Biomedical subjects
M Harmer
Publications and source records attributed to M Harmer.
A new gas jet method for the assessment of sensory block after spinal anaesthesia.
We evaluated a new method of assessing sensory block after spinal anaesthesia using a fine gas jet and compared it with other established methods. The gas jet method was used to test the block before and after surgery and was found to compare favourably with pin-prick (median difference 0 and 0 dermatomes) and ethyl chloride (median difference 0.5 and 1.0 dermatomes) but less well with cotton wool (median difference -2.0 and -2.0 dermatomes).
A change in resistance? A survey of epidural practice amongst obstetric anaesthetists.
Five hundred members of the Obstetric Anaesthetists Association were surveyed regarding their technique for identification of the epidural space. Eighty-one per cent of the questionnaires were returned completed. Fifty-nine per cent of respondents first learned a loss of resistance to air technique, 33.4% to saline and 7.4% another technique. Presently, 37.1% and 52.7% use only a loss of resistance to air or saline, respectively. Six per cent use both techniques and 3.2% use other techniques. Twenty-eight per cent taught a loss of resistance to air, 57.2% taught a loss of resistance to saline and 12.9% taught both techniques. Twenty-three per cent changed from a loss of resistance to air, to a saline technique, and 4.2% vice versa. Forty-seven per cent of those using air felt that loss of resistance to air was not associated with a clinically significant difference in the incidence of accidental dural puncture compared with saline.
The effect of education, assessment and a standardised prescription on postoperative pain management. The value of clinical audit in the establishment of acute pain services.
A study involving 2738 patients in 15 hospitals in the United Kingdom was undertaken to evaluate the effect of simple methods of pain assessment and management on postoperative pain. The study consisted of four parts: a survey of current practice in each hospital; a programme of education for staff and patients regarding pain and its management; the introduction of formal assessment and recording of pain and the use of a simple algorithm to allow more flexible, yet safe, provision of intermittent intramuscular opioid analgesia; and a repeat survey of practice. One hospital from each of the former health regions of England and Wales was selected for inclusion in the project. Hospitals included representatives of different size units (university, large and small district general hospitals). As a result of the study, there was an overall reduction in the percentage of patients who experienced moderate to severe pain at rest from 32% to 12%. The incidence of severe pain on movement decreased from 37% to 13% and moderate to severe pain on deep inspiration from 41% to 22%. Similar decreases were seen in the incidence of nausea and vomiting. There was also a slight reduction in the incidence of postoperative complications. This study shows that simple techniques for the management of postoperative pain are effective in reducing the incidence of pain both at rest and during movement and should form part of any acute pain management strategy.
Comparison between halothane and sevoflurane for adult vital capacity induction.
We have examined the differences in ventilatory characteristics between halothane and sevoflurane when used for adult vital capacity induction of anaesthesia. The study was conducted in a randomized, double-blind manner. After 13 patients had been enrolled, the study was curtailed because the blinded observer thought that there was an unacceptably high incidence of adverse events. After the randomization code was revealed, the adverse events were found to be in the halothane group. Although the sample size was small, minute volumes appeared to be maintained in the sevoflurane group. Ventilatory frequencies were similar in the two groups after insertion of the laryngeal mask airway, but tidal volumes were significantly greater in the sevoflurane group (P = 0.0013).
Environmental monitoring during gaseous induction with sevoflurane.
Recent research has shown that gaseous induction in adults with sevoflurane is an acceptable technique. This study was undertaken to assess if gaseous induction using sevoflurane carried in both oxygen alone, and in nitrous oxide and oxygen combined, would provide acceptable pollution levels. As an occupational exposure standard has not been set for sevoflurane, we used the target level of 20 ppm set by the manufacturer. Environmental monitoring was carried out in the anaesthetic room during eight lists where consecutive triple vital capacity sevoflurane inductions were performed. Time-weighted averages for both gases over the duration of the lists were well below the occupational exposure standards (mean 1.1 (range 0.6-1.7) for sevoflurane and 17.3 (12-23) for nitrous oxide). There were high peak concentrations during the induction process (8.3 (4.1-17) for sevoflurane and 172.4 (65-310) for nitrous oxide) although these decreased to low concentrations between anaesthetic inductions. Personal sampling was carried out from the anaesthetist's breathing zone and concentrations were also low (1.2 (0.8-2.1) for sevoflurane and 45.9 (10.1-261.6) for nitrous oxide.
Single-breath inhalation induction of sevoflurane anaesthesia with and without nitrous oxide: a feasibility study in adults and comparison with an intravenous bolus of propofol.
The induction characteristics of sevoflurane in nitrous oxide and oxygen were compared with sevoflurane in oxygen alone and a propofol infusion. A vital capacity technique was used for the gaseous induction groups using a Mapleson A system and a 4-litre reservoir bag. Four end-points of anaesthesia were recorded: time to cessation of finger tapping, time to loss of eyelash reflex, time to jaw relaxation and time to regular settled breathing after laryngeal mask airway insertion. We also recorded sequential blood pressure and pulse rate, the incidence of adverse airway events and the acceptability of the induction technique. Propofol had a faster time to cessation of finger tapping (p < 0.05) and jaw relaxation (p < 0.01). These differences disappeared with the final induction stage and sevoflurane in nitrous oxide and oxygen had the faster time to regular settled breathing, though this did not reach statistical significance. Cardiovascular stability was good and comparable in all groups. There were few adverse airway events in any group and none caused oxygen saturation to fall below 96%. There was more excitation in the gaseous induction groups, though this did not interfere with induction. Patient satisfaction with induction was high.
Maternal mortality--is it still relevant?
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Erythromycin as a prokinetic agent in children.
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Tachypnoea following vital capacity induction with sevoflurane.
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A comparison of opioid solutions for patient-controlled epidural analgesia.
Sixty patients took part in a randomised, double-blind study to compare the analgesic and side effects of three opioid-containing solutions for patient-controlled epidural analgesia following abdominal surgery. Patients in group 1 received a solution containing bupivacaine 0.125% with fentanyl 10 micrograms.ml-1, group 2 bupivacaine 0.125% with diamorphine 125 micrograms.ml-1, group 3 pethidine 2.5 mg.ml-1. All groups received 4 ml.h-1 background infusion and 3 ml boluses every 20 min if necessary. There were no significant differences between the groups in visual analogue scale pain scores (p = 0.537) or volumes of solution used at 24 h (p = 0.351) or 48 h (p = 0.105). Motor block was significantly higher in group 2 (p < 0.004) and pruritus occurred significantly less in group 3 (p < 0.05). We conclude that these three solutions produce equivalent analgesia but that pethidine 2.5 mg.ml-1 may be associated with fewer side effects.
A survey of acute pain services in the United Kingdom.
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Overdosage during patient controlled analgesia. Follow manufacturers' instructions.
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Nausea and vomiting after gynaecological surgery: a meta-analysis of factors affecting their incidence.
A total of 1442 patients who had major gynaecological surgery were recruited into three multicentre studies using a standard general anaesthetic technique in order to assess the efficacy of various doses of orally administered ondansetron in the prevention of postoperative nausea and vomiting. A total of 1257 patients were included in this analysis: 420 received oral formulations of placebo and 212, 296 and 329 received ondansetron 1, 8 and 16 mg, respectively. The following factors were measured in these studies and were considered to have a possible influence on the proportion of patients experiencing postoperative nausea and vomiting: age of patient; volatile anaesthetic; intraoperative dose of fentanyl; postoperative dose of morphine; country; anaesthesia duration; neuromuscular blocker; neuromuscular block antagonist; premedicant; recovery time; type of surgery; antiemetic treatment; body weight. Using a process of elimination based on logistic regression techniques, the factors found to be the most important influences on the frequencies of nausea and vomiting were antiemetic treatment, type of surgery, neuromuscular blocker, country, volatile anaesthetic and age. A statistically significant interaction between type of surgery and age was observed. Adjusted probabilities of nausea and vomiting were obtained from the model, including all the above factors, together with the type of surgery by age interaction. Ondansetron 8 mg showed the smallest adjusted probability of nausea (0.54) and vomiting (0.34) and placebo the greatest (nausea 0.75, vomiting 0.61). A similar pattern of adjusted probabilities over neuromuscular blocking agents was seen for nausea and vomiting, with the greatest occurring in patients receiving pancuronium (nausea 0.74, vomiting 0.57) and the least in patients receiving alcuronium (nausea 0.59, vomiting 0.38).(ABSTRACT TRUNCATED AT 250 WORDS)
A comparison between mivacurium and suxamethonium in children.
The neuromuscular effects of mivacurium were compared with those of suxamethonium in 69 children (aged 2-12 years), during nitrous oxide, oxygen and halothane anaesthesia in a randomised open study. Neuromuscular block was monitored by measuring the acceleration of the thumb caused by contraction of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve at the wrist using an Accelograph. End-tidal carbon dioxide was maintained at about 4 kPa in both groups. The mean times (95% confidence intervals) for T1:T0 ratio to decrease to 75%, 50%, 25% and 5% of control values were 50 (42-59), 62 (52-74), 83 (68-100) and 93 (46-108) s respectively for mivacurium and 18 (15-22), 26 (22-30), 32 (28-37) and 43 (38-49) s respectively for suxamethonium. The times for T1:T0 ratio to recover to 25%, 50% and 70% of control values were 615 (542-698), 769 (687-859) and 901 (820-993) s respectively for mivacurium and 196 (179-214), 216 (201-234) and 242 (216-259) s respectively for suxamethonium. The range of maximum block was similar for both drugs. The average time to reach maximum block was 143 s for mivacurium and 56 s for suxamethonium. Intubating conditions were similar in the two groups.
Policy for controlling pain after surgery: effect of sequential changes in management.
OBJECTIVE: To observe the effects of introducing an acute pain service to the general surgical wards of a large teaching hospital. DESIGN: A study in seven stages: (1) an audit of current hospital practice succeeded by the sequential introduction to the general surgical wards of (2) pain assessment charts; (3) an algorithm to allow more frequent use of intramuscular analgesia; (4) increased use of local anaesthetic techniques of wound infiltration and nerve blocks; (5) an information sheet for patients about postoperative pain; (6) the introduction of patient controlled analgesia; (7) a repeat audit of hospital practice. Data were collected on each patient 24 hours after operation. SETTING: University Hospital of Wales, which has both district general and tertiary referral functions. PATIENTS: 2035 patients over nine months from all surgical specialties (excluding cardiac) at the hospital. General surgical operations were studied in detail and separated into major, intermediate, and minor for data collection. MAIN OUTCOME MEASURES: A change in the median visual analogue pain scores 24 hours after surgery for pain during relaxation, pain on movement, and pain on deep inspiration at each stage of the study. RESULTS: There was a reduction in median visual analogue scores during the study. The median (95% confidence interval) scores for pain during relaxation decreased from 45 (34 to 53) in stage 1 to 16 (10 to 20) in stage 7 for major surgical procedures. Pain on movement decreased from 78 (66 to 80) to 46 (38 to 48), and pain on deep inspiration decreased from 64 (48 to 78) to 36 (31 to 38). The reductions in median scores for intermediate and minor operative procedures showed similar patterns. CONCLUSIONS: The introduction of an acute pain service to the general surgical wards led to considerable improvement in the level of postoperative pain as assessed by visual analogue scores. Simple techniques of regular pain assessment and the more frequent use of intramuscular analgesia as a result of using an algorithm were particularly effective.