A comparison of the maintenance and recovery charcateristic of sevoflurane-nitrous oxide against isoflurane-nitrous oxide anaesthesia.

BACKGROUND: To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients. METHOD: This is a prospective, open labelled, randomized, controlled study. Sixty unpremedicated ASA I or II patients (aged 18-50 years), scheduled for elective breast lump excision were randomly allocated to receive either isoflurane or sevoflurane for the maintenance of anaesthesia following fentanyl and propofol intravenous induction. The systolic, diastolic, mean arterial blood pressure and heart rate were measured. The speed of recovery was measured by time to eye opening, time to following simple command, and time to correctly giving own names and address. The incidence of postoperative complication was also recorded. RESULTS: The trend of systolic blood pressure was significantly higher in the isoflurane group as compared to the sevoflurane group for the duration of anaesthesia (p < 0.001, by ANOVA for repeated measurement) but the trend of heart rate was similar for both groups. The recovery time was faster in the isoflurane group. [mean time of eye opening (SD) = 6.8 (2.2) vs 10.7 (4.4) min, p < 0.001; mean time of sticking tongue out (SD) = 7.9 (2.9) vs 11.5 (4.7) min, p < 0.01; mean time of giving own name (SD) = 7.8 (2.7) vs 11.8 (4.8) min, p < 0.001, mean time of giving own address (SD) = 8.4 (2.9) vs 12.0 (4.7) min, p < 0.01]. No major adverse effects were encountered postoperatively and the incidences of minor adverse effects were low in both groups. CONCLUSION: We concluded that sevoflurane is a safe alternative to isoflurane but in these short procedures, awakening time was surprisingly slower than after isoflurane.

A comparison of the induction and emergence characteristics of sevoflurane and halothane in children.

This open labelled, randomised, controlled study was designed to compare the induction and recovery characteristics of sevoflurane and halothane anaesthesia in children. Forty American Society of Anaesthesiologist (ASA) physical status class 1 or 2 children (aged 1-10 year, weighed less than 25 kg) scheduled for elective urological procedure lasting less than one hour were allocated randomly to receive either sevoflurane (group S, n = 20) or halothane (group H, n = 20). The induction time in children receiving sevoflurane was significantly shorter than in those receiving halothane (mean (SD) 46 (13.6) second vs 69 (19.4) seconds, p < 0.005). The emergence from anaesthesia was also faster in children receiving sevoflurane than in those receiving halothane (mean (SD) 9 min (4.3 min) vs 21 min (8.9 min), p < 0.001). No major adverse effects were encountered in each group. We concluded that sevoflurane is comparable to halothane in Malaysian children.

The effect of mivacurium pretreatment on intra-ocular pressure changes induced by suxamethonium.

Forty patients without eye disease, undergoing elective nonophthalmic surgery, were studied in a double-blind, randomised, placebo-controlled study evaluating the efficacy of mivacurium pretreatment in attenuating the rise in intra-ocular pressure in response to suxamethonium administration, laryngoscopy and intubation. The patients were randomly allocated to receive either mivacurium 0.02 mg.kg-1 or normal saline as pretreatment 3 min before a rapid sequence induction technique using alfentanil, propofol and suxamethonium. Suxamethonium induced a significant increase in intra-ocular pressure in the control group but not in the mivacurium pretreatment group (mean (SEM) increase = 3.5 (1.2) mmHg vs. 0.4 (0.8) mmHg, p < 0.05). There was a decrease in intra-ocular pressure in both groups after laryngoscopy and intubation with no significant difference between the two groups. These results show that mivacurium pretreatment is effective in preventing the increase in intra-ocular pressure after suxamethonium administration.

Endotracheal tube ignition during CO2 laser surgery of the larynx.

We report a case of endotracheal tube fire occurring during CO2 laser surgery of the larynx. The ignition of an endotracheal tube was thought to be caused by laser penetration of an unprotected portion of the tube during resection of vocal cord tumour. Fire hazard is inevitable when a laser is used in the path of combustible gases and in the presence of flammable objects. We discuss the methods of prevention that were used.

First year's experience with an acute pain service--University Hospital Kuala Lumpur.

An Acute Pain Service (APS) was started in University Hospital, Kuala Lumpur by the Department of Anaesthesiology in October 1992 for more effective control of postoperative pain. The main modalities of treatment included patient controlled analgesia (PCA) using morphine or pethidine with PCA devises, epidural opiate analgesia (EOA) using tramadol or fentanyl/bupivacaine mixture and subcutaneous administration of morphine or pethidine. Five hundred and fifty-one patients were managed in the first year, with an overall patient satisfaction score of 83%. The majority (98.5%) of them were after abdominal or major orthopaedic surgery. Eighty per cent of patients scored < 3 on the verbal numeric pain scale, where 0 is no pain and 10 is the worst imaginable pain, on the first postoperative day. Nausea and vomiting was an unpleasant side effect in 20% of patients.

Blood cholinesterase levels in a group of Malaysian blood donors.

Data on blood cholinesterase levels in the Malaysian population is lacking. The spectrophotometric method of Ellman was used to determine the red cell, plasma and whole blood cholinesterase (ChE) levels in 407 Malaysian blood donors. The mean+1SD for plasma ChE in females (n = 48) was 2.37 + 0.70 umol/min/ml and 2.76 + 0.75 umol/min/ml in males (n = 359). The mean plasma ChE in males was higher than in females (p < 0.001). The mean+1SD for red cell ChE in females was 9.01 + 1.20 umol/min/ml whereas in males it was 7.69 +1.30 umol/min/ml (the mean red cell ChE in females was higher than in males, p < 0.0001). The mean+1SD for whole blood ChE for females was 4.31+ 0.58 umol/min/ml and for males it was 4.95 + 0.71 umol/min/ml. The mean whole blood ChE in males was higher than in females (p < 0.0001). Sex influenced the plasma, red cell and whole blood ChE. In males the plasma ChE was affected by the race factor. The mean+1SD plasma ChE for the Malay, Chinese and Indian were 2.92 + 0.80, 2.73 + 0.71 and 2.61+ 0.73 respectively (p < 0.002). The age factor in males affected the red cell ChE with 7.88 + 1.32 in the (30-69) age group and 7.47 + 1.23 in the (15-29) age group (p < 0.005). The whole blood ChE in females was affected by blood groups. The mean+1SD whole blood ChE for blood groups A,B and O were 4.19 + 0.42, 3.93 + 0.46 and 4.49 + 0.62 respectively (p < 0.03). The significant difference is between the ChE of group B and O, but the ChE of group A could not be determined to be different from group B or O. These results serve as guidelines for our local population in the evaluation of cholinesterase levels with regard to pesticide poisoning, liver biosynthetic capacity and unusual sensitivity to succinylcholine.

Epidural anaesthesia for caesarean section: a comparison of 0.5% bupivacaine plain, 0.5% bupivacaine plus 100 micrograms fentanyl and 0.5% bupivacaine plus 50 micrograms fentanyl.

Thirty-one healthy women who underwent Caesarean section were studied in a double-blind trial to compare the effectiveness of epidural 0.5% bupivacaine plain, 0.5% bupivacaine plus 100 micrograms fentanyl and 0.5% bupivacaine plus 50 micrograms fentanyl in the prevention of intraoperative pain. There was no difference in the quality of analgesia between the three groups. The incidence of complications was significantly higher in the 0.5% bupivacaine plus 100 micrograms fentanyl group compared with the other two groups.

Risk of anaesthesia--a review.

Modern anaesthesia carries a definite although small risk. The risk from general and regional anaesthesia is reviewed, the causes explored, and preventive strategies discussed. Although anaesthesia may never be 100% safe, a knowledge of the risk and causes enables us to work towards this goal.

Anaesthetic contribution to deaths in the operating theatre at the University Hospital Kuala Lumpur--a retrospective survey.

From January 1980 to August 1992, there were 125 deaths occurring in the operating theatre at the University Hospital Kuala Lumpur. Out of these 125, six were judged to have been mainly 'due to anaesthesia.' In the same time period, there were a total of 155,000 anaesthetics given in the hospital. This gives an anaesthetic death rate (in the operating theatre) of six out of 155,000 or 0.39:10,000.

Melioidosis pneumonia and blast injury.

We present the case of a 24-year-old woman with acute septicemic melioidosis resulting from inhaled infective dust during a blast injury. With appropriate antibiotic treatment and supportive therapy in the ICU, the patient made an uneventful recovery.

Epidural tramadol for postoperative pain relief.

The efficacy of epidurally administered tramadol hydrochloride, a weak centrally acting analgesic, was studied for the relief of postoperative pain. Sixty patients undergoing abdominal surgery were randomly allocated to three treatment groups to be given the following agents by the epidural route: group 1 tramadol 50 mg; group 2 tramadol 100 mg; group 3 10 ml of bupivacaine 0.25%. The drugs were administered at the patients' request with each patient being allowed four doses in the first 24 h following surgery. Blood pressure, pulse rate, respiratory rate, arterial blood gas analyses, pain scores, the interval between doses and the occurrence of any side effects were recorded. Pain scores (assessed using a visual analogue scale) were significantly less (p < 0.05) at 3, 12, and 24 h in patients receiving tramadol 100 mg than in those receiving tramadol 50 mg or bupivacaine. The mean interval between doses for groups 1, 2 and 3 was 7.40 h, 9.36 h and 5.98 h respectively. The mean interval in group 2 was significantly longer than in group 3 (p < 0.05). The incidence of nausea and vomiting in group 2 was significantly higher than in group 3 (p < 0.05).

Incidence of postdural puncture headache. A prospective study of 101 spinal anaesthetics in orthopaedic patients.

Spinal anaesthesia was performed on 101 patients with a 25-Gauge (0.52 mm) needle. We found a 13.9% overall incidence of postdural puncture headache (PDPH) in an orthopaedic population whose mean age was 33.6 years. This incidence is too high and an alternative technique may be needed.

Repair of tracheal tear during oesophagectomy using the mobilised stomach.

Tracheal tears are not as uncommon as initially thought. The resultant insufficiency and hypoxia can be life-threatening. The keystone in management is early recognition and diagnosis. Immediate surgical repair is essential.