Journal of anesthesia
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Journal of anesthesia · Dec 1995
Difference of train-of-four fade induced by nondepolarizing neuromuscular blocking drugs: a theoretical consideration on the underlying mechanisms.
Nondepolarizing neuromuscular blocking drugs induce train-of-four (TOF) fade, i.e., the reduction of the fourth to the first twitch height in a train under TOF stimulation. It has been observed that the degree of TOF fade varies with the drug used and is inversely correlated with the potencies of the drug. ⋯ The model was based on the following assumptions: (1) Twitch response is evoked by the binding of acetylcholine (ACh) molecules to the postsynaptic nicotinic receptors in a neuromuscular junction, (2) time-dependent ACh mobilization in a motor nerve terminal results in less ACh output at the fourth stimulus in a train than at the first stimulus, (3) the drugs compete with ACh for the postsynaptic receptors and inhibit the receptor-binding of ACh, and (4) the drugs have various affinities for the receptors. This study suggested that the difference of affinities of the drugs for postsynaptic ACh receptors may cause the difference of TOF fade.
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Journal of anesthesia · Dec 1995
Inhibitory effect of prostaglandin E1 on gastric secretion during general anesthesia in humans.
The present study was undertaken to clarify the effects of prostaglandin E1 (PGE1) on gastric secretion during general anesthesia. Thirty-three patients, 16 with (PGE1 group) and 17 without (control group) PGE1 administration, scheduled for selective surgery were studied during general anesthesia with nitrous oxide (67%) and enflurane (1%-2% inspired). PGE1 was administered at a rate of 50-200 ng·kg(-1)·min(-1) when hypotensive medication was required. ⋯ The pH of gastric juice increased significantly, and the acidity and pepsin activity decreased after the beginning of the administration of PGE1, and these changes were observed even 1h after discontinuation. There was significant differences in the pH, acidity, and pepsin activity between the two groups after administration of PGE1. The results indicate that PGE1 inhibits gastric secretion at doses that produce a sufficient hypotensive effect under general anesthesia.