Canadian Anaesthetists' Society journal
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Clinical Trial Controlled Clinical Trial
Esmolol for control of increases in heart rate and blood pressure during tracheal intubation after thiopentone and succinylcholine.
Esmolol, an ultra-short-acting cardioselective beta-adrenergic blocker, was investigated in a double-blind prospective protocol for its ability to control haemodynamic responses associated with tracheal intubation after thiopentone and succinylcholine. Thirty ASA physical status I patients received a 12-minute infusion of esmolol (500 micrograms X kg-1 X min-1 for four minutes, then 300 micrograms X kg-1 X min-1 for 8 minutes) or saline. Five minutes after the start of the drug/placebo infusion, anaesthesia was induced with 4 mg X kg-1 thiopentone followed by succinylcholine for tracheal intubation. ⋯ Increases in HR, SAP and RPP after intubation were approximately 50 per cent less in patients given esmolol compared to patients given placebo. There were highly significant differences in HR (p less than 0.0001), and RPP (p less than 0.0005) and significant differences in SAP (p less than 0.05) when the maximal esmolol post-intubation response was compared to the maximal placebo response. Infusion of esmolol in the dose utilized in this study significantly attenuated but did not completely eliminate cardiovascular responses to intubation.
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Comparative Study
Contribution of muscle relaxant to the haemodynamic course of high-dose fentanyl anaesthesia: a comparison of pancuronium, vecuronium and atracurium.
To define the role of muscle relaxants in haemodynamic responses to high-dose (75 micrograms X kg-1) fentanyl anaesthesia and to noxius stimuli associated with intubation and sternal spread during coronary artery bypass surgery, we compared haemodynamics between three groups of patients given either pancuronium (0.1 mg X kg-1, n = 11), vecuronium (0.086 mg X kg-1, n = 11) or atracurium (0.43 mg X kg-1, n = 12). Additional doses of the relaxants were given to maintain a 90 per cent neuromuscular block. Patients given pancuronium showed no increases in mean values of heart rate, arterial pressure or cardiac output during the induction of anaesthesia or after intubation, whereas a decrease in these variables was observed in the vecuronium group. ⋯ Patients given atracurium had a small increase in pulmonary vascular resistance during sternotomy. Our patients continued their beta-adrenergic antagonist medication until the morning of the day of operation and they were pretreated with a small intravenous dose of diazepam (0.1 mg X kg-1) before induction of anaesthesia. These drugs may have prevented the deleterious haemodynamic effects observed by some investigators after the administration of pancuronium during high-dose fentanyl anaesthesia.
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Three cases of trismus caused by oropharyngeal sepsis are described where fibreoptic-assisted awake intubation using an oral airway intubator and nebulised lidocaine was safely and successfully achieved.
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A case report is presented describing the clinical usefulness of transcutaneous oxygen (PtcO2) monitoring in an infant undergoing tracheoesophageal fistula repair. Its use allowed early and precise recognition of hypoxaemia during periods of surgical manipulation. During periods of hypoxaemia, there were no associated cardiovascular changes or changes in routine monitoring modalities. Clinical use of PtcO2 may detect early hypoxaemia and thus allow for correction before the appearance of changes in vital signs.
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An episode of malignant hyperthermia occurring in a two-year-old child undergoing cardiac surgery is reported. The coincidental usage of hypothermic cardiopulmonary bypass obscured the classical presenting signs and symptoms of the syndrome. Once the clinical diagnosis was confirmed, rapid reversal was achieved with the administration of dantrolene sodium.