Anesth Analg 1987 Krane 647 53

7/30/2019 Anesth Analg 1987 Krane 647 53

1/7

ANESTH ANALG 6471987:flh:647-53

Caudal Morphine for Postoperative Analgesia in Children:A Comparison with Caudal Bupivacaine and Intravenous MorphineElliot J. Krane, MD, Law rence E. Jacobson, MD, Anne M. Lynn, MD, Carol Parrot, MD, andDonald C. Tyler, M D

KRANE EJ , JACOBSONLE, LYNN AM, PARROT C,TYLER DC. Caudal morphine for postoperative analgesiain children: a comparison with caudal bupivacaine andintravenous morphine. Anesth Analg 1987;66:647-53.W e compared the efficacy, durat ion, and side effects of pre-servative-free morphine injected in to the caudal space inchildren, with caudal bupivacaine and with intravenousmorphine administration for relief of postoperative pain.Forty-six children, ages 1-16 yr, were randomly assignedto receive intravenous morphine (control group), caudalbupivacaine (0.25%, 1 mllkg), or caudal morphine (0.5wixlml, 0.1 mglkg). In half the patients given caudal mor-phine, the morphine was mixed wit h a dose of lidocaineadequate to produce sacral analgesia, to confirm correct cau-dal injection of t he morphine . Caudal injections were per-formed at the end of surgery. Time until the first requiredpostoperative intravenous morphine dose was recorded for

each patient. The duration of analgesia U M S significantlygreater with caudal morphine (median 12 hr , P


2/7

ANESTH ANAL(.1987;66:647-53648KRANE ET AL.

Table 1. Pain Scores Used by Nurse Observers to Evaluate a Subject's Need for Supplemental Intravenous Morphine1 2 3 4 5

Laughing, Happy, contented, Calm or Mild-moderate pain: crying, Severe pain: crying,euphoric pl'lyful asleep grimacing, restlessness; screaming;can distract with toy, inconsolablefood, parent

evaluate the duration of postoperative analgesia andthe incidence of side effects after caudal preservative-free morphine, compared with postoperative caudalbupivacaine and with intravenous morphine, using adouble-blinded protocol and close, in-hospital obser-vation.

MethodsApproval of our Institutional Review Board was ob-tained. After informed parental and (where appro-priate to age) patient consent, 46 children, ages 1-16yr, ASA physical status 1 or 2, and undergoing elec-tive genitourinary or lower extremity orthopedic sur-gery, were randomly assigned to the control group,or to receive a postoperative caudal injection of eitherbupivacaine or preservative-free morphine, as de-scribed below. Preoperative or intraoperative narcot-ics were not administered to any patient. Halothaneor isoflurane, with or without nitrous oxide, was usedfor operative anesthesia. In patients randomized toreceive caudal injections, the injections were per-formed by one of the investigators at the conclusionof surgery, except for two patients receiving caudalmorphine in whom injections were made before sur-gery because application of a spica cast followed sur-gery.Caudal injections were made with the child in thelateral position with the hips and knees flexed. Theskin over the coccyx and sacrum was cleansed withpovidone-iodine solution and alcohol. After palpa-tion of the sacral cornua, a 22- or 23-gauge needle wasplaced into the sacral hiatus, identifying the epiduralspace by loss of resistance as the needle passed throughthe sacral ligament. After failure to aspirate cerebro-spinal fluid or blood, and a negative test dose in thebupivacaine group, the drug solution was injected.Patients were then extubated while deeply anesthe-tized and were taken to the postanesthesia recoveryroom while asleep. ?'he patients, their families, andthe nurses assessing pain were not aware of the treat-ment group assignment.

Treatment groups were as follows:Intravenous Morphine Group (Control, n = 15):

Children in this group did not receive caudal

injections. Morphine sulfate, 0.05-0.2 mgkg, wasadministered postoperatively every 2 hr as neededfor analgesia.

Caudal Bupivacaine Group ( n = 15): Children inthis group received a postoperative caudal in-jection of 0.25% bupivacaine with 1:200,000 epi-nephrine, 1 ml/kg (maximum dose, 25 ml). In-travenous morphine was later given as describedbelow.

Caudal Morphine Group ( n = 16): Patients in thisgroup were subdivided into two sections. Eightpatients received postoperative caudal injectionof preservative-free morphine alone (1 mg/mldiluted to 0.5 mg/ml with normal saline), in adose of 0.1 mg/kg. In order to confirm properplacement of the injecting needle in the caudalepidural space, the remaining eight patients re-ceived postoperative caudal injection of pre-servative-free morphine, 1 mg/ml, in a dose of0.1 m g k g mixed with 1% idocaine, 0.25 ml/kg.The lidocaine dose was calculated as being ad-equate to produce anesthesia in sacral derma-tomes (10). Anesthesia in sacral dermatomes inthe postanesthesia recovery room confirmedcaudal injection. Intravenous morphine was givenas described below.

For the first 24 hr after the operation each patientwas monitored for respiratory depression with a chestwall impedance monitor to detect apnea, and withhourly determination of respiratory rates. Naloxoneand resuscitation equipment were available at eachbedside for 24 hr after surgery.

When awake in the recovery room, patients in thebupivacaine and morphine-plus-lidocaine groups wereevaluated by an investigator for anesthesia to pinprickin sacral dermatomes. Two patients given caudal bu-pivacaine and one patient given caudal morphine-plus-lidocaine did not have a sensory block and weretherefore excluded from the data analysis, thus re-ducing the sample sizes to 13 in the caudal bupiva-caine group and 15 in the caudal morphine group.The efficacy of postoperative analgesia induced bycaudal bupivacaine and caudal morphine was com-pared with the efficacy of intravenous morphine (in


3/7

ANESTH ANALG 649AUDAL MORPHINE FOR ANALGESIA IN CHILDREN 1987;66:6.17-53

Ta b le 2 . Ag e s , Types of O p e r a t i on s , a n d T r e a t m en t G r o u p A s s i g n m e n t of Ex p e r ime n ta l SubjectsAge (yr) Operation" Duration of analgesia (hr)

Control group (intravenous morphine only)12315689101'11

12131415MeanMedian

I

Caudal bupivacaine gro up16"171819202122232425262728MeanMedian

Caudal morphi ne group w ithout lidocaine2930"313233343536MeanMedian

With lidocaine37383940414243MeanMedianMorphine group meanMorphine groupmedian

14165

14215

31910932

1317.8-351221422

1035102106.2

-13

7911116

16--29495

1112--7.7-

BunionectomyOsteotomyOsteotomyOsteotomyHypospadiasTibial tumor excisionOsteotomyOsteotomyOsteotomyHypospadiasOsteotomyTeno omyOsteotomyTibial tumor excisionHypospadias

HypospadiasHypospadiasOsteotom yOsteotomyOsteotomyOsteotomyHypospadiasOsteotom yOsteotomyHy pospadiasOsteotomyOsteotomyOpen fracture reduction

OsteotomyHypospadiasTen0 omyOsteotomyOsteotomyOsteotomyOsteotom yFemoral bone graft

Osteotom yFemoral Bailey rodsOsteotomyFemoral bone graftHypospadiasFemoral Bailey rodsOsteotomy

0 .511.75.0. 81 .80. 71. 55 .3(1.2

>240 .50 .30 .50.85 .52. 00.8

>243 .89.89 .94 .55 03. 93.7

10.010.311.05 .23 .56 .75. 2

20.5> 49. 75 .24. 06. 812.1

10.99. 910.3

12.115.718.016.623.64

16.714.416.612.612.1- .


4/7

ANESTH ANAL(;1937;66:647-53650 KRANE ET AL .

1v)I-z1aaLL0I-zw0awL

0 I V MORPHINE

0 BUPIVACAINE

o ! I I I I I I I I 1 I 10 4 8 12 16 20 24

TIME (HOURS)Figure 1 . Percentage of patients in each group who did not requiresupplemental intravenous morphine during the 24-hr observationperiod. One patient in each group required no intravenous mor-phine; these three patients do not appear on the graph. The mediantimes to first intravenous morphine dose for each experimentalgroup are marked by an asterisk, which also denotes P


5/7

CAUDAL MORPHINE FOR ANALGESIA IN CHILDREN ANESTH ANALG 6511987;66:647-53

Table 3. Frequency of Postoperative Complications in Each GroupIntravenous morphine Bupivacaine Caudal morphine

(n = 15) (n = 13) (n = 15) x' PRespiratory depression 0 0 0 - NSUrinary retention 3 2 4 1.03 NSNausedvomiting 5 4 7 1.36 NSPruritis 0 1 2 2.14 NS

Abbreviation: NS, no statistically significant difference.

In contrast, th e range of duratio n of analgesia aftercaudal morp hine was 4-24 hr. Th e ons et of analgesiaafter caudal morphine was apparently rapid; uponawakening from general anesthesia, every patient inthe caudal morphine g roup w as analgesic, with painscores of 1-3, and n one required intrave nou s mo r-phin e in the recovery room. Inde ed, on ly four of 15(27% ) audal morphine patients required supplem en-tal intravenous morphine within the first 8 hr afterthe operation : two of the se patien ts received intra-venous m orphine after about 4 hr, neither of w homhad confirm ation of co rrect caudal placem ent by in-jection of lidocaine; a third patient had otalgia be-lieved to be caused by operative use of nitrous oxide,and may have required morphine supplementationfor this reason. Eleven patients who received caudalmorphine (73%) maintained pain scores less than 4for 9 to about 24 hr. One patient required no anal-gesics in the 24-hr observation period, also after hy-pospadias repair. After the first 4 postoperative hr,most patients who had not needed parenteral mor-phine were in the caudal morphine group (Fig. 2).The duratio n of ana lgesia after caudal mo rphin edid not correlate with the age or weight of the pa-tients. There was a tendency for patients who re-ceived the m ixture of preservative -free mo rphin e withlidocaine to hav e a longer duratio n of ana lgesia thanthe p atients w ho received preservative-free morphinealone (mean 14.4 and 9.9 hr, respectively), but thiswas not statistically significant (P = 0.22).Patient and fam ily acceptance of caud al mo rphin ewas enthusiastic. Among patients who had under-gon e operation s of a similar natu re previously, en -thus iasm for the qua lity of analge sia provided by cau-dal morphin e was especially high, e ven at the expense,in the instance of one 16-yr-old boy, of bladder cath-eterization. In contrast, many parents of children inthe control group complained of inadequate analgesiaduring the first 24 hr after the operation.Cornplica ionsThere w as no statistical difference in the frequency ofcomplications amo ng the three groups (Table 3). All

patients who underw ent h ypospadias repair had rou-tine postoperative bladder drainag e. Am ong the otherpatients, intravenou s morphine alone was associatedwith a 25% incidence of urinary retention requiringbladder ca theterization (3/12 patien ts). Urinary reten -tion was slightly more common in the caudal mor-phine group (413 patients, 31% ), but two of thesefour patients received intravenous mo rphine prior totheir inability to void. O ne patient given caudal bu-pivacaine required catheterization more than once.Nausea and vomiting were common in all groups,and occurred in the caudal morphine patients priorto the administration of intravenous m orphine. T reat-ment with antiemetics was variably successful. Mildnasal pruritis occurred in two caudal morphine pa-tients, but did not require treatment. Respiratorydepression (respiratory rate less than lO/min) or ap -nea did not occur in any patient, although monitorfalse alarms were no t uncomm on.DiscussionThe caudal adm inistration of 0.1 mg/kg of preserva-tive-free morphine (with or w ithout 1% idocaine, 0.25m y k g ) after lower extremity or genitourinary surgerywas a s afe an d effective meth od of ach ieving pro-longed postoperative analgesia in children. Caudalmorphine provided approximately twice the durationof analgesia as caudal bupivacaine, w ithou t motor orsensory block. The onse t of effect of ca udal morph inein children was sufficiently rapid to p rovide analg esiain the recovery room a short time after the postop-erative caudal injection, such that all the children wh oreceived caudal morphine were analgesic upon arousalfrom general anesthesia, which w as within 15-20 m inof th e cauda l injections in m ost instances. This is anotable departure from experience with adult pa-tients, in whom the ons et of analge sia after lumbarepidural morp hine adm inistration requires about 1hr(14).Lidocaine was ad ded to the preservative-free mor-phine of half the caudal m orphine grou p patients toconfirm correct placem ent of the c audal needle bymea ns of a sho rt-acting dr ug that was n ot likely to


6/7

ANESTH ANALG652 1987;66:617-53 KRANE ET AL .

influence the outcome of the study. In so doing, weidentified one failed injection in the group of eightmorphine-plus-lidocaine patients. Although the ad-dition of lidocaine to the caudal morphine injectatetended to increase the duration of postoperative an-algesia, this increase did not reach statistical signifi-cance, and may have been a result of the inclusion oftwo patients in the group that received preservative-free morphine alone who may not have had true cau-dal injection of the study drug but in whom we didnot have the ability to make that determination. Elim-ination of these patients from the comparison of thosewho received morphine alone vs those who receivedmorphine with lidocaine further narrows the differ-ence in mean durations of analgesia between thosesubgroups of subjects (13.9and 14.4hr, respectively).

We made no attempt to compare the quality ofanalgesia conferred by these three methods of con-trolling postoperative pain. Presently there are no val-idated and accepted tools for measuring pain in smallchildren, and such a comparison must await the de-velopment of reliable pediatric pain scales. However,the subjective opinions of the hospital nursing staffwho care for postoperative children and of our sur-gical colleagues, all of whom were blinded to treat-ment group assignment, were that there was no de-crement in the quality of analgesia when comparingcaudal morphine to bupivacaine, and that both weresuperior to control patients, in whom pain followeda cyclic pattern.

The frequency of side effects tended to be higherin caudal morphine patients, though a proportion ofthe side effects might have been attributable to sub-sequent administration of intravenous morphine.Though naloxone has been reported to be effective intreating urinary retention and nausea associated withepidural morphine (15,16), we did not evaluate thisdrug in our patients. We observed no cases of delayedrespiratory depression, but our series is a small one.More experience with spinal narcotics in children willneed to be gathered to assess fully the risk of respi-ratory depression after epidural morphine, to identifysubpopulations at risk, to adequately inform familiesof risk, and to guide selection of appropriate drugdosage and monitoring technique. Until the full ex-tent of such risk has been defined in children, res-piratory monitoring should be used and equipmentand drugs for resuscitation should be at hand.Although it may be a laudable goal to eliminatepostoperative pain in children, there are some in-stances in which pain is a valuable symptom thatalerts the physician to the existence of a problem.During the course of this study, one orthopedic sur-geon believed that the motor and sensory block as-

sociated with caudal bupivacaine delayed the recog-nition of a compartment syndrome in one patient whohad undergone a tibial osteotomy, a recognized com-plication of this operation. After that experience, wechose not to administer caudal bupivacaine for post-operative analgesia after tibial osteotomies. It remainsto be seen whether caudal morphine confers analgesiasufficient to blunt the intense pain of the tissue isch-emia associated with compartment syndromes, butbecause caudal morphine does not ordinarily resultin motor blockade, the loss of voluntary movementdistal to a compartment syndrome should remain adiagnostic tool for the surgeon.In 1981 Jensen (17)published the first and, to date,only report of caudal morphine for control of post-operative pain in children. In that study, caudal mor-phine (0.05 mg/kg) was compared to caudal bupiva-caine (0.2570,.5 mVkg) in young boys after outpatientcircumcision or inpatient hypospadias repair. Onlythe inpatient group was evaluated for duration of an-algesia. As in our experience, all patients except onewith a failed block were analgesic in the recoveryroom. Jensen reported a duration of analgesia of 4-8.5hr (mean 6 hr) after caudal bupivacaine in five chil-dren, and 5-37 hr (mean 20 hr) after caudal morphinein seven children. The incidence of nausea was similarin the two groups, but other side effects or compli-cations were not studied. Unlike our study, a controlgroup was not included, respiratory monitors werenot used, nor is it specified how efficacy or durationof effect were determined. Therefore, our data con-firm the results of Jensen, further demonstrate theefficacy of caudal morphine for analgesia after bothgenitourinary and orthopedic surgery in a wider agegroup, and demonstrate the absence of significantside effects compared to a control group receivingconventional parenteral narcotics.

In summary, caudal preservative-free morphineprovided prolonged analgesia of longer duration thancaudal bupivacaine and without side effects greaterthan those seen with conventional parenteral mor-phine, in children after lower extremity orthopedicand genitourinary surgery. Because a needle may beplaced within the caudal space more easily than inthe lumbar epidural space in children, and becauseof the present unavailability of appropriately sizedepidural needles for pediatric use, caudal injectionsor caudal catheters may be the preferred route foradministration of epidural narcotics in young chil-dren.

Duramorph provided by the A . H. Robins Comp any.


7/7

CAUDAL MORPHINE FOR ANALGESIA IN CHILDREN ANESTH ANALG 6531987;66:647-53

References1.

2.

3.

4.5.6.

7.8 .

9.

Magora F, Olshan g G, Eimerl D, Shorr J, Katzenelson R, CotevS, Davidson JT. Observations on extradural morphine anal-gesia in various pain conditions. Brit J Anaesth 1980;52247-32.Cousins MJ, Mather LE. lntrathecal and epidural administra-tion of opioids. Anesthesiology 1984;61:276-310.Cohen SE, Woods WA. The role of epidural morphine in thepostcesarean patient: efficacy and effects on bonding. Anes-thesiology 1983;58:500-4.Schechter NL. Status of pediatric pain control. Pediatrics 1986;m11-5.Mather L, Mackie J . The incidence of postoperative pain inchildren. Pain 1983;15:271-82.Jon es SEF, Beasley JM, Macfarlane DWR, Davis JM, Hall-Dav-ies G. Intrathecal morphine for postoperative pain relief inchildren. Br J Anaesth 1984;56:137-40.Shapiro LA, Jedeiken RJ, Shaler D, Hoffman S. Epidural mor-phin e analgesia in c hildren. Anesthesiology 1984;61:210-2.Dalens B, Tan guy A, Haberer J-P. Lumbar epidural anesthesiafor operative and postoperative pain relief in infants and you ngchildren. Anesth Analg 1986;65:1069-73.McGown R C. Caudal analgesia in children. Five hun dre d cases

for procedures below the diaphragm. Anaesthesia 1982;37:10. Arthur DS, McNicol LR. Local anaesthetic techniques in pae-diatric surgery. Br J Anaesth 1986;58:760-78.11. Kay B. Caudal block for postoperative pain relief in children.Anaesthesia 1974;29:6104.12. Matsumiya N, Dohi S, Takahashi H, Kondo Y, Naito H . Car-diovascular collapse in an infant after caudal anesthesia withlidocaine-epinephrine solu tion . Anesth Analg 1986;65:1074-6.13. Schulte-Steinberg 0.Neural blockade for pediatric surgery . In:Cou sins MJ, Bridenbaugh, PO, eds . Neural blockade in clinicalanesthesia and management of pain. Philadelphia: Lippincott,1980:508.14. Bromage PR, Camporesi E, Ches tnut D. Epidural narcotics forpostoperative analgesia. A nesth Analg 1980;59:473-80.15. Rawal N, Mollefors K, Axelsson K , Lindgardh G, Widman B.An experimental study of urodynamic effects of epidural mor-phine and of naloxone reversal. Anesth Analg 1983;62641-7.16. Rawal N, Wattwil M. Respiratory depression following epi-dural m orphine. An experimental and clinical study. AnesthAnalg 1984;63:8-14.17. Jensen BH. Caudal block for post-operative p ain relief in chil-

dren after genital operations. A comparison between bupiva-caine and mor phin e. Acta Anaesthesiol Scand 1981;25:373-5.

805-18.

Anesth Analg 1987 Krane 647 53

Documents

Transcript of Anesth Analg 1987 Krane 647 53