Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 1997
Randomized Controlled Trial Comparative Study Clinical TrialLaryngeal mask insertion following inhalational induction in children: a comparison between halothane and sevoflurane.
The aim of this study was to compare laryngeal mask insertion conditions following inhalational induction with either halothane or sevoflurane. Fifty-eight healthy children scheduled for dental extraction were randomly assigned to receive nitrous oxide 66% in oxygen and 3.0 MAC of either halothane or sevoflurane introduced in a stepwise fashion. The laryngeal masks were inserted when an adequate depth of anaesthesia was attained and the reactions and time to insertion noted. ⋯ The conditions for laryngeal mask insertion were generally good with 86.2% and 89.2% in the halothane and sevoflurane groups respectively having had no reactions to insertion. The complications to laryngeal mask insertion encountered were mild. The emergence time from the anaesthetic was found to be shorter for sevoflurane but the difference was not statistically significant.
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Anaesth Intensive Care · Aug 1997
Randomized Controlled Trial Clinical TrialThe effect of supplemental oxygen on the incidence of hypoxaemia after premedication in patients undergoing cardiac surgery.
Opiate premedication may cause significant respiratory depression, particularly when other sedative agents such as scopolamine or benzodiazepines are added. This can cause hypoxaemia with potential for worsening myocardial ischaemia in cardiac surgery patients. The aim of this study was to investigate the incidence of hypoxaemia (SpO2 < 90%) in elective patients undergoing cardiac surgery and to assess the efficacy of supplemental oxygen in preventing it. ⋯ In patients receiving oxygen (n = 48) there were no episodes of hypoxaemia (0%). In patients not receiving oxygen (n = 46) there were 14 episodes of hypoxaemia (30%, P < 0.0001). We conclude that there is a significantly high incidence of hypoxaemia in cardiac surgery patients following combined opiate and sedative premedication and that it can be reduced by the routine administration of supplemental oxygen.
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Anaesth Intensive Care · Jun 1997
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialComparison of 0.5% ropivacaine and 0.5% bupivacaine in lumbar epidural anaesthesia for lower limb orthopaedic surgery.
The purpose of this study was to compare the epidural use of 0.5% ropivacaine and 0.5% bupivacaine in patients undergoing lower limb orthopaedic surgery. In a double-blind, randomized, multi-centre study involving 67 patients, thirty-two patients received 20 ml of 0.5% ropivacaine and 35 patients received 20 ml of 0.5% bupivacaine at the L2,3 or L3,4 interspace. Parameters measured were the onset time, duration and spread of sensory block, the onset time, duration and degree of motor block, the quality of anaesthesia and the heart rate and blood pressure profile during block onset. ⋯ In the bupivacaine group, motor and sensory block were judged to be satisfactory in 71% and 62% of patients respectively. Cardiovascular changes were similar in both groups. No statistical differences were found between the two groups regarding any of the study parameters.
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Anaesth Intensive Care · Jun 1997
Randomized Controlled Trial Comparative Study Clinical TrialAmrinone versus dobutamine in cardiac surgical patients with severe pulmonary hypertension after cardiopulmonary bypass: a prospective, randomized double-blinded trial.
We compared the relative effects of dobutamine (5 micrograms/kg/min) and amrinone (1.0 mg/kg bolus followed by 10 micrograms/kg/min) on right and left ventricular function and pulmonary arterial pressures during weaning from cardiopulmonary bypass in patients with a mean preoperative pulmonary pressure > 30 mmHg. Twenty patients scheduled for mitral valve replacement were studied in a prospective, randomized, double-blind trial. Patients receiving amrinone had a greater increase in cardiac index (CI) of 1.38 (+/-0.95) litre/min/m2 at separation vs 0.69 (+/-0.63) litre/min/m2 in the dobutamine group (P < 0.05). ⋯ Amrinone produced a larger decrease in pulmonary artery wedge pressure 8.0 (+/-4.4) mmHg vs 0.75 (+/-6.6) mmHg at separation; pulmonary artery systolic and diastolic pressures also were reduced more in the amrinone group. There were no differences in heart rate, mean arterial pressure, central venous pressure and right ventricular stroke work index between patient groups. In the doses chosen, the use of amrinone compared to dobutamine was associated with a reduction in pulmonary arterial pressures and an increase in cardiac index and right ventricular ejection fraction after separation from bypass in patients with severe preoperative pulmonary hypertension.
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Anaesth Intensive Care · Jun 1997
Randomized Controlled Trial Comparative Study Clinical TrialAdverse cardiovascular effects of ketamine infusion in patients with catecholamine-dependent heart failure.
The longterm effects of ketamine on haemodynamic parameters and exogenous catecholamine requirements were studied in twenty-five critically ill patients with catecholamine-dependent heart failure. Following sedation with midazolam (0.15 +/- 0.07, mg.kg-1.h-1) and sufentanil (0.88 +/- 0.33 microgram.kg-1.h-1), patients with impaired left ventricular function (left ventricular ejection fraction area 30 +/- 7%) were randomly assigned to receive ketamine (2.5 +/- 0.9 mg.kg-1.h-1) and midazolam (Group A) or remained on sufentanil/midazolam (Group B). Haemodynamic measurements were performed throughout the first 24 hours after randomization. ⋯ Neither group had significant changes of exogenous catecholamine requirement. In conclusion, ketamine exhibits potential negative cardiovascular effects in patients with catecholamine-dependent heart failure. Therefore, ketamine should not be considered a first line drug for longterm sedation of patients with impaired left ventricular function.