1 Urology Journal UNRC/IUA Vol. 1, 1-4 Winter 2004 Printed in IRAN INTRODUCTION Pain relieving is regarded as one of the basic issues in pediatric anesthesia during the opera- tion and postoperatively. Pain is one of the major factors of children's agitation immediately after surgery, a matter which is particularly seen in infants and little children who are unable to com- municate properly and do not receive an appro- priate dosage of analgesic drugs.(1) Postoperatively, pain would be followed by some physiologic complications manifested in human body systems and organizations. Pain, under the age of five could affect physical and mental sta- tus and even might associate with a high level of somatization.(2) Acetaminophen has an active metabolite known as phenacetin that provides analgesic and antipyretic effects. The mechanism of action is not well known. The analgesic effect of Acetaminophen may be due to its fair inhibition of prostaglandin in CNS.(3) This drug has no anti-inflammatory effects, and heightening pain threshold is considered as its analgesic mechanism.(3) Its normal dosage is 30-40 mg/kg used in divided dosages but in chil- dren under 12 years old is 1.5 gr/ m2/day. Hypersensitivity to this medication is known as its contradiction. In case of rectal bleeding, the drug should not be administered. The use of narcotics, regional anesthetics, anal- gesics such as NSAIDS, and probably non-phar- maceutical ways are considered as pain relieving methods during and after surgery.(4) Since even one dose of narcotics could increase postopera- tive vomiting and may followed by some compli- cations such as sedation and respiratory depres- sion, it is necessary to avoid prescription of even one dose of narcotics.(5) In addition to their limited effect in controlling A Comparison between Acetaminophen Suppository and Caudal Anesthesia in Relieving Pain after Pediatric Surgery RAZAVI SS*, SHAEGHI S, SHIVA H, MO'MENZADEH S Department of Anaesthesia, Mofeed Children Hospital, Shaheed Beheshti University of Medical Sciences, Tehran, Iran ABSTRACT Purpose: Our aim was to provide a simple, non-invasive, low cost, and practical method to be used by nurses and technicians in a low hazardous, safe, and painless- ness anesthesia. Materials and Methods: In a prospective blind clinical trial 40 children between 4 and 6 months who were candidated for subumbilical elective surgeries were recruit- ed. They were randomly divided into two groups. Bupivacain 0.25% was prescribed in the control group according to Armitage formula (0.5- 1 ml/kg); while, supp. Acetaminophen was administered in the subject group by a dosage of 30-40 mg/kg. Results: There was no statistically significant difference in the pain score of the two groups within 2 hours postoperatively, but higher pain score was reported in sub- ject group during the third and forth hours. Conclusion: Caudal anesthesia with bupivacaine has better painless period postop- eratively. KEY WORDS: acetaminophen suppository, caudal anesthesia, pediatric surgery Accepted for publication pain, NSAIDS have their own specific complica- tions such as GI bleeding and exacerbation of asthmatic crises. Among regional approaches, painlessness by caudal anesthesia is regarded as the most com- mon method in pediatric anesthesia, which is mostly applied in circumcision, hypospadiasis, club foot, herniorrhaphy, urogenital, and anal surgeries, and also generally subumbilical opera- tions.(6) Despite its advantages, caudal method has sev- eral disadvantages including: - An experienced specialist is needed to per- form this method. Nonetheless, approximate- ly 10% of cases ended in failure.(6) - This method cannot be practical in the case of regional infection.(1) - Painlessness would be obtained just for a lim- ited time. - It is impractical in major malformations of sacrum, myelomeningocele and meningitis.(6) - Among local anesthesia methods, toxicity risk of local drugs in this method (preceded by intercostal method) would be higher than other methods which is due to intravenous or intraosseous injections.(6) - Intrathecal injection can also be done but hypotension can also occur in less than 8- year-old children.(6) - Postoperative urination might be delayed and vomiting is reported in 30% of cases.(6) Accordingly, there has not been any ideal method for children painlessness during and after anesthesia. In this study, we attempted to find a simple and practical method to be used by nurses and technicians in a low cost, less haz- ardous, and safe anesthesia with little pain. METERIALS AND METHODS Forty children between 6 month and 4 years who were candidated for subumbilical elective operations with ASA class I and II were includ- ed in this blind clinical trial regardless of sex. Those with CNS disorders, excessive hemor- rhage, and tachycardia during the surgery and those who received narcotics postoperatively were excluded from the study. Patients were connected to ECG monitoring device and pulse oxymeter for the detection of probable hypoxia, arrhythmia due to intravascu- lar injection of Bupivacaine, and tachycardia caused by pain, which indicates the failure of procedure. Precordial stethoscope was also fixed for them. All patients were given similar premedication and oral Midazolam (0.3 mgr/kg) and Atropine (0.02 mgr/kg) were prescribed 30 minutes before surgery. All patients were anesthetized deeply by Sodium Thiopental (6mg/kg), Halothane with a Maximum concentration of 2%, and N2O gas 50% to 70% without muscle relaxants. Laryngeal mask airway was applied appropri- ately to their age and patients were randomly selected using random table assignment. Supp. Acetaminophen 40 mg/kg was given in the subject group and caudal anesthesia in later- al position was applied to the other. A maximum of 20 cc of Bupivocaine 0.25% was used according to Armitage formula 0.5-1 ml/Kg to induce blockage to high lumbar- high sacral areas (Single-shot caudal block). Niddle number 23 gauge was used in all the cases accurately. Patients' breathing was automatic, although, they were given assisted ventilation occasionally. Post- operatively, patients' pain score was evalu- ated every one hour for four hours by a trained nurse who was unaware of the used method of anesthesia and painlessness. FLCAC pain score was used to estimate the pain (table 1). 2 TABLE 1. Pain Score (FLCAC) Pain score Giterion O I 2 F(face) No special mood or laughing could be seen Sometimes he frowns and pulls himself back He frowns repeatedly and press his mandibles on each other L(Legs) Normal position of legs in rest He is unease and agitated and he contracts his legs a little He kicks his legs & moves up and down C( Crying) No Crying (conscious, sleepy) He moans or cry's and sometimes sufferers from pain He always moans & cry's or screams A (Activity) He sleeps calmly with normal activity and moves with ease He moves toward back & forth , right & left & feels uncomforted His limbs are bent & his muscles are contracted with sudden movement C(Consol ability) He is calm & comfort He becomes calm by embracing and pampering him It is difficult to console him & make him comfort RESULTS Six girls and 14 boys were included in the sub- ject (Acetaminophen) group and 6 girls and 14 boys comprised the control (caudal) group (fig.1). The mean ages were 19 months and 21 months in subjects and control groups respectively. At the first hour the maximum level of pain score in both groups did not exceed 4. Four patients had 2-4 score in the case group; while, 3 cases felt 2-4 score in the control group. Eighty two percent of patients had no remarkable pain at the first hour but 18% of them felt little pain that eased off (fig. 3, 4). At the second hour a significant number of patients had <2 pain scores in both groups and there was no statistical difference between them and one patient in the subject group had a score in the range of 2-4 (fig. 2, 4). Fifteen percent in the case group and 5% in the control group had 2-4 pain scores in the third hour postoperatively (fig. 3). As indicated in table 2, patients gained a cumulative score of 16 in the subject group and 3 in the control group from which a significant statistical difference between the two groups could be notified that might be due to the decrease of plasma level of Acetaminophen regarding its half-life. Thirty percent of subject group had 2-4 pain score and 5% felt >4 pain score, while, 90% of control group had <2 score (table 2). Total score of 20 studied patients was 28 in the case group and 8 in the control group, which indicates a significant discrepancy between the two groups and emphasizes that decreasing plas- ma level of Acetaminophen has resulted in high- er pain scores. DISCUSSION In accordance with previous studies, Bupivocaine 0.25% compared to its lower concen- trations provides a better painlessness and is of no risk in subumbilical surgeries; hence, the same concentration was used in this study.(7) Earlier studies show that prophylactic Acetaminophen could decrease pain in surgical procedures mild to moderately.(10, 11) In this study, the same finding was observed too. In a study comparing Diclofenac to Bupivocaine, pain incidence and intensity in Diclofenac group were higher than Bupivocaine group at the first hours; however, in this study no difference was noted at first hours, but pain 3 FIG. 1. The frequency of genders in the subject and control groups 0 2 4 6 8 10 12 14 16 Control Study N u m b e r Male Female FIG. 2. The frequency of <2 pain scores at the first to the fourth postoperative hour in the sub- ject and the control group 0 5 10 15 20 25 1st Hour 2nd Hour 3rd Hour 4th Hour N u m b e r Control Study TABLE 2. Pain score table of the subject and con- trol groups at the four postoperative hours Fourth hour Third hour Second hour First hour Control group Fourth hour Third hour Second hour First hour Subject group 0 5 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 4 0 0 0 4 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 4 1 5 0 0 0 0 3 0 0 0 1 0 4 3 0 0 4 3 0 3 1 2 1 0 0 0 3 0 3 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 1 0 3 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 4 0 4 0 0 3 4 0 0 0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0.4 0.15 0 0.7 1.4 0.75 0.25 0.8 Mean X 1.273 0.67 0 1.04 1.82 1.07 0.695 1.58 Standard Deviation 8 3 0 10 28 16 5 16 Total incidence and intensity increased more in case group later on.(8) Regarding that in an investigation painlessness duration in surgical operations with caudal anes- thesia exactly before the beginning of short peri- od surgeries did not differ, in this study caudal anesthesia was performed before the beginning of surgery in this study. Regarding the results obtained from statistical analysis of both groups and their pain score com- parison at the first and the fourth hours, and also considering the resultant P value, we can conclude that there was statistically no signifi- cant difference in the pain score of both groups at the first and the second hours. Moreover, it can be hypothesized that there is no difference between using caudal anesthesia and supp. Acetaminophen concerning postoperative pain intensity at the first and the second hours. However, considering P value in the comparison of both groups' pain score at the third and the fourth hours, it can be concluded that pain level in the subject group was higher than the one in the control group. CONCLUSION Generally, it can be concluded that the children who received caudal Marcaine for postoperative painlessness, experienced a better and longer painlessness; yet, if caudal anesthesia is impossi- ble (due to anatomic problems of sacrum, local infection, medication lackness, etc.), at least a supp. of Acetaminophen could be helpful in pain relieving at the first few postoperative hours. REFERENCES 1. Davis, Moyotoma. Smiths' Anesthesia for Infant and children. 3rd ed. W. B. Saunders; 1996. p. 316. 2. Sumner, Edward, Hatch DJ. Pediatric Anesthesia. 4th ed. Churchill Livingstone; 1999. p. 148, 268. 3. KATZONG BG. Basics of clinical pharmacolo- gy. 5th ed. p. 506. 4. Houck CS, Berde CB, Anand KJS. Pediatric pain management. In: Gregory, editor. Pediatric anesthesia. New York: Churchill Livingstone;1994. p. 743. 5. Weinstein MS, Nicolas SC, Schreimner MS. A single dose of Morphine increases the inci- dence of vomiting. Anesthesiology 1994; 81: 572. 6. Miller, Roland. Anesthesia. 5th ed. Churchill Livingstone; 2000. p. 1560-1561. 7. Grunter JB, Dann CM, Bennie JB, et al. Department of Anesthesiology. Washington university school medicine Medline; 1991. 8. Moors MA, Wandless JG, Fell D. Comparison of caudal block using bopivacaine and diclofenac supp in children for Ilioingoinal Herniotomy. Department of Anesthesia, Leicester Royal infirmity 1999 Feb. 9. Rice LG, Pudimat MA, Hannallah RS. Management of post operative pain in chil- dren with caudal anesthesia. Department of Anesthesiology, children's National Medical Center, Washington, D.C 1990 May. 4 FIG. 3. The frequency of 2-4 pain scores at the first to the fourth postoperative hour in the sub- ject and the control group FIG. 4. The frequency of >4 pain scores at the first to the fourth postoperative hour in the sub- ject and the control group 0 2 4 6 8 10 12 14 16 1st Hour 2nd Hour 3rd Hour 4th Hour N u m b e r Control Study 0 2 4 6 8 10 12 14 16 1st Hour 2nd Hour 3rd Hour 4th Hour N u m b e r Control Study 10. Romej M, Veepel-Lewis T, Reynold PI. Effect of preemptive Acetaminophen on postopera- tive pain score and oral intake in pediatric tonsillectomy patient. AANA Journal 11996 Dec; 64 (6): 535-540. 11. Postoperative pain relief in children with Acetaminophen comparison with Thramadol. European Journal of Anesthesiology 1999 July; 16 (7): 473-478. 5