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Biomedical subjects

D B Scott

Publications and source records attributed to D B Scott.

At least 145 records · Page 8Linked to original sources
PubMed1975

Evaluation of the toxicity of local anaesthetic agents in man.

Etidocaine given by intravenous infusion has been compared, using a double-blind technique, with bupivacaine and lignocaine in respect of toxic symptoms and signs. The degree of toxicity is affected considerably by the rate of drug infusion. At 10 mg/min subjects could tolerate twice the dose of etidocaine as bupivacaine. Tolerance to etidocaine was less at 20 mg/min but still compared favourably with bupivacaine at 10 mg/min. Considering the difference in potency of the two agents it was considered that the therapeutic ratios would not be substantially different. Lignocaine at 20 mg/min was better tolerated than etidocaine. Venous plasma concentration during these experiments showed a more rapid decrease in the case of etidocaine compared with bupivacaine, but the concentrations were unhelpful in predicting the toxic effects. Similarly electroencephalography revealed no abnormalities in spite of marked subjective and objective signs of toxicity.

Acetanilides↗
PubMed1975

Evaluation of etidocaine in extradural block.

Etidocaine has been evaluated in extradural block with regard to its absorption, toxicity and clinical effectiveness, which have been compared with those of bupivacaine. Etidocaine is associated with lower plasma concentrations than bupivacaine and its absorption is decreased by the addition of adrenaline 1:200,000 to a greater extent than is the case with bupivacaine. Etidocaine causes motor paralysis more frequently than does bupivacaine, especially if adrenaline is added. The duration of action of the two drugs is similar when comparing etidocaine 1% and bupivacaine 0.5%. Bupivacaine 0.75%, however, acts for a significantly longer time than etidocaine 1%. The drug is a useful addition to the range of local anaesthetics, especially with regard to the degree of motor blockade it can achieve during surgical procedures.

Acetanilides↗
PubMed1975

Evaluation of clinical tolerance of local anaesthetic agents.

The clinical tolerance to local anaesthetic drugs can be assessed from a knowledge of their pharmacokinetic behaviour, their absorption properties and the effects produced by controlled i.v. infusions. Pharmacokinetic behavior can be calculated from the plasma concentrations of the drugs injected i.v. in non-toxic doses. Absorption properties can likewise be determined from plasma concentrations following injection at various sites. Acute toxicity can be assessed by i.v. infusion of toxic doses into volunteers. The dosage required to produce symptoms can be compared with other drugs. Such dosage is considerably affected by the rate of injection. The venous plasma concentrations at the height of toxicity are unreliable guides to toxicity. Experiences using the new local anaesthetic etidocaine are reported.

Absorption↗
PubMed1975

An outbreak of ringworm in karakul sheep caused by a physiological variant of Trichophyton verrucosum Bodin.

An outbreak of ringworm in Karakul sheep occurred during 1973 among the flocks of at least 14 farmers in South West Africa and the northern Cape Province. Infections spread from one farm to another as a result of introducing infected stud rams. On one farm a few cattle, a goat and a horse developed lesions after being in contact with infected sheep. Some of the attendants handling infected sheep also contracted the disease. Strains recovered from infected animals resembled Trichophyton verrucosum morphologically, but when grown on laboratory media they did not require an exogenous source of vitamins, which was found to be indispensable for strains of this species studied previously.

Africa, Southern↗
PubMed1974

Effects of posture on limb blood flow in late pregnancy.

Arm and leg blood flow was measured in 40 patients in late pregnancy in the supine and left lateral positions, and the changes were contrasted with changes found in 15 patients investigated in the early puerperium. A significant reduction in leg flow occurred in the pregnant subjects when the supine position was assumed. A further 30 patients in late pregnancy had leg flow measured in the following positions: left lateral, supine, right lateral, and the two mid-positions. Leg flow significantly increased on moving from the supine to all other positions except the right intermediate position, indicating that a leftward tilt is more effective in preventing caval compression.

Arm↗
PubMed1973

Modification of plasma corticosteroid concentrations during and after surgery by epidural blockade.

The adrenocortical response to major surgery was assessed by the measurement of plasma corticosteroid concentrations in patients receiving either a general anaesthetic alone or in combination with an epidural block. The expected increase in plasma corticosteroid concentration seen in the general anaesthesia group was significantly inhibited by epidural block. The inhibition was related to the duration of the epidural block. The lack of the normal adrenocortical response to surgery was not associated with cardiovascular collapse and indeed did not seem detrimental in any way. These findings question the need for corticosteroid "cover" for the stress of surgery in patients who have been taking corticosteroid drugs.

Adrenal Cortex Hormones↗