Articles: anesthetics.
-
Clinical pediatrics · Oct 1988
Half-strength TAC topical anesthetic. For selected dermal lacerations.
A prospective evaluation of 75 consecutive children with lacerations of the face, lip, and scalp who received TAC (tetracaine, epinephrine [adrenalin], cocaine) topical anesthetic for the repair of their wound was performed. The TAC preparation contained one-half the conventional concentration of cocaine (5.9%) and tetracaine (0.25%) previously used in other studies that have evaluated its anesthetic efficacy. A maximal dosage of 3 ml of TAC (containing 175 mg cocaine and 7.5 mg tetracaine) was applied to each laceration. ⋯ No adverse reactions were noted in any patient who received TAC, and in no instance did a complication of wound healing occur. The original formulation of TAC was arbitrarily composed, and the maximum concentration per dosage of the potentially toxic component medications of TAC that can be "safely" applied to dermal lacerations in children remains to be defined. Utilization of this diluted preparation will diminish the risk of potential systemic toxicity from the absorbed component medications of TAC without compromising anesthetic efficacy.
-
Twenty-two anaesthetists participated in a study to assess the influence of occupational exposure to anaesthetic agents on mood (arousal and stress) and cognitive functions. In a cross-over design, each anaesthetist worked one day in a reference facility (for example, intensive care) and another day in a scavenged operating theatre where time-weighted exposure averaged nitrous oxide 58 p.p.m. and halothane 1.4 p.p.m. The results showed that arousal scores reached a peak in the middle of the theatre day, but this appeared to reflect the nature of operating theatre work rather than exposure. ⋯ Similarly, there was no evidence that exposure impaired performance of tasks assessing syntactic and semantic reasoning, verbal and spatial memory, sensory-motor reaction time and attention. Performance in these tasks was, however, sensitive to the cognitive demands of the tasks and to naturally varying non-exposure factors. It is concluded that, compared with the reference condition, the concentrations of anaesthetic agents found in actively scavenged operating theatres have no detrimental effect on either the mood or the cognitive functions of anaesthetists.
-
Acta Anaesthesiol Scand · Oct 1988
Alterations in the pharmacokinetic properties of amide local anaesthetics following local anaesthetic induced convulsions.
The comparative pharmacokinetic properties of lidocaine, bupivacaine, etidocaine and mepivacaine were investigated in convulsing and non-convulsing dogs. The same dose of a given local anaesthetic was administered as either a 30-s intravenous (IV) bolus to produce convulsions or as a 15-min IV infusion producing no convulsions. Derived pharmacokinetic data were found to be different in convulsing and non-convulsing animals. ⋯ Overall, the most profound effects of convulsions on pharmacokinetic data were seen with mepivacaine. Convulsions were associated with increases in heart rate ranging from 117% (lidocaine, P less than 0.05) to 129% (mepivacaine, P less than 0.05), increases in cardiac output ranging from 78% (mepivacaine) to 232% (bupivacaine, P less than 0.05) and increases in mean arterial pressure ranging from 45% (lidocaine, P less than 0.05) to 80% (bupivacaine, P less than 0.05). The results suggest that when local anaesthetic-induced seizures occur in man, it cannot be assumed that these drugs will be distributed and eliminated as predicted by intravenous infusion of non-toxic doses.
-
Anaesthesia was induced with propofol 2.5 mg kg-1 followed by suxamethonium 1.5 mg kg-1 in six young healthy females undergoing laparoscopy. ECG was monitored continuously. ⋯ The bradycardia may be prevented by premedication with atropine. In contrast to thiopentone, propofol apparently lacks central vagolytic activity and may exert a central vagotonic effect which can exaggerate the muscarinic effects of suxamethonium.
-
The effects of methohexitone, ketamine, Althesin and droperidol on the peripheral vagal transmission to the heart were studied in decerebrate cats by evaluating the influences of the drugs on the heart rate responses to vagal electrostimulation and the injection of acetylcholine i.v. The sites of the peripheral vagal transmission (vagal ganglia and sino-atrial pacemaker cells) were reached by the application of the drugs to the pericardial space. The bradycardia in response to vagal electrostimulation was attenuated by Althesin (2.1 x 10(-4)-3.3 x 10(-3) mol litre-1; expressed as the concentration of alphaxalone), ketamine (2.9 x 10(-4)-4.6 x 10(-3) mol litre-1) and droperidol (2.6 x 10(-5)-6.6 x 10(-4) mol litre-1) in a concentration-dependent manner, but not influenced by methohexitone (2.8 x 10(-4)-4.4 x 10(-3) mol litre-1). The bradycardia-attenuating effects were probably caused by an atropine-like action since the heart rate responses to the injection of acetylcholine i.v. were also attenuated by the same three drugs.