British journal of anaesthesia
-
The interactions of four anaesthetic drugs (ketamine, propanidid, Althesin and methohexitone) with two neuromuscular blocking agents (suxamethonium and pancuronium) have been investigated. On the isolated rat phrenic nerve-diaphragm preparation, all the anaesthetic drugs examined potentiated suxamethonium more than they potentiated pancuronium. ⋯ With the exception of Althesin, all the anaesthetics decreased the sensitivity of the frog rectus preparation to acetylcholine. The possible sites and mechanisms of these interactions are discussed.
-
The effects of sodium thiopentone 19-757 mumol/litre, sodium pentobarbitone 25-806 mumol/litre, propanidid 74-1186 mumol/litre, Althesin 55-220 mumol/litre, diazepam 17.6-140 mumol/litre and ketamine 1.8-116.8 mumol/litre on the time-course of miniature end-plate currents of the excised mouse diaphragm were investigated. The currents were detected by means of extracellular electrodes and recorded with a transient recorder. ⋯ This reduction in the duration of end-plate currents reduced the amplitude of postsynaptic potentials. A similar effect at central synapses may account for a failure of synaptic transmission caused by anaesthetic drugs and it is suggested that a reduction in the lifetime of open postsynaptic ionic channels is a common action of anaesthetic drugs.
-
Comparative Study Clinical Trial Controlled Clinical Trial
Glycopyrrolate-neostigmine mixture for antagonism of neuromuscular block: comparison with atropine-neostigmine mixture.
Glycopyrrolate, a new anticholinergic agent, was evaluated and compared with atropine. Glycopyrrolate 0.2 mg to neostigmine 1.0 mg was found to be safe and effective. The heart rates remained more stable with glycopyrrolate, and the frequency of arrhythmia, which was both transient and of no consequence, was similar in the two groups. The antisialogogue action of glycopyrrolate was superior to that of atropine.
-
All halothane vaporizers tested for leakage when turned off, leaked significant amounts of halothane and this may represent a hazard to patients liable to develop halothane hepatitis or malignant hyperpyrexia. The hazard from leaking vaporizers may be reduced considerably by the use of well-designed bypass units. ⋯ The hazard from contamined rubber or plastic components of the anaesthetic machine can be eliminated only by using one apparatus without the vaporizers having been attached at any time during its working life. Similarly, hazards may arise from trichloroethylene vaporizers and from circuit components contaminated with trichloroethylene.