Regional analgesia for postoperative pain in pediatric outpatient surgery

Regional Analgesia for Postoperative Pain in Pediatric Outpatient Surgery By Barry Shandling and David J. Steward Toronto, Ontario, Canada 9 Of 156 children undergoing elective inguinal herniotomy under general anesthesia, 81 also had a regional nerve block using Bupivacaine. All w e r e treated as outpatients and recovery was assessed by postanesthetic room nurses and by interrogating the parents as to the child's behavior at home. It was concluded that the use of supplemental regional anesthesia reduced the general anesthetic requirements and the need for postoperative analgesics, thereby providing more rapid recovery to normal activity. I N D E X W O R D S : Regional anesthesia; surgery; inguinal herniorrhaphy.

outpatient

UTPATIENT surgery for infants and children is rapidly gaining in popularityJ It is O most important, however, that the postoperative course for the outpatient should be uneventful and result in a rapid return to normal activities. 2 Pain following operation delays recovery, and increased morbidity including nausea and vomiting. 3 If systemic analgesic drugs are required, these may also produce unwanted side effects of drowsiness, nausea and vomitingJ Regional analgesic techniques provide some analgesia into the postoperative period and have been successfully applied for the management of postoperative pain. These techniques are very suitable for the outpatient) There is indeed a possibility that postoperative pain, as measured by requirements for analgesics, may be less after surgery performed under regional analgesia. 6 Regional analgesia alone is however, generally not very suitable for pediatric patients and is not often used in this age group. It seemed to us that there might be a real From the University of Toronto, Hospital for Sick Children, Toronto, Ontario, Canada. Presented before the 28th Annual Meeting of the Surgical Section of the American Academy of Pediatrics, San Francisco, California, October 13-14, 1979. Address reprint requests to Barry Shandling, F.A.A.P., University of Toronto, Hospital for Sick Children, Toronto, Ontario, Canada. 9 1980 by Grune & Stratton, Inc. 0022-3468/80/1504~9019501.00/0 Journal of Pediatric Surgery, Vol. 15, No. 4 (August), 1980

advantage for pediatric outpatients by combining the use of general anesthesia with the application of a regional block. This would provide for postoperative pain relief and also reduce the requirement for general anesthetic agents during the operation, thus resulting in a more rapid recovery to street fitness. Bupivacaine has a duration of action of 8 hr 7 that extends well into the postoperative period making this a potentially very suitable agent. Good postoperative pain relief for the outpatient might be expected to lead to a more rapid return to full activity less requirement for analgesics, therefore a more rapid return to a normal appetite and less nausea and vomiting. This is particularly desirable when the postoperative care is being provided by the child's parents and not by nurses. Early ambulation has also been demonstrated to result in improved wound healing. 8 MATERIALS AND METHODS We have studied 156 otherwise healthy infants and children undergoing elective inguinal herniotomy performed in the Outpatient Department. Eighty-one of these had a regional nerve block performed using Bupivacaine ( R N B Group). The mean age was 3-4 yr and the range from 11 mo to 7 yr. The age distribution is shown in Fig. 1. N o premedicant drugs apart from atropine were administered, as is our practice with all outpatient procedures. 2 Atropine was given i.v. or p.r. at induction of anesthesia. Anesthesia was induced by means of i.v. Thiopentone or rectal methohexital 9 depending on the patient's age and maintained with nitrous oxide and Halothane in oxygen. After the patient had been prepared and draped for surgery the ilioinguinal and iliohypogastric nerve were blocked in the region medial to the anterior superior iliac spine ~~ (Fig. 2). 0.5% Bupivacaine in a dose up to 2 m g / k g with 1:200,000 epinephrine was used. The additional time required for the surgeon to perform this block is about 60 see. The operation was then performed using Mitchell-Banks technique without opening the inguinal canal. In some patients early in our series we also infiltrated the region of the proximal spermatic cord to block the genital branch of the genitofemoral nerve when this region was exposed. Later this was abandoned when it was apparent that it was of doubtful additional benefit and constituted a potential cause of hematoma formation within the cord. After the sac was transfixed and ligated and its distal portion excised the skin was closed with three interrupted sutures of subcuticular catgut and collo-

477

SHANDLING AND STEWARD

478 REGIONAL ANALGESIA FOR POST-OP HERNIOTOMY

POST-OPERATIVE ANALGESIC REQUIREMENTS

AGE DISTRIBUTION (81 pts}

5o1

[ ]R.N.B.(81) J ~ CONTROL(75)

80-

40 tt of patients

p
I00-

30

% of patients 60-

20

n,s.

40-

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6mo2yr

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5-6 >6yrs

yrs

yrs

20-

Fig. 1.

P.A.R.

dion applied to the wound. The anesthetic was discontinued and the patient was transferred to the Post Anesthesia Room (PAR). Here the nurse in charge assessed the need for analgesic drugs and monitored the recovery of the patient. If deemed necessary codeine phosphate 1.5 m g / k g I.M. was given. The child was discharged home when fully awake (almost always at 1 hr postoperative). A questionnaire was given to each family to be returned after three days. The completed record provided details of the child's recovery to a normal status at home together with the incidence of postoperative morbidity (e.g., vomiting) and any need for analgesic drugs. The controls consisted of an exactly comparable group of infants and children, treated by the same methods but omitti~lg the regional block. Data for these patients had been obtained by an identical questionnaire for another study. In Grder to minimize variables the same team of surgeon and anesthesiologist was involved with every patient.

RESULTS

Eighty-one questionnaires were returned by parents of children in the R N B group and were correlated with data from the P A R nurses' notes. The requirement for analgesics is shown in Fig. 3. In the control group, 74 of 75 patients were given codeine in the PAR compared with only 3 of 81 in the R N B group. At home analge-

Fig. 3.

sics were given by the parent to 32 of 75 of the children in the control group and 24 of 81 of the children with RNB. Fifteen o f seventy-five in the control group vomited (Fig. 4) at some time in the first 48 hr postoperative, 9 of 81 in the group with regional block vomited. This difference is not significant. The status of the child on the evening of surgery is shown in Fig. 5. Return to a bright and alert status and to normal activity was seen in a significantly greater number of children with RNB. Return to a normal appetite was not different in the two groups. The only complication of the regional nerve block was a transient motor block of the femoral nerve in 3 of the 81 patients. This caused a INCIDENCE % 30-

J~;~ R.N.B. (81)

D

20-

<:~

C)/

WITH

10-

Fig. 2.

OF VOMITING

(first 48 hours)

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AREAINFILTRATED LOCALANALGESIC

HOME

Fig. 4.

CONTROL (751

REGIONAL ANESTHESIA

479

STATUS OF PATIENT EVENING OF SURGERY

10080-

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normal

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R.N.B. (81) [ ] CONTROL (75) ~ 1 Fig. 5.

short-lived difficulty with walking. No infections, hematomas, or reactions to Bupivacaine developed. DISCUSSION

The problem of postoperative pain and its management is one that traditionally has been neglected or relegated to junior medical staff and/or the nurses. Even after the most minor surgery, however, pain is an unpleasant problem for the patient. Apart from the immediate discomfort, pain or the drugs required for its relief may secondarily cause other postoperative problems. For the outpatient and his/her parents these problems may be especially troublesome. Nausea and vomiting have been shown to be related to postoperative pain. 3 All the widely used analgesics may result in an increased incidence of nausea and vomiting together with drowsiness, 4 symptoms especially undesirable for the outpatient. Pain, if it restricts movement, may delay wound healing. 8 Reporting studies of the efficacy of regional analgesia for outpatient procedures in adults refer to the reduced requirement for analgesics extending throughout the postoperative period. 6 We have also observed that patients who have had surgery performed under regional nerve block suffer less postoperative pain than do those operated upon under general anesthesia--even after any effects of the local anesthetic have dissipated. Whether this is due to the more gentle technique applied by the surgeon operating under local analgesia or is a result of the

effect of the nerve block in decreasing the initiation of pain pathways in the central nervous system remains to be established. The regional nerve block may even conceivably modify the local effects of surgical trauma. The low incidence of postoperative complications and the satisfactory wound healing following surgery using regional analgesia has also been commented upon by several authors. 6'11 Regional analgesia has never been widely accepted for pediatric surgery. Therefore we chose to combine the advantages of general anesthesia for the surgical procedure together with regional analgesia to provide for postoperative analgesia. In addition, by performing the block before making the incision we wished to take advantage of the analgesia provided to reduce the general anesthetic requirements (an important consideration for the outpatient to whom the least possible dose of all depressant drugs should be administered), and also to obtain the unproven advantage of an afferent nerve block during surgery in modifying the amount of pain in the postoperative period. Bupivacaine was chosen as the local analgesic agent because of its long duration of action and its wide margin of safety. 12 Early in our series we decided that the patients who received infiltration of local anesthetic solution into the region of the proximal spermatic cord showed no improved postoperative analgesia over those who only had a block of the ilioinguinal and iliohypogastric nerves. Accordingly, in view of the risk of producing a hematoma in the cord we discontinued the injection of local anesthetic into the region. The marked reduction in requirement for analgesics in the PAR in the RNB group indicates that an adequate nerve block of the inguinal region was achieved by our method. We find that children over 6 mo of age almost invariably require some postoperative analgesic if they are to settle quietly following inguinal hernia repair. Struggling, crying, and restlessness in the immediate postoperative period may result in bleeding into the wound and delay healing. We note that in some centers less analgesics are required in the PAR but that usually in this case narcotic analgesics have been included in the preoperative medication or as a part of the anesthetic technique. For outpatients, we prefer to omit

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narcotic a n a l g e s i c p r e m e d i c a t i o n and also avoid these drugs d u r i n g s u r g e r y so as to ensure a r a p i d recovery postoperatively. M o s t of the children in the R N B group were quiet a n d pain free in the P A R and did not require s y s t e m i c analgesics. W e conclude t h a t the m o r e r a p i d r e t u r n of these children to a n e a r n o r m a l status at home was due to f r e e d o m from pain a n d the side effects of analgesic drugs. W e a r e d i s a p p o i n t e d t h a t the lower incidence of vomiting in the R N B group did not achieve statistical significance; possibly this will b e c o m e a p p a r e n t in a larger series. M a k u r i a et al. 6 did show a significantly r e d u c e d r e q u i r e m e n t for a n t i e m e t i c s in their patients o p e r a t e d upon under local analgesia. Postoperative vomiting is more c o m m o n in p e d i a t r i c patients than a d u l t s and is r e p o r t e d to occur in 15%-20% of patients having h e r n i o t o m y . 13'14 A n y technique which m i g h t offer a reduction in this distressing c o m p l i c a t i o n is to be considered worthwhile. T h e d e c r e a s e d use of analgesic p r e p a r a t i o n s at

home for the children in the R N B group t h o u g h again not quite achieving statistical significance would a p p e a r to point to a f r e e d o m from pain that extends well into t h e postoperative period. P a r e n t s of both the R N B a n d the control groups were given identical instructions concerning the a d m i n i s t r a t i o n of analgesics. T h e only complication which was observed was a t r a n s i e n t motor block of the femoral nerve in t h r e e patients. W e consider that this was p r o b a b l y d u e to the local analgesic solution t r a c k i n g within fascial planes. M o t o r block could possibly be avoided by the use of a m o r e dilute solution of Bupivacaine (e.g., 0.25%), however in this case the onset or the desired sensory block would be less rapid. 12 W e conclude t h a t the use of regional nerve block to s u p p l e m e n t g e n e r a l anesthesia and provide for postoperative a n a l g e s i a is a d v a n t a geous for the p e d i a t r i c outpatient. This will result in m o r e rapid recovery to n o r m a l activity and m a y reduce postoperative m o r b i d i t y .

REFERENCES 1. Shah CP: Personal communication. 1979 2. Steward DJ: Pediatric out-patient anesthesia. Anesthesiology 43:268-276, 1975 3. Anderson R: Pain as a major cause of post-operative nausea. Can Anaesth Soc J 23:366-369, 1976 4. Goodman LS, Gilman A: Pharmacological Basis of Therapeutics (ed 5). London, MacMillan, 1975 5. Garfield JM: Clinical pharmacology of local anesthetics used in out-patient procedures. Int Anesth Clin 14(2):51-62, 1976 6. Makuria T, Alexander-Williams J, Keighley MRB: Comparison between general and local anaesthesia for repair of groin hernias. Ann R Coil Surg Engl 61:291-294, 1979 7. Dhuner KG: Clinical experience with marcaine (LAC 43), A new local anaesthetic. ACTA Anesthesiol Scand [Suppl] 23:395401, 1966 8. Bellis C J: Immediate unrestricted activity after operation with particular reference to 11,272 inguinal herniorrhaphies using local anesthesia. Int Surg 55:256 264, 1971

9. Goresky G, Steward D J: Rectal methohexitone for induction of anaesthesia in children. Can Anaesth Soc J 26:213-215, 1979 10. Moore DC: Regional Block (ed 4). Springfield, Illinois, Charles C Thomas, 1975 11. Chang FC, Farha G J: Inguinal herniorrhaphy under local anesthesia. A prospective study of 100 consecutive patients with emphasis on perioperative morbidity and patient acceptance. Arch Surg 112:1069-1071, 1977 12. Moore DC, Mather LE, Bridenbaugh LD, et al: Arterial and venous plasma levels or bupivacaine following peripheral nerve blocks. Anesth Analg (Cleve) 55:763-768, 1976 13. Davenport HT, Chah CP, Robinson GC: Day surgery for children. Can Med Assoc J 105:498 500, 1971 14. Steward DJ: Experiences with an out-patient anesthesia service for children. Anesth Analg (Cleve) 52:877-880, 1973