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Biomedical subjects

D B Scott

Publications and source records attributed to D B Scott.

At least 91 records · Page 5Linked to original sources
PubMed1982

Effect of the trendelenberg position on spinal anaesthesia with hyperbaric bupivacaine.

In a double-blind study, the effect of the Trendelenberg position was compared with the supine, in 20 patients following intrathecal injection of 3 ml of 0.5% bupivacaine in 8% glucose. All patients had blocks suitable for abdominal surgery. Although the mean spread was greater in those patients titled head-down, this was not statistically significant. The variation of the spread around the mean was greater in the head-down group, and blocks extended into the cervical region in two patients. There were no differences in motor block, duration or cardiovascular changes between the groups. It is concluded that the trendelenberg position is not necessary to ensure spread of local anaesthetic solution into the mid thoracic region for abdominal surgery.

Adult↗
PubMed1982

The use of labetalol in anaesthesia.

1 Observed and possible roles for the use of labetalol in anaesthesia are reviewed. 2 When used together with halothane inhalation anaesthesia, satisfactory conditions are achieved for safe hypotensive anaesthesia: (a) Labetalol and halothane have additive hypotensive effects. (b) The usual dose of labetalol is 25 mg intravenously together with 1% halothane. (c) The duration of hypotension can be controlled in the presence of halothane; withdrawal leads to rapid recovery of pre-surgery blood pressure. (d) High doses of halothane (3%) with labetalol predispose to the myocardial depressant effects of halothane and undesirable reductions in myocardial performance. 3 As it is now seen to be important to reduce the blood pressure before anaesthesia and surgery in hypertensive patients, then labetalol is likely to be satisfactory either by the intravenous route for immediate reduction or for less urgent reduction of raised arterial pressure by the oral route. 4 It is known that anaesthesia (for example, laryngoscopy) and surgery provoke hypertensive responses which are particularly undesirable in the patient with pre-existent myocardial ischaemia. In such cases it is likely that previous treatment with labetalol will satisfactorily modify unwanted hypertensive and cardiovascular responses.

Anesthesia↗
PubMed1982

Identification and mobilization by cointegrate formation of a nodulation plasmid in Rhizobium trifolii.

A nodulation plasmid, pRtr-514a, of molecular size 180 megadaltons (Mdal) was identified in Rhizobium trifolii strain NZP514. This plasmid was absent in both spontaneous and heat-cured Nod- derivatives of NZP514, and these strains were unable to induce root hair curling. The ability to nodulate clover was transferred from the wild-type strain to a Nod- derivatives, PN104, with the broad-host-range plasmid R68.45 (39 megadaltons) at a cotransfer frequency of about 4 X 10(-3). Most of the Nod+ transconjugants were resistant to kanamycin, tetracycline, and carbenicillin and had received a plasmid approximately 36 or 70 Mdal larger than pRtr514a but did not contain a plasmid of the size of R68.45, indicating that pRtr-514a was mobilized as a cointegrate plasmid containing either one or possibly two copies of R68.45. Use of these cointegrate-containing strains as donors in further crosses with the Nod- derivative strain PN118 resulted in high-frequency transfer of Nod+ (10(-3) to 10(-4), with cotransfer frequencies with kanamycin of up to 100%. Introduction of R68.45 into a derivative of NZP514 containing the broad-host-range plasmid pJP4 (52 Mdal) resulted in a high frequency of transconjugants carrying a cointegrate plasmid composed of pRtr-514a and pJP4. When used as donors to Nod- derivatives, such strains cotransferred Nod+ with kanamycin plus mercury at a frequency of 67%. The identification of stable cointegrates between pRtr-514a and the broad-host-range plasmids R68.45 and pJP4 should enable several genetic manipulations to be carried out with this nodulation plasmid, including the transfer of the plasmid to most gram-negative bacterial genera.

Anti-Bacterial Agents↗
PubMed1982

Spinal anesthesia with hyperbaric bupivacaine: effect of added vasoconstrictors.

The effect of adding 0.2 ml of 1:1000 epinephrine or 0.5 ml of 1% phenylephrine to 3 ml of 0.5% bupivacaine in 8% dextrose for spinal anesthesia was assessed in 30 patients in a double-blind study. The addition of phenylephrine gave a small prolongation of the block which was not statistically significant. Although epinephrine produced a greater prolongation, this only reached statistical significance with regard to total duration. Three patients who received solutions that contained a vasopressor had prolonged blocks, but these solutions could not be relied upon to produce consistently a clinically significant increase in duration in individual patients.

Aged↗
PubMed1981

Effects of posture on the spread of isobaric and hyperbaric amethocaine.

The effects of posture on the spread of isobaric and hyperbaric amethocaine were studied after intrathecal injection in 60 patients. Gravity had no effect on the spread of isobaric solutions and, while hyperbaric solutions did spread under the effect of gravity, it was found that posture could not be used to control spread effectively. The results also show that the dose of local anaesthetic injected had a more important effect on the duration of blockade than on the spread.

Anesthesia, Spinal↗
PubMed1981

Effect of baricity on spinal anaesthesia with bupivacaine.

In a double-blind study of spinal anaesthesia with 0.5% bupivacaine 3 ml with no glucose, 5% glucose or 8% glucose all three solutions gave consistently good nerve blocks. The hyperbaric solutions (5% and 8% glucose) produced a greater cephalad spread and were suitable for lower abdominal surgery, whereas the plain solution (no glucose) seldom affected the thoracic nerves. Cardiovascular changes were more marked with the hyperbaric solutions but only necessitated treatment on two occasions. The duration of block was not affected by baricity and was in the range 140-160 min.

Adolescent↗
PubMed1981

Extradural morphine for pain after surgery.

The effects of 10 mg of morphine sulphate given either extradurally or i.m. for the relief of pain after operation were compared in two randomized double-blind trials in patients undergoing major gynaecological surgery. In the first trial when morphine was given with the local anaesthetic before surgery, extradural administration resulted in significantly longer lasting analgesia: mean 707 min compared with 371 min (i.m.). In the second trial in patients complaining of pain after operation, extradural morphine had a slower onset of action, but longer duration of action compared with i.m. morphine, although the differences were not statistically significant. In this group extradural morphine often failed to provide useful analgesia. The extradural group received significantly less additional morphine (6.75 mg) than did the i.m. group (18.75 mg) in the following 24 h.

Adult↗
PubMed1981

Effect of added epinephrine on spinal anesthesia with lidocaine.

The effect of adding 0.1, 0.2, or 0.3 ml of 1:1000 epinephrine to 1.5 ml of 5% lidocaine in 7.5% dextrose for spinal anesthesia was assessed in 40 patients in a double-blind study. The addition of epinephrine produced little or no clinically useful prolongation of block. There was a small reduction in the speed of decay of nerve block, but this only reached statistical significance with regard to total recovery, which took 40 to 50 minutes longer with the epinephrine-containing solutions. No difference could be seen between the three doses of epinephrine.

Aged↗
PubMed1980

Effects of concentration of local anaesthetic drugs in extradural block.

An increase in the concentration of bupivacaine from 0.5% to 0.75% and etidocaine from 1.0% to 1.5% for extradural block resulted in a more rapid onset of sensory analgesia and motor blockade, a greater frequency of adequate analgesia,a greater depth of motor block and a longer duration of sensory analgesia and motor blockade. An increase in the concentration of prilocaine from 2% to 3% failed to reveal any significant advantage. The use of the more concentrated solutions of bupivacaine and etidocaine would appear to afford significant clinical advantages in extradural anaesthesia for surgery.

Acetanilides↗
PubMed1980

Comparison of carbonated bupivacaine and bupivacaine hydrochloride for extradural anaesthesia.

A double-blind comparison of carbonated bupivacaine and bupivacaine hydrochloride in extradural anaesthesia was performed in 40 patients. No significant differences in the onset times, sensory blockade, motor blockade and duration of anaesthesia were demonstrated. Carbonated bupivacaine does not appear to offer any advantage over the hydrochloride salt for extradural anaesthesia.

Adult↗
PubMed1980

Prolonged infusion of chlormethiazole in intensive care.

Chlormethiazole has proved useful for prolonged sedation in patients receiving artificial ventilation of the lungs during intensive care. In short-term infusions sedation and unconsciousness can be produced quickly and reversal is rapid on stopping the administration. After prolonged infusion, however, recovery is much slower because of accumulation of the drug. The pharmacokinetics of chlormethiazole in both short and prolonged infusions were studied in four patients. Following brief administrations the drug disappeared very quickly from the blood as a result of re-distribution and the patients wakened after a few minutes. Unconsciousness was associated with plasma concentrations in the range of 3--5 micrograms ml-1. After 48 h administration, recovery was much slower, the elimination half-life varying from 3.5 to 12.1 h.

Adolescent↗