Anesth Analg 2001;93:598-600
© 2001 International Anesthesia Research Society
PEDIATRIC ANESTHESIA
The Effect of Preoperative Epidural Morphine on Postoperative Analgesia in Children
François Kiffer, MD,
Agnès Joly, MD,
Eric Wodey, MD,
Philippe Carré, MD, and
Claude Ecoffey, MD
Department of Anesthesiology and Surgical Intensive Care 2, Université Rennes 1, Rennes, France
Address correspondence and reprints requests to Professeur Claude Ecoffey, Service d’Aneshésie-Réanimation Chirurgicale 2, Hôpital Pontchaillou, 35033 Rennes cedex 9, France. Address e-mail to cEcoffey.rennes{at}invivo.edu
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Abstract
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IMPLICATIONS: We examined the effects of preoperative epidural morphine associated with general anesthesia on postoperative morphine requirements. Twenty-one children older than 6 yr scheduled for major surgery were randomly assigned to two groups, a control group and an epidural group that received a single epidural morphine injection.
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Introduction
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In adult patients, epidural morphine gives better postoperative pain relief than patient-controlled analgesia (PCA) with IV morphine (1). Indeed, epidural morphine administered before surgery provides better postoperative analgesia with less morphine consumption than PCA IV morphine alone (2). Epidural opioids are commonly used for major surgery in children (3,4). There are no studies that have examined the administration of preoperative epidural morphine for major surgery in children. The aim of our double-blinded, randomized study was to determine the postoperative analgesic effects of epidural morphine when administered preoperatively for major abdominal and orthopedic surgery in children.
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Methods
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After approval by our institutional ethics committee and informed consent, 21 ASA I children >6 yr of age scheduled for elective major abdominal surgery or orthopedic surgery of lower limbs were investigated. The premedication was 0.3 mg/kg of rectal midazolam 60 min before surgery. After induction of general anesthesia, in a randomized allocation, the Epidural group (n = 11) received 30 µg/kg of epidural preservative-free morphine in a single injection through a 18-gauge Tuohy needle at a level of L3-4 interspace. The Control group (n = 10) had no puncture, but a dressing was put at L3-4 interspace identical to the Epidural group. General anesthesia consisted of thiopental, sufentanil (initial dose 0.2 µg/kg followed by a starting infusion dose 5 µg · kg-1 · h-1), one MAC of isoflurane in O2/N2O. Surgical incision occurred within 1 h after epidural morphine injection. When an increase in systolic blood pressure of more than 10% from the basal value before surgical incision, an increase in heart rate of more than 15% from the basal value before surgical incision (after correction of hypovolemia if present), and/or physical manifestations of pain (sweat, tears, or flushing) were observed, IV boluses of 0.1 µg/kg of sufentanil were administered every 5 min until they decreased. Anesthesia was maintained by an anesthesiologist who was not aware of group assignment. Termination of isoflurane administration was considered as the end of anesthesia.
The day before surgery, the children were instructed on how to use a PCA device (Abbott pump; Abbott Laboratories, North Chicago, IL) and to describe pain on a visual analogue scale (VAS). Children were encouraged to use PCA to maintain a satisfactory level of pain relief. After the completion of surgery, when the children were sufficiently awake to follow instructions, the PCA device was set and its use explained again. After titration with 50 µg/kg IV morphine boluses until a VAS score <40 mm during the first 30 min, the PCA was set as follows: boluses of 1 mL = 20 µg/kg with a lockout interval of 8 min. In addition, all children received 30 mg/kg of propacetamol every 6 h IV (the first injection was given 30 min before the end of surgery).
VAS pain scores, morphine consumption, and incidence of opioid side effects were assessed hourly over a 24-h postoperative period by blinded trained observers. The following variables were recorded: duration of anesthesia, total amount of sufentanil used during anesthesia, time between induction and first injection of morphine with PCA device, time between end of anesthesia and first injection of morphine with PCA device, cumulative number of morphine boluses per hour during the first 24 h, and VAS pain scores per hour.
On the basis of an estimate of 50% difference in morphine consumption during the first 24 h as previously reported in adults (2), it was determined that 20 patients would be required in each group to demonstrate a significant difference at the level with a power of 0.8. All the results are expressed as mean ± SD. Differences between the two groups in age, weight, duration of anesthesia, total intraoperative dose of sufentanil, and delay of first use of PCA device were compared using Student’s t-test. Statistical analysis for PCA morphine consumption was performed using analysis of variance for repeated measures, followed by Student’s t-tests with the Bonferroni correction when appropriate. The nonparametric Mann-Whitney U-test was used for comparison of pain scores.
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Results
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There was no difference between the two groups in patient demographics, type and duration of surgery, and total intraoperative dose of sufentanil (Table 1). The time between the end of anesthesia and the first injection of morphine with the PCA device was (Epidural group 5.4 ± 7.2 h versus Control group 3.4 ± 5.6 h). VAS pain scores (Fig. 1) and morphine requirements (Fig. 2) were significantly smaller in the Epidural group than in the Control group (P < 0.05). The incidence of opioid side effects was similar in both groups.
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Figure 2. Evolution of morphine requirements in both groups (mean ± SD). PCA = patient-controlled analgesia.
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Discussion
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In this study, single-shot preoperative epidural morphine combined with PCA provided better postoperative analgesia than PCA alone after major lower abdominal or orthopedic surgery in children >6 years of age. Although the time of the first request for IV morphine with PCA was not statistically different in the Epidural group, the VAS scores in the Epidural group were significantly better. In addition, the morphine consumption was less in the Epidural group and similar to that previously described in the adult studies (2,5). No patient required more than the maximum morphine dose. Although the efficacy of 30 µg/kg epidural morphine lasts 12 hours in children (6), a prolonged decrease in VAS scores was recorded until 24 hours, which is clinically useful.
The incidence of pruritus with epidural morphine is as frequent as 88% (5). However, no patients in our Epidural group reported severe pruritus. The incidence of nausea and vomiting reported in the literature has ranged from 8% (7) to 87% (4); indeed, the incidence in this study was frequent (63% in Epidural group; 60% in the Control group) and one child in each group required treatment with ondansetron. The delayed occurrence of nausea and vomiting in the Epidural group (6 of the 8 children) four hours after administration may have been because of rostral migration of morphine via the cerebrospinal fluid. The reported incidence of urinary retention also varies widely from 6% (8) to 50% (9). In our study the occurrence was small (one child in each group). Finally, in each group there was one child with respiratory depression (excessive sedation, bradypnea, and SpO2 <94%). Oxygen support without naloxone injection was the only treatment required in both cases.
In conclusion, the combination of preoperative single-shot epidural morphine and PCA morphine for major abdominal and orthopedic surgery in children may permit better analgesia, avoiding complications resulting from the use of an epidural catheter (10,11). Epidural morphine may be given as an initial booster to achieve rapidly effective analgesia in the immediate postoperative period, and the combination with PCA morphine would provide analgesia for the postoperative pain.
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Acknowledgments
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Supported, in part, by grants from "Fondation pour l’Avenir."
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References
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Eriksson-Mjöberg M, Svensson JO, Almkvist O, et al. Extradural morphine gives better pain relief than patient-controlled i.v. morphine after hysterectomy. Br J Anaesth 1997; 78: 10–6.[Abstract/Free Full Text]
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Nègre I, Guéneron JP, Jamali SJ, et al. Preoperative analgesia with epidural morphine. Anesth Analg 1994; 79: 298–302.[Abstract/Free Full Text]
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Lejus C, Roussière G, Testa S, et al. Postoperative extradural analgesia in children: comparison of morphine with fentanyl. Br J Anaesth 1994; 72: 156–9.[Abstract/Free Full Text]
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Kart T, Walther-Larsen S, Svejborg TF, et al. Comparison of continuous epidural infusion of fentanyl and bupivacaine with intermittent epidural administration of morphine for postoperative pain management in children. Acta Anaesthesiol Scand 1997; 41: 461–5.[ISI][Medline]
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Wheatley RG, Madej TH, Jackson IJB, Hunter D. The first year’s experience of an acute pain service. Br J Anaesth 1991; 67: 353–9.[Abstract/Free Full Text]
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Krane EJ, Tyler DC, Jacobson LE. The dose response of caudal morphine in children. Anesthesiology 1989; 71: 48–52.[ISI][Medline]
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Glenski JA, Warner MA, Dawson B, Kaufman B. Postoperative use of epidurally administered morphine in children and adolescents. Mayo Clin Proc 1984; 59: 530–3.[ISI][Medline]
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Attia J, Ecoffey C, Sandouk P, et al. Epidural morphine in children: pharmacokinetics and CO2 sensitivity. Anesthesiology 1986; 65: 590–4.[ISI][Medline]
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Wood CE, Goresky GV, Klassen KA, et al. Complications of continuous epidural infusions for postoperative analgesia in children. Can J Anaesth 1994; 41: 613–20.[Abstract/Free Full Text]
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Dalens B, Tanguy A, Haberer JP. Lumbar epidural anesthesia for operative and postoperative pain relief in infants and young children. Anesth Analg 1986; 65: 1069–73.[Free Full Text]
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Valley RD, Bailey AG. Caudal morphine for postoperative analgesia in infants and children: a report of 138 cases. Anesth Analg 1991; 72: 120–4.[Free Full Text]
Accepted for publication May 4, 2001.
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Abstract
Introduction
