British journal of anaesthesia
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We have used continuous ambulatory electrocardiography in the perioperative period to monitor 108 patients with known cardiovascular disease undergoing non-cardiac surgery. There was a high incidence of ischaemic ST segment changes and ventricular arrhythmias. ⋯ However, the mean duration of ischaemic ST segment changes was increased significantly in those patients with treated hypertension. Of the risk factors considered, preoperative ischaemia and peroperative systolic arterial pressure were significant correlates with postoperative myocardial ischaemia.
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We have studied the effects of extradural anaesthesia with bupivacaine (plain) in eight healthy parturients undergoing elective Caesarean section, on blood flow in maternal uterine and placental arcuate arteries and in fetal umbilical, renal and middle cerebral arteries, using a colour Doppler technique. Simultaneously, fetal myocardial function was investigated by M-mode echocardiography. ⋯ We found no changes in fetal myocardial function with extradural anaesthesia, except for an increase in the right ventricular inner end-diastolic dimensions. These results suggest that extradural anaesthesia has no detrimental effects on uteroplacental and fetal circulations in the uncomplicated pregnancy when maternal hypotension is avoided with rapid prehydration.
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Randomized Controlled Trial Clinical Trial
Clonidine does not delay recovery from anaesthesia.
Clonidine is known to reduce anaesthetic requirements and improve haemodynamic stability when given as premedication. This study, of 46 ASA I-II patients undergoing thyroid surgery, was designed to assess if clonidine interferes with recovery from anaesthesia. Patients were allocated randomly to three groups to receive, 2 h before surgery, flunitrazepam 1 mg, clonidine 150 micrograms, or both drugs. ⋯ Psychomotor performance was decreased significantly after operation in the three groups (P less than 0.05) and returned to baseline at 240 min. There was no significant difference between the three groups. This study indicates that clonidine 150 micrograms orally before surgery does not delay recovery from anaesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Accuracy of placement of extradural needles in the L3-4 interspace: comparison of two methods of identifying L4.
The certainty with which the L3-4 vertebral interspace can be identified was investigated by studying 50 cadavers. These were allocated randomly to two groups, differing in the way in which the L4 spinous process was identified. Identification of L4 by physically constructing Tuffier's line on the subject led to an increase in the number of catheters sited at the correct level (P less than 0.01).
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Randomized Controlled Trial Clinical Trial
Effects of trimetaphan on the cardiovascular response to tracheal intubation.
In three groups of 10 patients, we have studied the effect on the cardiovascular responses to laryngoscopy and intubation of bolus doses of saline or trimetaphan 0.05 mg kg-1 or 0.1 mg kg-1 given 1.75 min before the start of laryngoscopy. Anaesthesia was induced with thiopentone 5 mg kg-1 i.v. and tracheal intubation was facilitated with vecuronium 0.2 mg kg-1. During anaesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. ⋯ These increases following tracheal intubation were less in trimetaphan-treated patients compared with those of the control group (P less than 0.05). There was no significant difference in heart rate following tracheal intubation between the three groups. These data suggest that trimetaphan may be used as a supplement during induction, to attenuate the hypertensive response associated with laryngoscopy and tracheal intubation.