Comparison between epidural infusion of fentanyl/bupivacaine and morphine/bupivacaine after orthopaedic surgery

Purpose

To compare epidural infusions of bupivacaine-fentanyl and bupivacaine-morphine mixtures for postoperative pain relief after total hip replacement.

Methods

In a prospective, randomized, double-blind study, 30 ASA physical status I–II patients undergoing total hip replacement were studied. Anaesthesia was provided by combined general/epidural anaesthesia without epidural opioids. Postoperative epidural analgesia was by continuous infusion of bupivacaine 0.125% (4 ml·hr^?1) with either 0.05 mg·ml^?1 morphine (morphine, n = 15) or 0.005 mg·ml^?1 fentanyl (fentanyl, n = 15). Visual analogue pain scale (VAS), sedation (fourpoint scale), respiratory rate, pulse oximetry, rescue analgesics and supplemental oxygen were recorded by a blind observer at 1,3, 6, 9, 12 and 24 hr after surgery.

Results

No differences in pain relief, sedation, or non-respiratory side effects were observed between the two groups. Rescue analgesics were required in three patients in the fentanyl group (20%) and in two receiving morphine (13.3%) (P:NS). Two patients in the fentanyl group and three in the morphine group required oxygen due to SpO₂ < 90% (P:NS). Both opioid/bupivacaine mixtures decreased haemoglobin oxygen saturation compared with preoperative values. The mean ± SD SpO₂ values measured at 3,6, 12 and 24 hr were 94.4 ± 1, 92.6 ± 0.9, 92 ± 0.8, and 92.8 ± 1 in the morphine group, 95.3 ± 0.5, 95 ± 0.5, 94.6 ± 1.2, and 95.6 ± 1 in the fentanyl group (P < 0.05).

Conclusion

Continuous epidural infusion of bupivacaine-morphine or bupivacaine-fentanyl mixtures provided similar pain relief. Patients receiving morphine showed a more marked decrease in SpO₂ than those receiving fentanyl. However, the average SpO₂ remained > 90% in both groups.     

Epidural analgesia for labour and delivery: fentanyl or sufentanil?

Purpose

The highly lipid soluble opioids, fentanyl and sufentanil, are used in combination with local anaesthetics with/ without epinephrine to provide epidural analgesia during labour and delivery. Our aim was to determine whether either opioid was superior when used with low dose local anaesthetic.

Methods

In a double-blind study patients were randomized to two epidural infusion groups: Group I (n = 50) fentanyl 2 μg · ml^?1 with bupivacaine 0.015% and epinephrine 2 μg · ml^?1, Group II (n = 50) sufentanil 1 μg · ml^?1 with bupivacaine 0.015% and epinephrine 2 μg · ml^?1. Following a 20 ml bolus of the study solution an infusion was started at 10 ml · h^?1. To achieve analgesia patients could receive two boluses of 5 ml of the study solution and if analgesia was still inadequate, a further 5 ml bupivacaine 0.25% was used. Pain and overall satisfaction were assessed with a 10-point visual scale. Plasma samples obtained from the mother at the time the infusion was discontinued and from the umbilical cord vein at delivery were assayed to determine opioid concentration.

Results

Pain scores were greater for Group I than for Group II patients throughout the first and second stages of labour (P = 0.002). More patients in Group I (42%) requested a dose of bupivacaine 0.25% than in Group II (6%) (P < 0.0001) and the total dose of bupivacaine given to Group I patients was greater than that of Group II, 26.0 ± 22.0 mg vs. 13.4 ± 12.6 mg, P = 0.005. There were no differences with respect to first or second stage duration, incidence of side effects, infusion duration, outcome of labour or neonatal Apgar scores. There was no opioid accumulation in either maternal or foetal blood.

Conclusion

Epidural opioid infusion with very low dose bupivacaine (0.015%) achieved an overall high level of patient satisfaction in both groups without serious maternal or neonatal side effects. At the fentanyl-to-sufentanil ratio used here patients receiving sufentanil had lower pain scores and substantially fewer patients required bupivacaine rescue.     

Density determination of local anaesthetic opioid mixtures for spinal anaesthesia

Purpose

To measure the density of hyperbaric and isobaric local anaesthetics before and after addition of neuroaxial opioids to define a method for calculating any local anaesthetic/opioid mixture density based on individual component densities.

Methods

Density was determined using a volumetric pycnometer (25.0281 ± 0.0013 ml). The density of local anaesthetics (bupivacaine, lidocaine), opioids (fentanyl, morphine) and multiple anaesthetic/opioid mixtures were measured in quadruplicate and expressed in g·ml^?1, at 37°C (mean ± SD). Regression analysis was used to derive a formula for calculating the density of any anaesthetic/opioid mixture.

Results

Individual components had the following densities (g·ml^?1): bupivacaine 0.75%; 1.0252 ± 0.0001, lidocaine 5%; 1.0249 ± 0.0001, bupivacaine 0.5%; 0.9994 ± 0.0001, lidocaine 2%; 1.0000 ± 0.0001, 50μg·ml^?1 fentanyl; 0.9936 ± 0.0001, and 0.5 mg·ml^?1 morphine; 1.0001 ± 0.0001. Using regression analysis, linear relationships were demonstrated between density (D) of anaesthetic/opioid mixture and the proportion of anaesthetic in the mixture (fractional volume of anaesthetic) (r = 0.9999,P < 0.001). The following formula was derived; Density_Mixture = (D_{Local anaesthetic} ? D_Opioid) × Fractional Volume Anaesthetic + D_Opioid Comparison of calculated and measured densities for multiple clinically relevant anaesthetic/opioid mixtures showed a significant degree of correlation (r = 0.9996,P < 0.001).

Conclusion

Density of spinal anaesthetic/opioid mixtures can be calculated from the component densities and the proportion of anaesthetic in the mixture.     

Patient-controlled epidural analgesia in labour: varying bolus dose and lockout interval

This double-blind prospective study was designed to determine the best dose variables for patient-controlled epidural analgesia (PCEA) and to compare bolus-only PCEA with continuous infusion epidural analgesia (CIEA) during the first stage of labour. Five groups of parturients self-administered 0.125% bupivacaine with 1:400,000 epinephrine and fentanyl 2.5 μg·ml^?1 using PCA pumps programmed as follows: Group A, 2 ml bolus/10 min lockout interval (LI); Group B, 3 ml bolus/15 min LI; Group C, 4 ml bolus/20 min LI; Group D, 6 ml bolus/30 min LI; Group E, 8 ml·hr^?1 continuous infusion. Hourly assessments included: VAS scores for pain and satisfaction, sensory and motor block, bupivacaine and fentanyl consumption. Blood samples were collected at birth for maternal and fetal fentanyl concentrations. Data from 68 patients showed no differences among groups in pain relief or maternal satisfaction. Most patients received excellent analgesia and those requiring extra epidural supplements were evenly distributed across groups. There was higher consumption of bupivacaine and fentanyl in Group E than in any of the other four groups: bupivacaine mg·hr^?1, mean (SD), 9.4 (2.7) in Group E vs 5.2 (1.7) in Groups A-D inclusive (P<0.0001); fentanyl μg·hr^?1, 19.6 (4.6) in Group E vs 12.6 (7.5) in Groups A-D inclusive (P<0.05). Motor block was minimal, whereas sensory levels were higher at the 3- and 4-hour assessments in Groups D and E than in all other groups (P<0.05). Plasma fentanyl concentrations were <0.5 ng·ml^?1 in all samples and no sequelae from fentanyl were observed, apart from mild pruritus. Bolus-only PCEA is a safe and effective alternative to CIEA during the first stage of labour irrespective of the initial dose variables selected.     

Somatic paravertebral block decreases opioid requirements in children undergoing appendectomy

Purpose

Somatic paravertebral block (SPVB) appears to provide effective and prolonged nerve block in children; however, study of its use in this population is limited. We compared SPVB with no block in children undergoing appendectomy.

Methods

Thirty-six children aged 3-16 yr undergoing open appendectomy were involved in this prospective randomized controlled study. Anesthesia was induced with propofol and maintained with isoflurane in N₂O/oxygen. All subjects received fentanyl, acetaminophen and ketorolac during anesthesia. Group I (SPVB) subjects received a right SPVB at T₁₁, T₁₂, and L₁ using 0.2% ropivacaine 0.25 mL·kg^?1 with epinephrine 1:200,000 preoperatively. Group II (Control) had only bandaids applied to skin. Both groups were given morphine 0.05 mg·kg^?1 iv every 2 hr if pain scores reached 5/10 on a visual analogue scale. Acetaminophen was administered postoperatively every 6 hr to both groups. Time to first dose of morphine, total dose of morphine in 24 hr, and any adverse effects up to 24 hr after surgery were recorded.

Results

Group I (SPVB) subjects required significantly less morphine than Group II (Control) patients (0.12 ± 0.07 vs 0.34 ± 0.15 mg·kg^?1, respectively; P < 0.001), and time to their first dose was significantly longer (7.1 ± 4.4 vs 2.5 ± 1.6 hr, respectively; P < 0.001). Incidence of vomiting was 11% with Group I and 27% with Group II (P = 0.21). No other adverse effects were observed in either group.

Conclusions

In children undergoing appendectomy, SPVB provides better pain relief than no block and reduces opioid requirements. Side effects were not statistically different between groups.     

Postoperative analgesia with “3-in-1” femoral nerve block after prosthetic hip surgery

Purpose

To evaluate the efficacy of a single shot “3-in-1” femoral nerve block for prosthetic hip surgery in association with general anaesthesia on post-operative analgesia.

Methods

Forty patients, ASA 1 to 3, received sham block or “3-in-1” femoral nerve block, following Winnie’s landmarks with a nerve stimulator, and 40 ml bupivacaine 0.5% with epinephrine were injected after induction of anaesthesia. Vecuronium, 0.1 mg· kg^?1, was added after performing the block and anaesthesia was maintained with isoflurane, oxygen 40% and nitrous oxide 60%. Fentanyl, 1.5 μg· kg^?1, was administered before incision to all patients. Heart rate, blood pressure, fentanyl requirements and F_ETiso were measured throughout surgery. During the post-operative period, 75 mg diclofenacim and/or 0.1 mg· kg^?1 morphine sc were administered when pain score was > 3/10 and repeated when necessary. Pain scores at first analgesic intervention, at 24 hr and 48 hr as well as diclofenac and morphine requirements after surgery were recorded.

Results

There was no difference in anaesthetic requirements during surgery. The time from performance of sham or “3-in-1” femoral nerve block to the first analgesic intervention (261 ± 49 min versus 492 ± 40 min,P < 0.05) and time from extubation to the first analgesic intervention (61 ± 44 minvs 298 ± 39 min,P < 0.05) were prolonged in the study group. However, pain scores and the analgesic requirements in the postoperative periods (24 and 48 hr) were similar.

Conclusion

There is a short-term benefit during the first few postoperative hours in using a single shot “3-in-1” femoral nerve block to complement general anaesthesia for elective hip surgery.     

Bupivacaine decreases epidural meperidine requirements after abdominal surgery

Purpose

The purpose of this study was to determine the optimal of three concentrations of bupivacaine (0.0%. 0.05%. 0.10%) to add to an epidural infusion of mependine (1 mg· ml¹) for postoperative pain relief.

Methods

In this prospective, double blind study. 60 patients undergoing abdominal surgery with general anaesthesia were randomized into three groups to receive for postoperative epidural analgesia: 1) 1 mg· ml¹ mependine (0% group). 2) bupivacaine 0.05% and 1 mgml mependine (0.05% group). 3) bupivacaine 0.10% and 1 mg· ml mependine (0 10% group). Postoperatively, the epidural infusion rate was titrated to produce adequate analgesia and pain was assessed at rest and on movement.

Results

There were no differences in demographic data, average pain scores or side effects among the three groups. However, there was improvement of pain relief at rest over time in the three groups (P< 0.05). Postoperative epidural analgesic infusion rates increased over time for the three groups (P< 0.05) and were lower in the 0.10% group (mean of 10.0 ml· hr^?1 than in the 0% group (mean of 12.6 ml·hr¹) (P< 0.05). More than half of the 0% group had serum mependine concentrations >400 g· L^?1 to control moderate postoperative pain.

Conclusion

Although analgesia was identical among groups, the lower serum concentrations of mependine support the addition of bupivacaine 0.10% to mependine when administered as a continuous infusion following abdominal surgery.     

Epidural and intravenous bolus morphine for postoperative analgesia in infants

Purpose

To compare two doses of bolus epidural morphine with bolus iv morphine for postoperative pain after abdominal or genitourinary surgery in infants.

Methods

Eighteen infants were randomly assigned to bolus epidural morphine (0.025 mg · kg^?1 or 0.050 mg · kg^?1) or bolus iv morphine (0.050–0.150 mg · kg^?1). Postoperative pain was assessed and analgesia provided, using a modified infant pain scale. Monitoring included continuous ECG, pulse oximetry, impedance and nasal thermistor pneumography. The CO₂ response curves and serum morphine concentrations were measured postoperatively.

Results

Postoperative analgesia was provided within five minutes by all treatment methods. Epidural groups required fewer morphine doses (3.8 ± 0.8 for low dose [LE], 3.5 ± 0.8 for high dose epidural [HE] vs. 6.7 ± 1.6 for iv, P < 0.05) and less total morphine (0.11 ± 0.04 mg · kg^?1 for LE, 0.16 ± 0.04 for HE vs 0.67 ± 0.34 for iv, P < 0.05) on POD1 Dose changes were necessary in all groups for satisfactory pain scores. Pruritus, apnoea, and haemoglobin desaturation occurred in all groups. CO₂ response curve slopes, similar preoperatively (range 36–41 ml · min^?1 · mmHg ETco ₂ ^?1 · kg^?1) were generally depressed (range, 16–27 ml · min^?1 · mmHg ETco ₂ ^?1 · kg^?1) on POD1. Serum morphine concentrations, negligible in LE (<2 ng · ml^?1), were similar in the HE and iv groups (peak 8.5 ± 12.5 and 8.6 ± 2.4 ng · ml^?1, respectively).

Conclusion

Epidural and iv morphine provide infants effective postoperative analgesia, although side effects are common. Epidural morphine gives satisfactory analgesia with fewer doses (less total morphine); epidural morphine 0.025 mg · kg^?1 is appropriate initially. Infants receiving epidural or iv morphine analgesia postoperatively need close observation in hospital with continuous pulse oximetry.     

Esmolol versus ketamine-remifentanil combination for early postoperative analgesia after laparoscopic cholecystectomy: a randomized controlled trial

Purpose

Controversy surrounds the optimal technique to moderate pain after laparoscopic cholecystectomy (LC). Opioid analgesics, sympatholytic drugs, and adjuvants, such as ketamine, have all been used. We compared esmolol with a combination of remifentanil plus ketamine in patients undergoing LC to determine the impact of these drugs on morphine requirements and pain control.

Methods

Sixty American Society of Anesthesiologists physical status I-II patients undergoing LC and anesthetized with sevoflurane were randomized to one of two groups. Group E patients received a bolus of esmolol 0.5?mg·kg^?1 iv at induction followed by an infusion of 5-15???g·kg^?1·min^?1, and Group R-K patients received a bolus of ketamine 0.5?mg·kg^?1 iv and remifentanil 0.5???g·kg^?1 iv at induction followed by a remifentanil infusion titrated over a range of 0.1-0.5???g·kg^?1·min^?1. All patients received paracetamol, dexketoprofen, and levobupivacaine via infiltration of laparoscopic port sites. After surgery, a predetermined bolus of morphine was administered according to a verbal numerical rating scale (VNRS) for pain intensity. The primary outcome of interest was postoperative morphine requirement.

Results

Median consumption of morphine was higher in Group R-K than in Group E (5?mg [4-6] vs 0?mg [0-2], respectively; P?<?0.001). In the postanesthesia care unit, patients in Group R-K had higher pain scores than patients in Group E (difference in maximum VNRS, -11; 95% confidence interval (CI), -19 to -3). The concentration of sevoflurane to maintain a bispectral index~40 was higher in Group E than in Group R-K (between-group difference 0.3%; 95% CI, 0.15 to 0.40). The incidence of postoperative nausea and vomiting was similar between the two groups.

Conclusion

Intraoperative esmolol infusion reduces morphine requirements and provides more effective analgesia compared with a combination of remifentanil-ketamine given by infusion in patients undergoing LC.     

Propranolol pretreatment reduces cardiorespiratory toxicity due to plain,but not epinephrine-containing,intravenous bupivacaine in rats

The purpose of this study was to evaluate the effects of pretreatment with propranolol on the cardio-respiratory toxicity of bupivacaine, either plain or with epinephrine 1:200,000 (5 μg · ml^{? 1}) added. Adult male Sprague Dawley rats, anaesthetized with intraperitoneal pentobarbital, were divided into four groups. Groups I and III were pretreated with iv propranolol 150 μg · kg^{? 1}, and Groups II and IV recei ved iv NS as a placebo. Three minutes later, rats in Groups I and II received plain 0.5% bupivacaine, 4 mg · kg^{? 1}, and Groups III and IV received 4 mg· kg^{? 1} of 0.5% bupivacaine with epinephrine, 5 μg · ml^{? 1} iv. Five of eight rats pretreated with propranolol survived (Group I), compared with uniform fatality with NS pretreatment (Group II) (P < 0.05). Addition of epinephrine to the bupivacaine eliminated the protective effect of propranolol. All rats pretreated with propranolol (Group III) or NS (Group IV) died when given bupivacaine with epinephrine. In conclusion, acute propranolol pretreatment reduced the fatal cardiotoxicity due to iv bupivacaine in male Sprague Dawley rats, but the addition of epinephrine 5 μg · ml^{? 1} to bupivacaine eliminated the protective effect of propranolol.     

Anaesthesia Equipment Patient controlled oral analgesia with morphine

Purpose

When using strong oral opioids for postoperative pain management, demand titration is desirable. A device for patient controlled oral analgesia (PCORA) and first results of its use for oral titration of morphine are presented.

Methods

The PCORA-device is a modified Baxter-PCA-on-demand system (maximum bolus volume: 0.5 ml; flow rate for filling bolus volume: 0.5 ml · hr^?1). The demand PCORA-volumes were measured at specific time intervals and PCORA was compared with customarily prescribed pain therapy (CPPT) for postoperative pain management. On the first post-operative day, 20 orthopaedic ASA I or II patients received, in a randomised, cross-over trial, either PCORA (300 min) followed by CPPT (300 min) (Group I) or vice versa (Group II). The PCORA-device permitted a maximum dose of 15 mg morphine per 60 min and CPPT was performed by the ward doctor or nurse. Pain intensity (101-point numerical rating scale) and side effects were evaluated at 30 min intervals.

Results

The accuracy of the bolus volume delivered by the PCORA-device was 89.2 ± 0.85% (mean ± SEM), of manufacturer’s specifications. PCORA pain intensity decreased over time whereas CPPT pain intensity did not (P < 0.001). PCORA-morphine requirements were 61.5 ± 5.2 mg (Group I) and 52.5 ± 8.5 mg (Croup II) (NS; mean ± SEM). The handling of the PCORA-device presented no problem to any patient.

Conclusion

Patient controlled oral analgesia is an effective and non-invasive mode of postoperative pain management. The PCORA-device is reliable and easy to use.     

Serum bupivacaine concentrations during continuous extrapleural infusion

Purpose

To determine the rate of increase in serum bupivacaine concentration during continuous extrapleural infusion.

Methods

After thoracotomy for lobectomy under general anaesthesia, nine patients had an extrapleural catheter inserted, before chest closure, in a costovertebral gutter constructed surgically by lifting the panetal pleura. Bupivacaine 0.5% with epinephnne 1:200.000 was injected through the catheter as 0.3 ml·kg^?1 bolus followed by 0.1 ml· kg^?1·hr^?1 for five days. Serum bupivacaine (free and total), albumin, alpha-1 acid glycoprotein concentrations were measured 15 min after injection and at 24 hr intervals for five days. Bupivacaine concentrations were determined by column liquid chromatography using solid phase extraction. Serum alpha-1 acid glycoprotem concentration was determined by nephelometry on QM 300 protein analyzer. Serum albumin concentration was determined by bromocresol green dye binding procedure on Hitachi 717 Autoanalyzer.

Results

A continuous elevation in total serum bupivacaine was observed, with an average value of 0.75 μg· ml on day 1 to 2.77 μg· ml on day 4 (P< 0.05). There was no increase in postoperative free serum bupivacaine concentration; average value of 177 pcg· ml^?1 on day 1 and 249 pcgml^?1 on day 4 (P=0.92). Postoperative serum alpha-1 acid glycoprotein concentration showed a steady rise with an average value of 0.94 μg· ml^?1 on day 1 and 1.47 μg·ml^?1 on day 4 (P< 0.05). No change was observed in post-operative serum albumin with an average value of 31.4 g· l^?1 on day 1 and 31.3 g· l^?1 on day 4.

Conclusion

Continuous extrapleural infusion of bupivacaine over five days after thoracotomy is associated with a steady increase in total serum bupivacaine concentration and no elevation in free serum bupivacaine concentration.     

Respiratory depression after low-dose caudal morphine

Purpose

To report a case of respiratory depression after a small dose of caudal morphine administered to a 15-mo-old child.

Clinical features

A 15 mo, 9.8 kg boy underwent ureteral reimplantation with general endotracheal anaesthesia and 10 ml bupivacaine 0.25% (2.5 mg · kg^?1). Ninety minutes after the bupivacaine, 0.4 mg (1 mg · ml^?1, 0.4 ml, 0.04 mg · kg^?1) preservative-free morphine was injected after negative aspiration. Slighly more than two hours after caudal morphine, the patient became lethargic and developed decreases in oxygen saturation (to 62%) without change in heart rate or respiratory rate. Intravenous naloxone 0.1 mg (0.01 mg · kg^?1) markedly improved his level of consciousness. Racemic epinephrine was administered for treatment of coincident stridor. The patient required 11 hr continuous naloxone infusion (0.001–0.002 mg · kg^?1 · hr^?1) in the intensive care unit. He was discharged on the second postopertive day without further complication.

Conclusion

Respiratory depression can occur in children greater than one year of age, even when small doses of caudal morphine are used. Decreased arterial oxygen saturation and lethargy are important heralds. A normal respiratory rate despite substantial hypoxaemia argues that pulse oximetry (without supplemental oxygen where possible) has a clear advantage over impedance pneumography for electronic monitoring.     

Heart rate changes in cardiac transplant patients and in the denervated cat heart after edrophonium

Purpose

The effect of edrophonium on heart rate in cardiac transplant patients and in an animal model of acute cardiac denervation were studied, to evaluate the functional state of the peripheral parasympathetic pathway fol lowing cardiac denervation.

Methods

Edrophonium was studied in patients with normally innervated hearts (controls) and m cardiac trans plants. Edrophonium was also studied in vagotomized. beta-blocked cats. In Group I animals, the vagus nerve was not stimulated. In Groups 2 & 3 the right vagus nerve was electrically stimulated to produce approximately 20% and 40% reductions in baseline heart rate, respectively.

Results

Maximum heart rate reduction in transplants (7.3 ± 0.8 beats·min^?1 with 0.6 ± 0.08 mg·kg^?1) was less than in controls (13.3 ± 1.6 beatsmm with 0.4 + 0.05 mg·kg^?1, P < 0.01). In Group I animals heart rate decreased maximally by 20.9 ± 2.5 beats·min^?1 with 9.0 ± 1.9 mg·kg^?1. In Groups 2 and 3, with doses < 15 mg·kg^?1, reduc tions m heart rate were greater than in Group I and maximual reductions were obtained with lower doses (Group 2: maximum reduction by 20.3 ± 2.8 beats·min^?1 with 1.3 ± 0.1 mg·kg^?1: Group 3: 22.6 ± 4.0 beats·min^?1 with 0.8±0.2 mg·kg^?1, P < 0.001) Doses > 1.5 mg·kg^?1 in Groups 2 and 3 produced increases in heart rate.

Conclusion

Edrophonium produced bradycardia in cardiac transplants suggesting spontaneous release of acetylcholinee from parasympathetic postganglionic neurons m the transplanted heart. The magnitude of the brady cardia was less in transplant than in control patients. Findings from animal studies suggest that the reduction in transplants can be attributed to diminution or absence of tonic cardiac parasympathetic drive. At high doses, edrophonium may interfere with parasympathetic neuron activation.     

Analgesia after otoplasty: regional nerve blockade vs local anaesthetic infiltration of the ear

Purpose

Children scheduled to undergo otoplasty experience severe pain postoperatively. Nausea and vomiting is also a problem. This study was designed to compare two analgesic techniques (i) regional nerve blockade (ii) local anaesthetic infiltration, with respect to quality and duration of analgesia, opioid requirements and the incidence of postoperative nausea and vomiting (PONV).

Methods

Forty three children, ASA I–II, aged 3–15 yr, were studied and followed for 24 hr postoperatively. Patients were randomised into two groups. Patients in Group A received local infiltration with lidocaine 1% with adrenaline 1:200,000 0.4 ml·kg^?1 (n = 21). Patients in Group B (n = 22) received nerve blockade, bupivacaine 0.5%, 0.4 ml·kg^?1. No other form of analgesia was used intraoperatively. Quality and duration of analgesia were assessed using pain and sedation scores recorded by a blinded observer at 0, 5, 10, 15, 30, 45 min with Recovery Room, and at 0, 30, 60, 90, 120, 180, 240, 360, 480 min on the ward. Pain score > 6 was treated with fentanyl 1 μg·kg^?1 iv (recovery) and morphine 0.2 mg·kg^?1 im or mefenamic acid 8 mg · kg^?1 po on the ward. Time to first supple-mental analgesia was noted. Mean duration of analgesia was 8.6 (1,1–24) hr, Group A and 10.5 (1,3–24) hr, Group B (P > 0.7). 24% per cent of children (Group A) and 27% (Group B) required no supplemental analgesia (P > 0.6). The degree of pain control resulted in a low requirement for opioids, Group A: 24%, Group B: 14% (P:NS). The overall incidence of PONV was 43% (Group A) and 36% (Group B) (P:NS): PONV correlated with opioid use. There were no differences between the groups with regard to pain/sedation scores, quality/duration of analgesia, opioid requirements and incidence of PONV.

Conclusion

Both techniques provided excellent postoperative analgesia. Lidocaine 1% infiltration (adrenaline 1:200,000) has the added advantage of improving surgical field and haemostasis. Thus, we advocate use of the simpler technique.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

Analgesia following appendicectomy — the value of peritoneal bupi-vacaine

Purpose

Peritoneal inflammation is an important feature in many patients presenting with appendicitis. The contribution of peritoneal nerve fibres to pain experienced after appendicectomy has received little attention.

Method

In this prospective double blind randomized study a consecutive series of 60 patients undergoing appendicectomy for suspected appendicitis were enrolled. A dose of 1.5 mg·kg^?1 bupivacaine 0.5 % was used. Group one patients received the entire dose of bupivacaine subcutaneously. Group two patients received half the dose subcutaneously (sc) and half the dose to the peritoneum. Pain scores were assessed pre-operatively and at 30 min, 12 and 24 hr post-operatively using a visual analogue scale. Time to first analgesia and total analgesia requirements in the first 24 hr were recorded.

Results

The patients receiving the sc combined with peritoneal bupivacaine had a lower pain score 30 min postoperatively (32 ± 2 vs 54 ± 4;P < 0.0001), a longer time to first analgesia (248 ± 20 vs 164 ± 17 min; P = 0.002)as well as lower opioid (68 ± 5 vs 100 ± 7 mg; P = 0.0002) and non steroidal analgesic requirements (65 ± 6 vs 96 ± 6 mg; P = 0.007) in the first 24 hr post-operatively.

Conclusion

A combination of sc and peritoneal infiltration with bupivacaine is superior to skin infiltration alone in the relief of pain post appendicectomy.     

Fasciculations, myalgia and biochemical changes following succinylcholine with atracurium and lidocaine pretreatment

Purpose

To determine the attenuation in the incidence of myalgia, fasciculations and changes in serum potassium and creatinine kinase concentrations when atracunum and lidocaine were used in combination and separately as pretreatment before succinylcholine.

Method

In a prospective, double blind randomized study, 80 ASA I patients 20–50 yr were assigned to one of four groups. Anaesthesia was induced with thiopentone and fentanyl. Group C received placebo pretreatment before 1.5 mg·kg^?1 succinylcholine: Group A 0.05 mg·kg^?1 atracunum three minutes before; Group L, 1.5 mg·kg^?1 lidocaine 30 sec before; and group AL both atracurium and lidocaine. Serum potassium five minutes after succinylcholine. and creatinine kinase 24 hr after operation were measured and the increases from preinduction values were compared. Fasciculations and postoperative myalgia at 24 and 48 hr were recorded. Patients receivediv mependine orpo paracetamol for postoperative analgesia.

Results

The increase in serum potassium concentration (0.36 ± 0.23 mEq·l^?1) was not attenuated by any regimen (P < 0.05). The incidence of fasciculations (P < 0.05) and the increase in creatinine kinase (P < 0.01) was less in the atracunum (40%; 20.93IU·I^?1) and atracunum-lid ocaine (30%; 22.85IU·I^?1) than in the lidocaine (85%; 45.01IU·I^?1) and control (100%; 56.05 IU·I^?1) groups. Postoperative myalgia on Days 1 and 2 was lowest (P < 0.05) in the atracurium-lidocaine group (5%; 0%) followed by the atracurium (35%; 25%) and lidocaine (30%; 35%) groups and highest in the control (75%; 65%).

Conclusion

Atracurium and lidocaine individually reduce postoperative myalgia, with further decrease occurring when used together.     

Supplementation of general anaesthesia with tramadol or fentanyl in parturients undergoing elective Caesarean section

Purpose

Tramadol has been recommended for analgesia in parturients undergoing vaginal delivery. The present report investigated the effect of tramadol versus fentanyl on umbilical vein (UV) blood gases and Apgar scores of neonates delivered via elective Caesarean section under general anaesthesia.

Methods

Forty ASA I or II parturients undergoing elective Caesarean section were included in a randomized double-blinded study. The patients were divided into a tramadol (n = 20) and fentanyl groups (n =.20). During preoxygenation, one group received 100 mg tramadoliv, while the second received 100 μg fentanyl. Anaesthesia was induced in both groups by 3 mg·kg^?1 thiopentone and 1.5 mg·kg^?1 succinylcholine was given to facilitate tracheal intubation. Anaesthesia was maintained during the induction-delivery period with nitrous oxide 50% in oxygen.

Results

The umbilical vein PO₂ was higher in the fentanyl (34 ± 5 mmHg) than in the tramadol group (24 ± 6 mmHg) (P < 0.01), while the UV PCO₂ was higher in the tramadol group (50 ± 5vs 45 ± 4 mmHg) (P 0.01). The Apgar scores at one and five minutes were not different between the two groups. Post operatively, two patients in the tramadol group recalled the crying of their newborn at delivery.

Conclusion

Tramadol is associated with a high incidence of intraoperative maternal recall and can result in lower umbilical vein PO₂ and higher PCO₂ than in the fentanyl group.     

Epidural administered buprenorphine in the perioperative period

Purpose

To study the effect of epidural buprenorphine on minimum alveolar concentration (MAC) of volatile anaesthetics, duration of analgesia and respiratory function in the perioperative period.

Methods

One hundred and twenty patients, ASA I–II undergoing gynaecological surgery were randomly divided into three studies. The forty patients in each study were randomly divided into four groups depending on the dosage; Group I (control), Group II (80 μg · kg^?1 morphine), Group III (4 μg · kg^?1 buprenorphine), Group IV (8 μg · kg^?1 buprenorphine). The MAC of halothane was measured following epidural administration of the agents in each group. The duration of analgesia was assessed by the first request for pentazocine. Postoperative analgesic effects were assessed by the total dosage of pentazocine required for the 48 hr after surgery. Respiratory rate (RR), minute volume (MV), and PaCO₂ were measured during surgery and the postoperative period. The MAC of halothane was reduced in Group IV (P < 0.01). The duration of analgesia was 10.0 ± 5.1 hr (Mean ± SE) in Group 1, 37.7 ± 4.7 hr in Group II, 27.1 ± 7.1 hr in Group III, and 44.4 ± 4.1 hr in Group IV. Total dosage of pentazocine was lower in Group IV (P < 0.05) than in the other groups. The decrease of RR, MV and the increase of PaCO₂ were observed within 60 min in Group III and IV dose dependently.

Conclusion

Epidural buprenorphine administered in a dose of 4 or 8 μg · kg^?1 provides postoperative analgesia that is no less effective than that of morphine.