Anaesthesia
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Randomized Controlled Trial Clinical Trial
Propofol: clinical strategies for preventing the pain of injection.
Eight modes of administration of propofol were assessed in order to minimise the pain of injection. An intravenous bolus injection in the antecubital fossa was the only approach that caused no pain. ⋯ Slowing the speed of injection caused the greatest discomfort. An indirect biochemical mechanism for the pain is proposed.
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Randomized Controlled Trial Clinical Trial
Nifedipine prevents the pressor response to laryngoscopy and tracheal intubation in patients with coronary artery disease.
The efficacy of sublingual nifedipine, administered one minute before anaesthetic induction, in order to minimise the pressor response to laryngoscopy and tracheal intubation was studied in a group of 15 patients who underwent coronary artery bypass surgery. Another group of 15 similar patients served as control. Premedication consisted of oral diazepam 5-10 mg, intramuscular morphine 0.2 mg/kg and promethazine 0.4 mg/kg. ⋯ This increase was absent in the patients pretreated with nifedipine. The nifedipine group also maintained a lower rate-pressure-product than the control group during the period of study. It is concluded that nifedipine 10 mg is a useful pretreatment to prevent the pressor response to laryngoscopy and tracheal intubation in patients with coronary artery disease.
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Plasma lignocaine levels were measured at 5, 10 and 15 minutes following local application (4 mg/kg) to the upper airway in children who underwent endoscopy under general anaesthesia. These levels were then correlated with the appearance of the moistness of the airway mucosa secondary to premedication with atropine. ⋯ Significantly higher (p less than 0.05) plasma levels of lignocaine were achieved when the mucosa was 'very dry' especially in children under 2 years of age. The total dose of lignocaine applied to the upper airway of children should probably be reduced, in the presence of a 'dry' mucosa after effective antisialogogue premedication, and especially when less than 2 years of age.
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Randomized Controlled Trial Clinical Trial
Reversal of pancuronium. Neuromuscular and cardiovascular effects of a mixture of neostigmine and glycopyrronium.
Moderate to deep (67-99% single twitch depression) pancuronium-induced neuromuscular blockade was antagonised with neostigmine (30 micrograms/kg, 60 micrograms/kg, or 80 micrograms/kg) in combination with glycopyrronium. Twenty-seven patients were reversed from 91%-99% twitch depression. Recovery of the first twitch of a train-of-four to 95% of control twitch took at least 20 minutes with neostigmine 30 micrograms/kg. ⋯ Heart rates after reversal decreased gradually in all groups, although the decrease was initially greater in the low dose neostigmine (30 micrograms/kg) group. A fixed 5:1 ratio of neostigmine and glycopyrronium will usually antagonise a moderate (70%-80%) pancuronium block to a train of four of greater than 75% within 12.5 minutes if at least 60 micrograms/kg of neostigmine is administered. More than 30 minutes may be required for reversal whatever the dose of neostigmine, for antagonism from greater than 90% twitch depression.
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Randomized Controlled Trial Clinical Trial
Effects of beta-adrenoceptor antagonism on the cardiovascular and catecholamine responses to tracheal intubation.
The catecholamine and cardiovascular responses to laryngoscopy and tracheal intubation were studied in 20 patients who underwent elective gynaecological surgery and who were allocated randomly to receive either practolol 10 mg or saline intravenously prior to induction of anaesthesia. Anaesthesia was induced with fentanyl and thiopentone; atracurium was administered and the lungs were ventilated artificially with 67% nitrous oxide in oxygen. Tracheal intubation was performed when muscle relaxation was adequate. ⋯ A significant increase in catecholamine concentrations occurred in both groups in response to tracheal intubation but the magnitude of the increase in adrenaline was greater in the practolol group. There were no significant differences in arterial pressure or heart rate changes between the groups. We conclude that pretreatment with practolol is of no value in the attenuation of the hypertensive response to direct laryngoscopy and tracheal intubation in previously normotensive patients.