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Biomedical subjects

A D Nicholas

Publications and source records attributed to A D Nicholas.

11 recordsLinked to original sources
PubMed1988

Comparison of atracurium and vecuronium during anaesthesia for laparoscopy.

Atracurium 0.3 mg kg-1 and vecuronium 0.06 mg kg-1 were compared directly in a double-blind randomized trial during anaesthesia for laparoscopy in 57 healthy young women. The effects of the drugs were monitored using a portable electromyograph. Both drugs provided adequate intubating conditions at 3 min, and prompt antagonism of paralysis after administration of neostigmine, but recovery was significantly faster with vecuronium (mean time to 20% recovery of control electromyographic response: vecuronium 15.1 min; atracurium 20.6 min (P less than 0.001)). Atracurium caused a higher frequency of clinically observed allergoid reactions (21%) compared with vecuronium (3%).

Adult↗
PubMed1982

Double-blind comparison of meptazinol and pethidine in labour.

The analgesic efficacy and safety of intramuscular meptazinol and pethidine in the first stage of labour were compared in a randomized double-blind trial in 358 patients. Pain relief was measured on a verbal rating scale, maternal side effects were recorded and neonatal outcome assessed in the first 24 h. Pain relief during the first hour after injection was significantly greater in the meptazinol than in the pethidine group at 45 and 60 min. Thereafter, there was no difference between the treatments, and the duration of action was approximately the same. Twenty-eight per cent of patients experienced side effects after meptazinol compared with 35% after pethidine. The commonest were nausea and vomiting with a similar incidence in both groups. Most of the neonatal observations revealed no difference between the two drugs, but significantly more babies whose mothers had received meptazinol had an Apgar score of greater than or equal to 8 at 1 min after birth.

Anesthesia, Obstetrical↗
PubMed1980

Pathophysiology of inner ear dysfunction in the squirrel monkey in rapid decompression.

More than 90 squirrel monkeys with bilateral myringotomies (a small hole in each ear drum) were rapidly decompressed in a hyperbaric chamber according to a special diving profile in which 35% of attempts produced disorders ("hits") confined to the inner ear. Monkeys receiving inner ear hits (as determined by the sudden onset of vigorous head or eye nystagmus during decompression) were tested and killed at times ranging from 1 h to more than 12 mo following the dive. Histologically, in monkeys killed 1 mo or less after the hit, hemorrhage and/or a deep purple-staining precipitated material were frequently found in the otic fluid spaces. In those monkeys killed more than 1 mo after a hit, ectopic new bone growth in the arms of the semicircular canals was a common sequela. New bone growth never appeared in the cochlea. In unaffected ears, and in both ears of control animals, the precipitated material was somewhat less than in ears damaged by decompression; and, furthermore, new bone growth did not occur. Behaviorally, the hit monkeys showed vestibular deficits that were consistent with the structural damage revealed by histology.

Animals↗
PubMed1976

Intradermal study of a new local anaesthetic agent aptocaine.

In a double-blind trial in 28 human volunteers, a new local anaesthetic agent, aptocaine, was compared intradermally at 1, 2 and 3% concentrations with lignocaine 2% and bupivacaine 0.5%. In a second trial in 27 subjects, 1% aptocaine was compared with mepivacaine and prilocaine, both 1, 2 and 3%. In terms of activity as determined by area of anaesthesia, and of duration of action, aptocaine was similar to mepivacaine and more active and long-lasting than lignocaine and prilocaine. By this route aptocaine also appeared longer-lasting than bupivacaine. Duration of action was unaffected by concentration. Aptocaine had marked vasoconstrictor activity, which was maximal at 1%. These local anaesthetic properties suggest that aptocaine merits clinical trials, especially in dentistry.

Adult↗
PubMed1975

Epidural analgesia, fetal monitoring and the condition of the baby at birth with breech presentation.

Between December 1970 and March 1973, 138 patients with a singleton fetus presenting by the breech after 36 weeks of pregnancy were deemed suitable for vaginal delivery under epidural analgesia; 130 were delivered vaginally, 10 of them by breech extraction. There was one stillbirth and no neonatal deaths. Epidural analgesia for vaginal breech delivery seemed beneficial. In 65 cases it was possible to compare the umbilical vein pH with the Apgar score at one minute. In 35 patients a continuous recording of the fetal heart rate was used to predict the Apgar score at one minute and the results are discussed.

Anesthesia, Epidural↗
PubMed1974

Bupivacaine carbonate and bupivacaine hydrochloride: a comparison of blood concentrations during epidural blockade for vaginal surgery.

Carbonated bupivacaine, plain bupivacaine hydrochloride, and bupivacaine hydrochloride with adrenaline were used to provide epidural analgesia for patients undergoing vaginal hysterectomy. Following injection to the blood concentrations of bupivacaine were measured at intervals over a period of 30 minutes. All three preparations produced satisfactory analgesia at a bupivacaine dose of 1.5 mg/kg body weight. The highest group mean blood concentrations were just outside the toxic dose range. Carbonated bupivacaine was absorbed most rapidly producing significantly higher blood concentrations up to 12 minutes after injection.

Age Factors↗