21, 1997.
Presented in part at the annual meeting of the Ambulatory Pediatric Association, San Diego, California, May 10, 1995.
Reprint requests to (H.J.S.) 1430 Highway 96, White Bear Lake, MN 55110.
Funding support came from the Group Health Foundation.
We are grateful to the neonatal Level 1 nursery staff at Fairview Riverside Medical Center for their help with this study,especially Marie Root, RN, who was instrumental in helping preservethe blinding of the procedures. We thank Richard Mandt, PharmD,and his pharmacy staff at Fairview for mixing the sucrose solutionsand providing us with the necessary medications for DPNB. We alsoappreciate the cooperation of the Fairview Laboratory for theirassistance in blood drawing and storage of the cortisol samples.
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