Postoperative analgesia in children who have genito-urinary surgery A comparison between caudal buprenorphine and bupivacaine

A study conducted on 40 children, aged 1-11 years, who had genito-urinary surgery compared the quality and duration of analgesia after caudal blocks in two groups of patients. Group 1 (n = 20) received caudal bupivacaine 0.25% and group 2 (n = 20) caudal buprenorphine 4 micrograms/kg; each received 0.5 ml/kg body weight. Patients were operated on under general anaesthesia. Postoperative behaviour and severity of pain were measured on a 3-point scale. The results indicate that caudal buprenorphine provides excellent postoperative analgesia in children comparable to caudal bupivacaine in the early postoperative period. Buprenorphine proved better in the late postoperative period. Analgesia lasted from 20 hours to more than 24 hours after caudal buprenorphine with fewer side effects.     

Paediatric postoperative analgesia

Fifty children who underwent day case herniotomy received either a caudal injection of 1 ml/kg bupivacaine 0.25% or infiltration of the wound edges at the end of surgery with 0.5 ml/kg bupivacaine 0.25%, allocated at random. Postoperative pain and demeanour were assessed initially by an observer and later by use of a parental questionnaire. Wound infiltration of local anaesthetic solution provided analgesia which was comparable to that associated with caudal block, and the incidence of side effects was similar in the two groups. Wound infiltration of local anaesthetic offers a simple, safe alternative to caudal block for provision of postoperative analgesia in this group of patients.     

Postoperative pain relief in children

Two hundred and fifty children undergoing herniotomy or orchidopexy under general anaesthesia were randomly allocated to receive pre-operatively either diclofenac sodium 1 mg.kg^-1 given intramuscularly or a caudal injection of bupivacaine 0.25% 1 ml.kg^-1 with or without adrenaline or no analgesia. Plasma diclofenac and beta-endorphin concentrations were determined in eight and 21 patients respectively. Postoperative pain was assessed by ward nurses who were blinded to the group allocation. Comparison with the control group showed diclofenac to be an effective analgesic. Caudal bupivacaine provided more pain-free children during the early postoperative hours, but later the need for pethidine as rescue analgesic was lower among the children who had received intramuscular diclofenac. Caudal analgesia abolished the stress-induced increase in plasma beta-endorphin level which was found in the children given diclofenac and in those who served as controls. Total plasma clearance of intramuscular diclofenac sodium appears to be higher in children than in adults. A single intramuscular dose of diclofenac significantly reduces the need for an opioid analgesic in children after inguinal herniotomy or orchidopexy, and owing to its long duration of action, it offers an alternative or complementary method of pain relief to caudal analgesia.     

The optimal dose of ketamine for caudal epidural blockade in children

Sixty boys aged up to 9 years undergoing orchidopexy were randomly allocated to receive one of three solutions for caudal epidural injection: group A received 1 ml. kg⁻¹ of 0.25% bupivacaine with 0.25 mg. kg⁻¹of preservative-free ketamine, group B received 1 ml. kg⁻¹ of 0.25% bupivacaine with ketamine 0.5mg. kg⁻¹ and group C received 1 ml. kg⁻¹ of 0.25% bupivacaine with 1 mg. kg⁻¹ of ketamine. Postoperative pain was assessed by means of a modified Objective Pain Score and analgesia was administered if this score exceeded four. The median duration of caudal analgesia was 7.9h in group A, 11 h in group B and 16.5 h in group C. There were no differences between the groups in the incidence of motor block, urinary retention, postoperative vomiting or postoperative sedation. Group C had a significantly higher incidence of behavioural side effects, including slightly odd behaviour, vacant stares and abnormal effect than groups A and B.     

Caudal bupivacaine-tramadol combination for postoperative analgesia in pediatric herniorrhaphy

BACKGROUND: Administration of bupivacaine caudally has been used for postoperative analgesia after urogenital, rectal and lower abdominal surgery in children. Caudal opioids may offer analgesic advantages over bupivacaine alone but have been associated with side effects such as respiratory depression. Tramadol is an analgesic assumed to lack a respiratory depressant effect and has been shown to provide effective, long-lasting analgesia after epidural administration in adults and children. The aim of this study was to determine whether the addition of tramadol to bupivacaine caudally prolongs the duration of analgesia compared with bupivacaine alone, with respect to side effects, and whether caudal tramadol alone provides satisfactory analgesia. METHODS: Sixty boys, aged 12-84 months, undergoing unilateral herniorrhaphy, were allocated randomly to three groups. Children in group B received 0.25% plain bupivacaine 1 ml kg(-1), group BT received an identical local anesthetic dose mixed with tramadol 1.5 mg kg(-1) and group T received caudal tramadol 1.5 mg kg(-1) in 0.9% sodium chloride in the same total volume (1 ml kg(-1)). Pain and demeanour assessments were made 1, 2, 3, 4, 6, 12 and 24 h after recovery from anesthesia with reference to a three-point scale. RESULTS: Analgesia time (time between caudal injection and first administration of analgesic) in group BT (13.5+/-2.2 h) was significantly longer than in the other two groups (P<0.05). In group T, more patients required additional analgesia after surgery than in the other two groups (P<0.05). Pain scores in the three groups were similar up to 4 h after operation but the mean score in group T was higher than groups B and BT 4 and 6 h after operation (P<0.05). Significantly more patients who had received caudal bupivacaine alone or with tramadol had lower pain and demeanour scores during the first 24 h after operation compared with those in the tramadol group. CONCLUSION: Caudal administration of bupivacaine with the addition of tramadol resulted in superior analgesia with a longer period without demand for additional analgesics compared with caudal bupivacaine and tramadol alone without an increase of side effects.     

Postoperative analgesia using caudal morphine in pediatric surgery: randomized double-blind study compared with bupivacaine

Morphine and bupivacaine have been administered caudal via to 28 children between 2 and 12 years old for the postoperative pain treatment. All of them were submitted to general anesthesia and randomly divided into 3 groups depending on the drug administered caudal via. a) Morphine group (n = 10): morphine chlorhydrate 50 micrograms/kg (0.5 ml/kg of morphine solution 100 micrograms/ml). b) Bupivacaine group (n = 10): bupivacaine 0.5%, 2.5 mg/kg. c) Control group (n = 8): no drug administered. Pain evaluation was made on the basis of physiological and clinical data. In the morphine group, the postoperative time until analgesia was required 20 +/- 5 hours and analgesia has been significantly better (p less than 0.001) than bupivacaine and control group. The number of analgesic drug needed during the postoperative 24 first hours was also less in morphine group. No differences on postoperative complications were seen among the 3 groups and no case of respiratory depression was observed. It is concluded that epiduro-caudal morphine provides effective and prolonged analgesia and can be safely used for postoperative pain treatment in pediatric urologic surgery. However, we believe, that larger series of patients will provide better information of its efficacy and other side effects.     

Preemptive analgesia for postoperative pain relief in lumbosacral spine surgeries: a randomized controlled trial.

BACKGROUND CONTEXT: Administration of analgesic medication, before the actual onset of painful stimulus, is more effective than that after the onset of painful stimulus. This is the principle of preemptive analgesia. Although it is often considered superior to other forms of analgesia, its role in postoperative pain relief after lumbosacral spinal surgery has not been fully investigated. PURPOSE: To analyze the efficacy of preemptive analgesia with a single caudal epidural injection for patients undergoing surgeries on the lumbosacral spine by the posterior approach. STUDY DESIGN/SETTING: Randomized, double-blinded and controlled clinical trial. PATIENT SAMPLE: Eighty-two patients who underwent discectomy in the lumbosacral spine by the posterior approach, with or without instrumentation, were randomized to the control group (n=40) and to the study group (n=42). METHODS: Patients in control group received a single caudal epidural injection of 20 ml of normal saline. Patients in study group received a single caudal epidural injection of 20 ml containing bupivacaine and tramadol as the active agents. The time interval between this injection and the surgical incision was never less than 20 minutes in either of the groups. This facilitated enough time for the drug to get fixed to the nerve roots, leading to effective preemptive analgesia. OUTCOME MEASURES: Patients were monitored for postoperative pain immediately after surgery when they had completely recovered and regained consciousness from general anesthesia, and subsequently 4, 8, 12 and 24 hours thereafter. Pain was quantified using the visual analog scale (VAS) and the verbal rating scale (VRS). The time at which supplemental analgesic medication was first demanded in the postoperative period by the patient was also noted. RESULTS: The two groups were comparable for age, sex, body weight and the type of surgery they underwent. Because the data did not have a normal Gaussian distribution, the one-tailed Mann-Whitney test, being a nonparametric test, was adopted for statistical analysis. Accordingly, VAS and VRS values at all time intervals were significantly lower (p<.0001) in the study group as compared with the control group. This indicated significantly better pain relief in the study group. There was also a significant delay (p=.0041) in the first demand for supplemental analgesic medication in the postoperative period in the study group. No complication specific to the procedure was noted except for the development of postoperative urinary retention, which was transient and appropriately managed with urinary catheterization. CONCLUSIONS: Preemptive analgesia with a single caudal epidural injection of bupivacaine and tramadol is a safe, simple and effective method for postoperative pain relief.     

Caudal morphine for postoperative analgesia in children: a comparison with caudal bupivacaine and intravenous morphine

We compared the efficacy, duration, and side effects of preservative-free morphine injected into the caudal space in children, with caudal bupivacaine and with intravenous morphine administration for relief of postoperative pain. Forty-six children, ages 1-16 yr, were randomly assigned to receive intravenous morphine (control group), caudal bupivacaine (0.25%, 1 ml/kg), or caudal morphine (0.5 mg/ml, 0.1 mg/kg). In half the patients given caudal morphine, the morphine was mixed with a dose of lidocaine adequate to produce sacral analgesia, to confirm correct caudal injection of the morphine. Caudal injections were performed at the end of surgery. Time until the first required postoperative intravenous morphine dose was recorded for each patient. The duration of analgesia was significantly greater with caudal morphine (median 12 hr, P less than 0.02) than with caudal bupivacaine (median 5 hr), and both were greater than with intravenous morphine in control patients (median 45 min). Urinary retention, pruritis, and nausea appeared with slightly greater frequency in the caudal morphine group, but no delayed respiratory depression occurred. Caudal morphine (0.5 mg/ml, 0.1 mg/kg) provided 8-24 hr of analgesia in children without a significantly greater incidence of side effects than caudal bupivacaine or intravenous morphine.     

Caudal neostigmine for postoperative analgesia in paediatric surgery

BACKGROUND: This study was conducted to evaluate analgesia and side-effects of caudal neostigmine coadministered with bupivacaine in paediatric surgery. METHODS: We studied children, aged 1-5 years, undergoing elective surgery (inguinal hernia and hypospadias). After standard induction of anaesthesia, caudal anaesthesia was performed. Group 1 received 0.25% bupivacaine 0.5 ml.kg-1 and Group 2 received 0.25% bupivacaine 0.5 ml x kg-1 with 1 microg x kg-1 neostigmine via the caudal route. Heart rate, mean arterial pressure, peripheral oxygen saturation were recorded before induction, after induction but before caudal anaesthesia, and then every 5 min after caudal anaesthesia. Haemodynamic, Toddler, Preschooler, Postoperative Pain Scale (TPPPS) pain score and sedation score values were recorded 30 min after extubation and at hours 2, 4, 6, 12 and 24. A pain score >3/10 resulted in administration of rectal paracetamol. The duration of postoperative analgesia was defined as the time between caudal drug injection and the first rectal paracetamol administration. RESULTS: There were no differences between the groups in demographic and haemodynamic date, duration of surgery and anaesthesia, time to extubation or sedation scores. The duration of postoperative pain relief did not differ between the two groups; 15.40 +/- 10.97 h for group 1 vs. 15.45 +/- 10.99 h for group 2 (P > 0.05). The incidence of nausea (three patients in group 2 and one patient in group 1) was not statistically significant. No other side-effects were seen. CONCLUSIONS: We found that a single caudal injection of 1 microg x kg-1 neostigmine mixed with bupivacaine offers no significant advantage over bupivacaine alone for postoperative pain relief in children undergoing genitourinary surgery.     

Dose response study of subarachnoid diamorphine for analgesia after elective caesarean section

Subarachnoid diamorphine provides excellent analgesia after elective caesarean section but the optimum dose is still uncertain. We therefore investigated the effects of three regimens of subarachnoid diamorphine. Forty parturients were assigned to one of four groups. A control group received no diamorphine in their subarachnoid bupivacaine and three study groups received 0.1 mg, 0.2 mg or 0.3 mg diamorphine added to 12.5 mg hyperbaric bupivacaine 0.5% in a semi-blind randomised design study. All women received a 100 mg diclofenac suppository at the end of the caesarean section and were provided with morphine patient controlled analgesia (PCA) postoperatively. The patients were assessed for pain, morphine usage and side-effects at 2, 4, 8 and 24 h after the subarachnoid injection. Postoperative visual analogue scores for pain and PCA morphine consumption were significantly lower, and mean time to first use of morphine was significantly longer in the 0.3 mg diamorphine group. The mean (SD) dose of PCA morphine used over 24 h was 39.4 (14.7), 25.6 (16.5), 21.6 (15.9) and 3.1 (3.6) mg, and mean time to first use of morphine was 1.6 (0.5), 3.0 (1.4), 3.4 (2.4) and 14.1 (9.4) h, in the 0, 0.1 mg, 0.2 mg and 0.3 mg groups respectively. Side-effects of pruritus, nausea and vomiting were dependent on the dose of spinal diamorphine but did not require treatment in any patients. We conclude that 0.3 mg subarachnoid diamorphine provides significantly better postoperative pain relief than the smaller doses with an acceptable increase in side-effects.     

EXTRADURAL DIAMORPHINE WITH ADRENALINE IN LABOUR: COMPARISON WITH DIAMORPHINE AND BUPIVACAINE

In a randomized double-blind study of 51 primigravida, we haveexamined the relative efficacies of bupivacaine, diamorphineor diamorphine with adrenaline given by the extradural routefor relief of pain during labour. Group 1 (n = 18) receiveddiamorphine 5 mg in 0.9% sodium chloride 8 ml; group 2 (n =19) received diamorphine 5 mg in 0.9% sodium chloride 8 ml with1: 200 000 adrenaline; group 3 (n = 14) received 0.375% bupivacaine8 ml. All patients received 0.375% bupivacaine 8 ml as a supplementafter the initial analgesia had subsided. Patients in all groupshad satisfactory and comparable analgesia 20 min after the initialinjection. However, after 60 min and up to 8 h, analgesia wassuperior in group 2 as assessed by linear analogue pain scores,with statistical significance at 4, 6 and 8 h. Groups 1 and2 required bupivacaine supplements less frequently than group3 (P < 0.001). There were no serious adverse effects in anygroup, but pruritus was a feature in the diamorphine groups.Diamorphine 5 mg may be used as an alternative to bupivacaine0.375% 8 ml in the first stage of labour and provides a longerduration of action. The addition of adrenaline 1: 200 000 appearsto augment both the quality and duration of analgesia.     

Paediatric postoperative analgesia A comparison of rectal diclofenac with caudal bupivacaine after inguinal herniotomy

Forty-three children for day case inguinal herniotomy under general anaesthesia were assigned randomly to receive either 1 ml/kg caudal bupivacaine 0.25% or rectal diclofenac 0.25 mg/kg intra-operatively to provide postoperative analgesia. Pain and demeanour were assessed by an observer in the early postoperative period after operation and by questionnaire for the parents over the first 24 hours. Caudal bupivacaine provided more pain-free patients at first but later the incidence of pain was similar in the two treatment groups. Rectal diclofenac is a useful alternative to caudal blockade in this group of patients.     

Comparison of caudal bupivacaine and diamorphine with caudal bupivacaine alone for repair of hypospadias

Forty-five boys undergoing repair of hypospadias were allocated randomly to one of two groups. After induction of anaesthesia, 22 patients received 0.25% caudal bupivacaine 0.5 ml kg-1 and diamorphine 30 micrograms kg-1 and the remaining 23 patients received 0.25% caudal bupivacaine 0.5 ml kg-1 alone. Pain scores (Children's Hospital of Eastern Ontario Pain Scale), sedation scores, ventilatory frequency, analgesic requirements and associated side effects were recorded for the first 24 h after operation. The two groups were indistinguishable in age, weight and duration of surgery. There was a statistically significant reduction in early pain scores. There was also a statistically significant increase in the time to first passage of urine in those boys in the diamorphine group who were not catheterized during operation.      

Double-blind randomized controlled trial of caudal versus intravenous S(+)-ketamine for supplementation of caudal analgesia in children

Background. The postoperative analgesic efficacy of S(+)-ketamineafter caudal or i.v. administration following sub-umbilicalsurgery in children was studied to investigate its principalsite of analgesic action. Methods. Sixty children undergoing caudal block during generalanaesthesia for hernia repair or orchidopexy were prospectivelyrandomized to one of three groups: the bupivicaine group receivedplain bupivacaine 0.25% 1 ml kg^–1; the caudal ketaminegroup received caudal plain bupivacaine 0.25% 1 ml kg^–1with S(+)-ketamine 0.5 mg kg^–1; the i.v. ketamine groupreceived caudal plain bupivacaine 0.25% 1 ml kg^–1 plusS(+)-ketamine 0.5 mg kg^–1 i.v.. Postoperative measurementsincluded analgesic requirements and modified objective painscore for the first 24 h. Results. The median time to first analgesia was significantlylonger in the caudal ketamine group (10 h) than in the i.v.ketamine (4.63 h) or bupivacaine (4.75 h) groups (P=0.01). Significantlyfewer doses of analgesia were required over the first postoperative24 h by subjects in the caudal ketamine group (median 1) comparedwith the i.v. ketamine (median 2) or bupivacaine (median 2.5)groups (P<0.05). There was no difference between the groupsin the incidence of postoperative nausea and vomiting or psychomotorreactions. Conclusions. We have demonstrated that the addition of caudalS(+)-ketamine to bupivacaine prolongs the duration of postoperativeanalgesia. However, the same dose of i.v. S(+)-ketamine combinedwith a plain bupivacaine caudal provides no better analgesiathan caudal bupivacaine alone, indicating that the principalanalgesic effect of caudal S(+)-ketamine results from a localneuroaxial rather than a systemic effect. Br J Anaesth 2004; 92: 344–7     

Caudal blockade for postoperative analgesia: a useful adjunct to intramuscular opiates following emergency lower leg orthopaedic surgery.

The efficacy of a single caudal epidural injection of bupivacaine 20 ml 0.5% following emergency orthopaedic surgery to the lower leg and ankle was investigated. Forty adult patients were studied, randomised to either the caudal or control group. The mean 24 hour postoperative papaveretum consumption was significantly reduced in the caudal group. Analogue pain scores as assessed in a double-blind manner were also significantly reduced in this group. The duration of analgesia after caudal blockade was approximately eight hours as estimated by the average time to the first dose of papaveretum. Our study demonstrates that caudal blockade represents an effective adjunct to intramuscular opiates following this type of surgery.     

Comparison of the effects of adrenaline, clonidine and ketamine on the duration of caudal analgesia produced by bupivacaine in children

Sixty boys, aged 1-10 yr, undergoing orchidopexy were allocated randomly to receive one of three solutions for caudal extradural injection. Group A received 0.25% bupivacaine 1 ml kg-1 with adrenaline 5 micrograms ml-1 (1/200,000), group C received 0.25% bupivacaine 1 ml kg-1 with clonidine 2 micrograms kg-1 and group K received 0.25% bupivacaine 1 ml kg-1 with ketamine 0.5 mg kg-1. Postoperative pain was assessed using a modified objective pain score and analgesia was administered if this score exceeded 4. The median duration of caudal analgesia was 12.5 h in group K compared with 5.8 h in group C (P < 0.05) and 3.2 h in group A (P < 0.01). There were no differences between the groups in the incidence of motor block, urinary retention or postoperative sedation.      

Caudal neostigmine,bupivacaine, and their combination for postoperative pain management after hypospadias surgery in children

In a randomized, double-blinded study, we examined the analgesic efficacy of caudal neostigmine, bupivacaine, or a mixture of both drugs in 60 children. After the induction of general anesthesia, children were allocated randomly into three groups (n = 20) to receive a caudal injection of either 0.25% bupivacaine 1 mL/kg, with or without neostigmine 2 micro g/kg, or neostigmine 2 micro g/kg in normal saline 1 mL/kg. Intraoperatively, children receiving caudal bupivacaine or a bupivacaine/neostigmine mixture maintained hemodynamic stability, required less inhaled anesthetics, and had a shorter recovery time compared with the caudal neostigmine alone. Postoperatively, the caudal bupivacaine/neostigmine mixture resulted in superior analgesia compared with the other two groups. Recovery to first rescue analgesic times were (mean +/- SD) 22.8 +/- 2.9 h, 8.1 +/- 5.9 h, and 5.2 +/- 2.1 h in the bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.001). In addition, the bupivacaine and neostigmine groups received more doses of paracetamol than the bupivacaine/neostigmine group to maintain adequate analgesia in the first 24 postoperative h. Postoperative vomiting occurred in 25%, 10%, and 30% in the caudal bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.01). We conclude that caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. IMPLICATIONS: Caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. Co-administration of the two drugs is associated with extended postoperative analgesia and reduced need for supplementary analgesics.     

Epidural analgesia with bupivacaine reduces postoperative paralytic ileus after hysterectomy

This study was undertaken to compare the effects of postoperative bupivacaine epidural analgesia with those of intermittent injections of ketobemidone (a synthetic opioid) on postoperative bowel motility in patients who had had hysterectomies. The epidural group (N = 20) received continuous epidural anesthesia with bupivacaine postoperatively for 26-30 hours and the control group (N = 20) received intermittent injections of ketobemidone for postoperative pain relief. Postoperative bowel movements and propulsive colonic motility were estimated from the first passage of flatus and feces and by following radiopaque markers by serial abdominal radiographs. In the epidural group, the times for first passing of flatus (31 +/- 22 hours; mean +/- SD) and feces (70 +/- 44 hours) were significantly shorter than in the control group (flatus 58 +/- 14 hours and feces 103 +/- 26 hours). The average position of the markers was significantly more distally in the epidural group immediately after operation and the markers continued to move forward during the first postoperative day. In the control group, the markers did not move during this period. The results demonstrate that postoperative bowel peristalsis returned earlier in the patients given epidural analgesia with bupivacaine for pain relief than in patients given a narcotic.     

Prospective to a randomized double-blind controlled trial to assess efficacy of double caudal analgesia in hypospadias repair

Background/Purpose: A prospective, randomised, double-blind, controlled trial to evaluate efficacy of double-caudal versus single-caudal injection for postoperative analgesia in hypospadias repair was performed. Methods: Between October 1998 and September 2000, 160 boys underwent distal hypospadias repair. The first 80 boys were analyzed prospectively for postoperative analgesia after double-caudal bupivacaine, which involves the administration of a second bupivacaine injection into the caudal extradural space at the end of surgery. Pain was assessed using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS). The study groups were: group 1, unstented Thiersch-Duplay urethroplasty (50); and group 2, stented Mathieu type repair (30). Results of this cohort formed the basis for a prospective, randomised, double-blind control trial comparing double-caudal against a single injection before operation. The further 80 patients were allocated randomly: group 3, single caudal injection of 1 mL kg^{[minus ]1} of 0.25% plain bupivacaine at the start of surgery with unstented Thiersh-Duplay repair (25); group 4, similar single caudal injection but stented Mattieu type operation (15); group 5, second caudal and at end of operation (0.5 mL kg^{[minus ]1} on each occasion) with unstented Thiersh-Duplay repair (25); and group 6, similar to group 5 but with stented Mattieu type repair (15). Results: Patient demographics (age and weight) and mean duration of operative time were similar for all groups. There was no significant difference in early pain scores at 0 to 2 hours with a good correlation coefficient (r = 0.88). At 4, 6, and 8 hours there was a significant difference in pain scores between double and single caudals (P [lt ] .05). There was a significant difference in mean duration of caudal analgesia and need for oral analgesia between single caudal 3.45 versus 7.85 hours for double caudal (P [lt ] .001). Mean duration of caudal analgesia and requirement for oral analgesia after single caudal in group 3 (unstented) was 3.5 versus 3.4 hours in group 4 (stented). In double caudals this lengthened to 9.4 hours in group 5 (unstented) versus 6.3 hours in group 6 (stented; P [lt ] .05). This also was significant when operation time was excluded. Conclusions: A prospective study of double caudal analgesia showed good postoperative pain control after hypospadias surgery. This was followed by a prospective, randomised, double-blind controlled trial that has confirmed that double caudal injection of bupivacaine prolonged the duration of pain relief after hypospadias repair. The second or top-up caudal did not increase the total dose but supplemented and prolonged postoperative analgesia.     

Efficacy of three doses of ketamine with bupivacaine for caudal analgesia in pediatric inguinal herniotomy

BACKGROUND AND OBJECTIVES: Ketamine administered systemically is a potent analgesic at subanesthetic plasma concentrations. Addition of ketamine to bupivacaine for caudal epidural block significantly prolongs the duration of postoperative analgesia. The purpose of this prospective, randomized double-blind study is to identify the optimal dose of ketamine that produces the maximum duration of caudal analgesia with minimal adverse effects as an adjuvant to bupivacaine for caudal epidural block. METHODS: Sixty children, aged 6 months to 10 years, undergoing inguinal herniotomy were allocated randomly to receive 1 of 3 solutions for caudal epidural block. Group 1 received 0.75 mL/kg of bupivacaine 0.25% with preservative-free ketamine 0.25 mg/kg, group 2 received 0.75 mL/kg of bupivacaine 0.25% with ketamine 0.5 mg/kg, and group 3 received 0.75 mL/kg of bupivacaine 0.25% with ketamine 1 mg/kg. Postoperative pain was assessed using the All India Institute of Medical Sciences pain discomfort scale. Rescue analgesia in the form of pethidine 1 mg/kg intramuscularly was administered when this score exceeded 4. RESULTS: The mean duration of caudal analgesia was 8.8 hours in group 1 compared with 22.1 hours in group 2 (P <.001) and 25.2 hours in group 3 (P <.001). Supplemental analgesia requirements with pethidine were significantly less in group 2 (4 subjects) and group 3 (no subject) when compared with group 1 (18 subjects). There were no differences between the groups in the incidence of motor blockade, urinary retention, emesis, or sedation. Group 3 had a significantly higher incidence of behavioral side effects such as odd behavior, agitation, or restlessness than groups 1 and 2. CONCLUSIONS: The optimal dose of ketamine in our study was 0.5 mg/kg added to 0.75 mL/kg bupivacaine 0.25% for caudal epidural block without an increase in side effects.