Epidural opioids during laminectomy surgery for postoperative pain

Epidural Opioids during Laminectomy Surgery for Postoperative Pain Denis L. Bourke, MD,* Edward Spatz, MD,? Ronald Motara, MD,$ Joe I. Ordia, MD,9 James Reed, MD,§ James M. Hlavacek, MD11 Boston University, Departments of’ Anesthesiology and Neurosurgery, MA; Department of Anesthesiology and Critical (Iare Medicine, Johns Medical Institutions, Baltimore, MD.

*Associate Professor of Anesthesiology, Johns Hopkins Medical Institutions TProfessor University

of

Neurosurgery,

Boston

fAssociate Professor of Neurosurgery, ton University

Bos-

DAssistant Professor of Neurosurgery, ton University

Bos-

(IAssistant Professor of Anesthesiology, ton University

Bos-

Received for publication September 19, 1991; revised manuscript accepted for publication December 9, 1991. 0 1992 Butterworth-Heinemann J. Clin. Anesth. 4:277-281,

199‘2.

Study Objective: To determine whether morphine upplied directly to the dum during laminertomy surgery jnovides szlperior postopemti-i)eanalgesiu durinCg the first 24 hours. Design: Randomiied, double-blind study. Setting: A uni7lersit?r-~~~liuted hospital. Patients: Twenty ASA physical status I and II patients ages 18 to (70 yearx Interventions: Simultaneous topical dural upplication and intramuscular (IM) in jrctiort of unknown solutions of saline and morphine 3 mg. Measurements and Main Results: Postoperative analgesia mas a~ssessed using the 7icuctl (~mlog scde (VAS), n modified McGill-Meltack pain questionnaire, subjective nursing e-ocllucltion.c, and the amount of supplemental analgesic medication used. FCCtiwts uvre obserued for complications and side effects. Compared with the patient,s who r-ecei-ied epidurnl saline and IM morphine, the patients who received epidural morphine and IM .saline had less postoperative pain as determined by VAS .scores, nursing ovaluations, and amount of supplemental opioid unalgesir dose.s (1.6 -C I.2 vs. 4.1 ? I.2 analgesic doses per patient; pCO.05) required in the first 24 hours. Minor ,side effects were similar- for the two groups. No patient dtweloped respiratory depression. Conclusions: Morphine 3 mg applied topic&y, to the dura at the end of laminectomy .surgeq W a simple, safe, and effective way_ of provzding improved p&operative analgesia.

Keywords: Pain,

Reprints will not be available. Address correspondence to Dr. Bourke at the Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21205-2181, USA.

Boston, Hopkins

postoperative;

analgesia;

opioids,

epidural;

laminectomy.

Introduction Since the discovery of opioid receptors in the spinal cord, epidural opioids have been used widely to treat both acute and chronic pain.‘-” Epidural opioids can provide profound postoperative analgesia with less central and systemic side effects than opioids administered by the traditional intramuscular (IM) and subcutaneous routes, and they may be superior to intravenous (IV) patientcontrolled analgesia techniques. *-* With increased experience and improved knowledge of appropriate dosage, fears of delayed respiratory depression have proved largely unfounded. The frequency of respiratory depression after epidural opioids may in fact be no greater than respiratory depression following opioid administration by other routes.“-” J. Clin. Anesth., vol. 4, July/August 1992

277

Original Contributions This study was designed to determine whether morphine applied directly to the dura at the time of’surgical laminectotny could provide patients with improved postoperative analgesia compared with the analgesia ohtained by a more traditional postoperative analgesic regimen of‘ IV and IM morphine. Materials

and Methods

With Boston University Hospital Human Research (Iotttmittee approval and informed consent, we studied 20 ASr\ physical status I and II patients between the ages of’ 1X and 60 scheduled for elective lumbar latnittectotn~~. Patients were excluded from the study if symptoms had existed for more than 2 years, if’ the patients had had previous back surgery, or if’they had taken opioid ana1gesic.s during the week prior to surgery. During the preoperative visit, patienls were asked to complete a modified McGill-Melzack pain questiottnairr and to indicate their current pain level on a visual analog scale (VAS).‘? On the day of surgery, all patients were premeditated with diazepam IO mg orally a~ 6:OO ,\.&I. f\ll operations began between 7:30 and 9:OO .\.%I. Anesthetic management was stattdardiLet1. ~l‘hiopctttal sodiurtt 3 to .3 mg/kg and suc,cinylcholitte 1 tttgikg wet-t used f’or induction. Anesthesia was maintained with entlurane, nitrous oxide, and pancuronium. Neuromuscular relaxatiott was reversed with neostigttnine and alropitie al the conclusion of surgery. Opioids were not Ltsetl either preoperatively or ititraoperatively. B&jre closure began and after final irrigalion atttl hemostasis, the surgeon deposited 6 tnl of’solution into the wound, onto the dura, and allowed it lo stand fi)r 5 minutes. .I‘he control, or lM, group (II = IO) received (i 1111 of’normal saline, whereas the epidural group (II = 10) received a ti ml solution containing 3 mg of‘ tnot.phine. At the same time, each patient received an IM injection of either saline or morphine 3 mg; patients who rdceived epidural morphine were given IM saline, and patients who received epidural saline were given IM ttiorphitie. ‘Ilie solutions were prepared and labeled by SUP an independent physician. All study participants, gems, anesthesiologists, nurses, and patients were blinded to the contents of’each solution. Slatidard posLoperative analgesic medicalion was ordered for all patients. In the recovery roottt, patients received morphitte 0.03 mgikg- IV as needed. At‘ter leavthe remainder ing the recovery room and throughout 01’the s,tudy period, lyatients received (1.I to 0.15 nrgikg of’ morphine IM every 3 hours as requested. Pain was evaluated and recorded at recovery room discharge, at 6:OO P.M., at midnight, and at noon on the day following surgery. Nurses scored patients’ pain as none, mild, moderate, or severe. Patients evaluated their pain using both the modified McGill-Melzack pain questionnaire and the VAS. Nurses observed patients at at least a-hour intervals for complications, including pruritus, urinary retention, excessive somnolence, and respiratory depression, throughout the immediate 24-hour postoperative period. 278

J. Clin. Anesth.,

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1992

Statistical analysis of the data included analysis of‘variante (ANOVA), l-tests, linear least mean squares regression, Mann-Whitney U tests, and the Spearman rattk correlation coefficient. Corrections for multiple comparisons were used when appropriate.“‘,” Statistical significance was set as the probability of’ a ‘I‘ype I error being ~0.05. All dala are reported as means * SD unless otherwise noted. Results The demographic data for the IM and rpidurai groups were similar (Table I). ?‘wo patients in the epidural group had adult ortset diabetes controlled with oral hypoglycemic medication. One patient in the IM group had diabetes, and one patient had well-controlled hypertension. Three patients in the epidural group and two in the placebo group had used opioid analgesics for their pain; however, none had used opioids in the 4 weeks beforr surgery. ‘I‘het-e kverr no iti1.raoperative surgical or attesrhrtic cotit~~lic~atiotts. Surgical time was sitnilar tix- both groups. a\,ei-aging 2.7 I- 0.5 hours (range 1.5 to -I hours). ;\I1 palirnts arrived in the postanest hesia c are unit I,) 12: 30 discharged to the ttt~urosurgic~al ttrtrsittg P.V. anti ~vere unit 1,~ 3:OO 1’.31. In ;tte postopet~aTive period, one patient iii tlit, epid~~ral group developed prurittts. which responded to Z.‘, ~rtg of‘ tlif’hettttydr;tttlinr hvdrochloride IM. I‘het-e I~;IS no rvidcttc-t, of nausea. votitititig, ut-itiarv refentiott, 01. respiratc~r~. depressiott itt either group. In particular. no p;tGenl in either group exhibited a respiratorv rate of’ less than 12 breaths per ttiitiute al anv tittie during the stud) periotl. Kttiettts in tlic cpitlural group required sigttiGc’ittltl\, Icss tolal opioitl analgesic tttedic~atioti I’rottt the tbttd of sltrgery until noon the fi)llowing day than did patients in the IM group ( 1.h 57 1.2 analgesic- doses vs. I. 1 ?z 1.L’ analgesic doses per patient. or 14.0 t 10.5 mg of‘ mot-phitte pet- patiettl vs. 39.1 -t I 1.5 rng of tttorphine pet palient; ttiediati \,alues were one anti fi)rtt- doses, rc’spt” Lively). ~l‘hey also required fewer analgesic tttedicatiotts than did the IM patients in each of the titne periods (recovery room stay. recover-y worn until midnight. and ttii~liiiglit trntil ttooti; Tfddr 2). ,NIIIXS c~~nlitatetf I he epidural patiettta‘ pain ;IS sigttific.;tttti~ ICSS that1 the IM patients pain at discharge> tl-otn the rcc-o\ery i~oo~ii, at 6:OO t’.v., mid at tttidttighl. However-, thtat-c:was tto sigttilicant dil’ttrettcr in the nurses the day af‘trr e\,aluations of the two groups’ pain by now surgery (7‘frhlr 3). Table

1.

lkt110gi

.iptiic lLt;i Epidural

Intramuscular

Intraoperative

Table 2.

Postoperative

Supplementary

Opioid

In Recovery

‘2 3

‘I‘otal

analgesic

doses

Note:

analgesia

was ordered

Supplementary

I‘otal doses

Table

3.

equals

the number

Nursing

Evaluation

during

of doses

Pain Evaluations

Midnight

until Midnight

until Noon

0 13

3 7 0 0 7*

time period

significantly

less than

to 0.15 mg/kg of moI-phine

times the number

of patients

receiving

intramuscular every

3 hours

those

group

(p < 0.05,

Mann-Whitney

U test).

as requested.

doses.

Pain Number

Nursing

et al.

Analgesics

1

as 0.1

of Patients’

Room

Supplementary

7 3

doses*

“7 otal supplementar\

Recovery

Room

Receiving

0

6 4 0 0 4*

3

of Patients

1

13

2

Bourke

6 2 doses”

Epidural 0

morphine:

Requirements

Number

Number of Doses of Supplementary Analgesics

‘I‘otal

Analgesic

epidwal

In Recovery

Room*

of Patients

Recovery

Room

in Each

Pain Group

until Midnight*

Midnight

until Noon

I tttl.itttlltS~~Ii1;lt~

None Mild Motbatc scvcrc Epidural N0nc IMild Model-ate Severe “Epidural

group

nursing

pain evaluations

were significantly

lower than

‘I‘here was no difference in the preoperative assessment of pain by the patients as measured by either the VAS or the McGill-Melzack pain questionnaire. Postoperatively, the epidural group’s VAS pain scores were significantly lower than the IM group’s scores at all times until noon the day after surgery (Figure I). The McCillMelzack pain questionnaire did not show any differences in the pain assessments of the two groups throughout the study period. There was a positive correlation between the nursing evaluation of pain and the VAS. As would be expected, the nursing evaluation of pain also correlated with the amount of pain medication administered. The McGillMelzack pain questionnaire did not correlate with either the nursing evaluation, the VAS, or the amount of pain medication administered.

intramuscular

group

evaluations

(p < 0.05, Mann-Whitney

U test).

Discussion For many years, there was little interest and very few advances in the management of postoperative pain. During the past decade, however, interest in the management of postoperative pain has been renewed.‘+17 Numerous reports have confirmed the effectiveness of epidural opioids in alleviating acute postoperative pain.i-x,lx Further, it appears that early and effective management of acute postoperative pain may reduce subsequent pain and, possibly, analgesic requirements.“‘-?’ We are not aware of any previous reports on the use or value of the intraoperative direct application of morphine to the dura for postlaminectomy pain. Our results indicate that the direct application of morphine 3 mg to the dura before the closure of the laminectomy wound J. Clin. Anesth.,

vol. 4, July/August

1992

279

Original

Contributions

nletit of Ihe efJ'ectiveness of pain t~ianageni~tit ..!I’It ma) be that the McGill-Melzack questionnaire is too complicated and tleGlet1 fi)r patients in the first I2 hours of reco\~er-~~from
Preop

RR

6PM

Time Periods

MN

1 Noon

??Intramuscular Figure 1. Visual analog scale (VAS) pain scores Ji~r patient5 receiving either epidural or intramuscular morphine 3 tng at the time of laminectomy wound closure. Asterisk indi-

cates a significantly (#I I 0.05) lower VAS scorr for the patients receiving epidural morphine at the end of the time period indicated. (Preop = preoperative; RR = recovery room.)

provides patients with superior postoperative analgesia f’or the first 12 to 24 hours, as compared with conventional administration of’postoperative opioid analgesics. The patients who received epidural morphine reported less pain on the VAS, they were evaluated as having less pain by their nurses, and they required less opioid analgesic pain medication in the immediate postoperative period. There were no major complications during the study, and minor complications such as pruritus, nausea, and urinary retention were virtually the same for the epidural and IM groups. None of’the epidural morphine patients exhibited any evidence of respiratory depression (respiratory rate less than 12 breaths per minute, cyanosis, or excessive somnolence). We had anticipated that the McGill-Melzack pain questionnaire would correlate with our other measures of pain and add more sophisticated, qualitative pain information. It did not. Because our other measures of pain--the VAS, nursing evaluations, and opioid useall correlated with one another, we are inclined to discount the McGill-Melzack scores. The VAS is probably the most widely used and universally accepted pain measurement tool; its value has been validated by many investigators.22 Likewise, the measurement of analgesic medication use provides a direct and powerful assess280

J. Clin. Anesth.,

vol.

4, July/August

992

el‘kcc.

wtiicli

t:xtentis

cottititori1~

aasociatd

ttiotptiiiir.

supports

tt;tw

had

morphine

\\,ill hale stil3slatttial t.rcc~,)t~,t.s,“~“’1’1

kytitl with the

the IV

or

hypothesis

:! Ihl

(0

4 ~OIII.

;ttlt~iitiisti~atiott that

plierits

cf‘fkcr 01 who

applieci lo the d11ra tiuring surgcr! opioid eftrcrs ;it spitial opioitl

flitIn omit \ttid\ 01 t-elatil-ely health) ttiitltlle-aged the tlirrc t applicarion of’ morphine to the tl\r~x dtiritig lattiitiectoni~ surgei-\ appeared to provitlft analgesia sttperior (0 (on\~entiotial parcnrera~ tnethocls iltlcl umpt2t~lt~ IO the epidural opioitl ;ulalgcsia tlelibertvl for lhr irrtrnetli;tlc~ Whoui through ati e},itlur;rl c-atheler. lx)sltqwt-2tiL.v [xrio(l. ‘l‘he greatrsl ;1~1~~;1ttf;i~c of 1hi\ I‘lw ~~rocwiurr tlot3 no1 clvl:l! te( titiiqtte is its simplicity. wti it etimiw;es the te:(hnical difticullie\ ,ttttl s\ll~gcl’~, I possible septic ha~artis of’inserring an rpitlut-a1 (atheter ititr;tof)“i.;tli~t’l~ to provide the benefits of~+tltrt-al opioid laiiiinectc~tn~ patients. ;Idatial,gesia l.ot- postoperativt ditionall\~, establishing a significatt~ Ie\,c,I ol’;malgeSi;r itItraoper;lt i\,el! ma) f’tirlhri- rrtiuc-c l)aiti :tttd :inalgesic i~eqriit~et~ietits by pre\,enting the ottsc’l Of tII(* ~X~iIl-Sp~lSll1-

tients.

pain

cvc-le.

“‘i’

References I. 2. ?I 4.

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6.

Intraoperative

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