Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jul 1991
Randomized Controlled Trial Comparative Study Clinical Trial Controlled Clinical TrialEffects of glycopyrrolate and atropine on heart rate variability.
Analysis of heart rate variability, combined with physiological tests (deep breathing and tilt tests) was used to characterise the effects of atropine and glycopyrrolate on the parasympathetic nervous tone of the heart in healthy male volunteers. The low dose of atropine (120 micrograms) administered as a continuous infusion in 15 min was associated with parasympatomimetic effects estimated by the slowing of the heart rate and an increase of the mean and beat-to-beat heart rate variability. ⋯ The higher doses of atropine (720 micrograms) and glycopyrrolate (300 micrograms) administered as a continuous infusion in 15 min produced an equal vagal cardiac blockade characterised by significant tachycardia and a decrease in overall and beat-to-beat heart rate variability. It is concluded that at low doses the parasympatomimetic action of glycopyrrolate is less marked than that of atropine; and at higher doses only small differences exist between these two muscarinic antagonists in their effects on cardiac vagal outflow, assessed by heart rate and heart rate variability.
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Acta Anaesthesiol Scand · Jul 1991
Randomized Controlled Trial Comparative Study Clinical TrialSplit-dose atropine versus glycopyrrolate with neostigmine for reversal of gallamine-induced neuromuscular blockade.
The effects of a split-dose of atropine sulphate versus a single dose of glycopyrrolate given with neostigmine for the reversal of gallamine-induced neuromuscular blockade were studied in 55 patients undergoing gynaecological surgery. The patients were randomized to receive either a single dose of glycopyrrolate (7 micrograms.kg-1) or two doses of atropine (8 micrograms.kg-1 each), given with an interval of 1 min. ⋯ It is concluded that a split-dose of atropine has similar chronotropic effects to a single dose of glycopyrrolate for the reversal of gallamine-induced neuromuscular blockade. However, the finding of a higher incidence of cardiac arrhythmias in the atropine group suggests that this reversal regime should be reserved for patients without cardiac disease.
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Acta Anaesthesiol Scand · Jul 1991
Randomized Controlled Trial Comparative Study Clinical TrialHemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation.
To study the relationship between the intensity of the stimulus exerted against the base of the tongue during direct laryngoscopy and the magnitude of associated hemodynamic and catecholamine responses, a study was conducted in 40 ASA I or II patients. Laryngoscopy lasting 40 s was performed with a size 3 Macintosh blade connected to a force-displacement transducer. The intensity of the stimulus exerted during laryngoscopy is expressed by the product of its average force (N) and duration (s) and given as impulse in Ns. ⋯ The mechanisms of the responses to laryngoscopy and orotracheal intubation are proposed to be by somato-visceral reflexes. Stimulation of proprioceptors at the base of the tongue during laryngoscopy induces impulse-dependent increases of systemic blood pressure, heart rate and plasma catecholamine concentrations. Subsequent orotracheal intubation recruits additional receptors that elicit augmented hemodynamic and epinephrine responses as well as some vagal inhibition of the heart.
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Acta Anaesthesiol Scand · Jul 1991
The effect of peripheral hypothermia on a vecuronium-induced neuromuscular block.
Seven healthy patients were investigated during midazolam-fentanyl nitrous oxide-oxygen anaesthesia. The mechanical twitch response of the adductor pollicis muscle was recorded simultaneously during bilateral supramaximal train-of-four (TOF) stimulation of the ulnar nerves at the wrist. Intense neuromuscular block was evaluated using the post-tetanic count (PTC) method. ⋯ In the normothermic arm a close correlation was found between the number of post-tetanic twitches and the time to first response to TOF stimulation. In contrast, in the hypothermic arm the number of post-tetanic twitches showed great variation with a poor correlation to the duration of intense neuromuscular block. It is concluded that the time course of action of a vecuronium-induced neuromuscular block is markedly prolonged during peripheral hypothermia and intense neuromuscular block cannot reliably be assessed using the PTC method at low peripheral temperature.(ABSTRACT TRUNCATED AT 250 WORDS)
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Acta Anaesthesiol Scand · Jul 1991
Comment Letter Historical ArticleForty-six "first anaesthetics" in the world.