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Biomedical subjects

J W Dundee

Publications and source records attributed to J W Dundee.

At least 73 records · Page 4Linked to original sources
PubMed1986

Traditional Chinese acupuncture: a potentially useful antiemetic?

Two consecutive studies were undertaken to evaluate the effectiveness of acupuncture as an antiemetic used in addition to premedication with opioids in patients undergoing minor gynaecological operations. In the first study 25 of the 50 patients underwent acupuncture immediately after premedication with 100 mg meptazinol, the rest receiving the drug alone, and in the second 75 patients were allocated randomly to one of three groups: a group receiving 10 mg nalbuphine and acupuncture, a group receiving premedication and dummy acupuncture, and a group receiving premedication alone. Manual needling for five minutes at the P6 acupuncture point (Neiguan) resulted in a significant reduction in perioperative nausea and vomiting in the 50 patients who underwent acupuncture compared with the 75 patients who received no acupuncture. These findings cannot be explained, but it is recommended that the use of acupuncture as an antiemetic should be explored further.

Acupuncture Therapy↗
PubMed1986

A method for producing constant plasma concentrations of drugs. Application to methohexitone.

A delivery system in which a dilute infusion of methohexitone is continuously added to a smaller volume of more concentrated solution has been used to infuse exponentially decreasing drug concentrations at a constant rate of infusion. The constants for calculation of concentrations and infusion rate are described. It was possible to achieve and maintain the target plasma concentration required to produce anaesthesia in conjunction with nitrous oxide in oxygen. Methohexitone is the only available drug suitable for this technique, but it requires frequent opioid supplementation and is not the ideal drug for such a technique.

Anesthesia, General↗
PubMed1986

Effect of pretreatment with ranitidine on the hypnotic action of single doses of midazolam, temazepam and zopiclone. A clinical study.

Patients receiving midazolam, temazepam or zopiclone by mouth as premedication for minor gynaecological surgery were pretreated with either ranitidine or an inert tablet. Pretreatment with ranitidine was associated with a greater degree of drowsiness at 20 and 40 min after midazolam, and a shorter mean time to peak hypnotic effect than in the non-pretreated group. Ranitidine did not affect the degree of drowsiness in the patients receiving temazepam or zopiclone.

Adolescent↗
PubMed1986

Comparison of induction characteristics of four intravenous anaesthetic agents.

The induction characteristics of thiopentone, etomidate and methohexitone have been compared to those of propofol (2,6 di-isopropyl phenol) in unpremedicated patients. Propofol 2.5 mg/kg caused significantly more hypotension, excitatory side effects and pain on injection at the dorsum of hand than thiopentone 5 mg/kg. However, with regard to the latter two sequelae, etomidate 0.3 mg/kg and methohexitone 1.5 mg/kg caused similar or more frequent upset. Propofol 2.0 mg/kg was equipotent with thiopentone 4.0 mg/kg in terms of successful induction of anaesthesia. Hypotension may contraindicate the use of propofol in the hypovolaemic or unfit patient.

Adult↗
PubMed1986

A double-blind comparison of intramuscular pethidine and nalbuphine in labour.

A double-blind, between-patient comparison of intramuscular pethidine 100 mg and nalbuphine 20 mg for the relief of pain during labour in 80 patients is described. Severity of pain was assessed before and after treatment by subjective pain scores and visual analogue scales. Neither of these methods showed a significant difference between the treatments. Nalbuphine was associated with less maternal nausea and vomiting than pethidine, but this possible advantage was somewhat offset by a tendency of the drug to produce more maternal sedation and dizziness. The mean umbilical vein/maternal vein ratio was significantly higher for nalbuphine (0.78, SEM 0.03) than for pethidine (0.61, SEM 0.02), which suggests easier placental transfer of the former. This finding was reflected in significantly lower 2-4 hour neurobehavioural scores for the infants of mothers given nalbuphine, but there was no significant difference between these scores at 24 hours. On the basis of this study, nalbuphine does not offer a substantial improvement over pethidine for pain relief in labour.

Adult↗
PubMed1986

Pretreatment with opioids. The effect on thiopentone induction requirements and on the onset of action of midazolam.

Pretreatment with small doses of fentanyl (100 micrograms) or alfentanil (300 micrograms) was found significantly to reduce the induction dose of thiopentone. Fentanyl 50 micrograms and alfentanil 150 micrograms also significantly reduced the onset time and increased the consistency of action of midazolam. Respiratory depression was not a problem when 50 micrograms fentanyl or 150 micrograms alfentanil were used.

Adolescent↗
PubMed1986

Sensitivity to propofol in the elderly.

Two studies were carried out on 609 fit, unpremedicated patients to assess the influence of patient age on the response to the rapidly-acting hindered phenol, propofol, which is being evaluated for induction of anaesthesia. In the first study, 1.25 mg/kg was injected over 20 seconds followed by 10-mg increments every 15 seconds until loss of verbal contact. This showed a great individual variation in response to the drug. A reduction in the 'induction' dose was found in elderly patients, which became marked around 60 years. In the second (340), doses ranging from 1.5-3.0 mg/kg in patients under 60 years and 1.25-2.25 mg/kg in those over 60 years were injected as a bolus over 20 seconds. Doses of 2.25-2.5 mg/kg were required to induce anaesthesia in patients under 60 years, whilst 1.5-1.75 mg/kg was adequate in those over 60 years. Side effects were more marked with the rapid injection and doses in excess of 1.75 mg/kg caused significant hypotension and apnoea in the elderly. These studies reveal marked sensitivity to propofol in the elderly with respect to both induction dose and acute toxicity.

Adult↗
PubMed1986

Prolonged midazolam elimination half-life.

The pharmacokinetics of a fixed dose of midazolam (0.3 mg kg-1 i.v.) were studied in detail in 115 healthy patients or volunteers and nine were found with a prolonged elimination half-life. A further 102 patients had an abbreviated pharmacokinetic study, of whom five showed a similar abnormality. Defective hepatic metabolism of midazolam may be a factor in the aetiology of what appears to be a true phenomenon, occurring in 6% of over 200 fit subjects given a standard dose of the drug.

Benzodiazepines↗
PubMed1986

Bioavailability of three formulations of intravenous diazepam.

It has been generally assumed that the bioavailability of different formulations of intravenous diazepam is identical. In a within-subject crossover study using eight healthy volunteers, we have found that both the initial and the overall plasma diazepam levels are significantly lower after both emulsion (Diazemuls) and micelle preparations than after an organic formulation (Valium). These findings are relevant to the interpretation of the results of past, present and future clinical studies involving intravenous diazepam. The studies with Valium and Diazemuls confirm the clinical impression of the lesser potency of the latter formulation.

Adult↗
PubMed1986

Maternal stress response associated with caesarean delivery under general and epidural anaesthesia.

The maternal stress response to caesarean delivery with either general or epidural anaesthesia was investigated. Patients given a general anaesthetic showed statistically significant increases in blood pressure, heart rate, and levels of plasma catecholamines, cortisol and glucose. Epidural anaesthesia, to at least the T6 dermatome, obtunded these responses. The significance of these findings to the choice of method of anaesthesia is discussed.

Anesthesia, Epidural↗
PubMed1986

The influence of cyclizine and perphenazine on the emetic effect of meptazinol.

The effectiveness of 50 mg cyclizine and 2.5 mg perphenazine against the emetic sequelae of 100 mg meptazinol were studied in a randomized double-blind placebo-controlled trial. Three groups of 40 women received the opioid, together with an anti-emetic by i.m. injection, as premedication prior to minor gynaecological surgery. Beneficial or noxious effects were noted at standard time intervals and anaesthesia standardized as incremental methohexitone with nitrous oxide/oxygen. In the placebo group, 33 out of 40 subjects experienced either nausea or vomiting at some time after the opioid. Cyclizine, 50 mg, provided significant reduction of emetic tendency in both pre-operative and post-operative phases of the study with 22 out of 40 subjects experiencing nausea or vomiting overall. Perphenazine, 2.5 mg, showed no useful anti-emetic effect. Both anti-emetics increased the soporific effect of premedication at the 90-min interval. Subjects receiving perphenazine experienced significantly more dizziness than those of other groups.

Azepines↗
PubMed1986

Aspirin and probenecid pretreatment influences the potency of thiopentone and the onset of action of midazolam.

The effects of pretreatment with aspirin and probenecid, two drugs which are highly bound to albumin, on an induction dose of thiopentone and time to onset of action of a fixed dose of midazolam were investigated. Both drugs significantly potentiate thiopentone and shorten the induction time with midazolam. The importance of individual variations in plasma proteins in influencing the action of highly bound drugs is stressed.

Adult↗