Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Plasma concentrations of glucose, lactate, epinephrine, norepinephrine, insulin, cortisol and growth hormone were measured in 28 healthy children, three to six years of age, before, during, and after lower abdominal surgery. The children received premedication with secobarbital, 6 mg.kg-1, pentazocine, 0.5 mg.kg-1, and atropine, 0.01 mg.kg-1 im. Fourteen children received general anaesthesia with nitrous oxide and halothane, and 14 others received caudal analgesia with 1.5% mepivacaine. ⋯ Plasma insulin and cortisol concentrations increased after surgery (P less than 0.05), and growth hormone concentration increased during and after surgery in the general anaesthesia group (P less than 0.05), but the concentrations of these hormones remained unchanged during and after surgery in the caudal analgesia group. Plasma lactate concentrations were unchanged in both groups. These results indicate that caudal analgesia suppresses the metabolic and endocrine responses to stress associated with lower abdominal surgery in children.
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Increasing numbers and varieties of electronic monitors are used in hospital operating rooms. Many of these are equipped with auditory alarms which are loud, insistent, or irritating, and thus are frequently disabled by the anaesthetist. This study was planned to evaluate two components of auditory alarm design which may influence the usefulness of the alarm: the perceived urgency of the auditory signal and its correlation with the urgency of the corresponding clinical situation. ⋯ The subjects were also tested for their ability to identify the alarm sounds correctly. The overall correct identification rate was 33%, and only two monitors were correctly identified by more than 50% of the subjects. The results of this study have implications for design and use of auditory alarms in hospitals and suggest the need for further research.
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Randomized Controlled Trial Comparative Study Clinical Trial
Large tidal volume ventilation improves pulmonary gas exchange during lower abdominal surgery in Trendelenburg's position.
Impaired pulmonary gas exchange is a common complication of general anaesthesia. Periodic hyperinflation of the lungs and large tidal volume ventilation were the first preventive measures to be widely embraced, but their effectiveness in clinical practice has never been clearly established by controlled clinical studies. To assess their effects in high-risk patients we studied 24 adults having lower abdominal gynaecological surgery in the Trendelenburg (head down) position. ⋯ There was significant deterioration of (A-a)DO2 at 30 min in Group A, whose lungs were first ventilated with CVT (81.6 +/- 7.2 to 166.8 +/- 13.7 mmHg, P less than 0.001); but not in Group B, whose lungs were first ventilated with HVT (77.0 +/- 9.9 to 104.4 +/- 16.8 mmHg). When Group A and B data were pooled there was no difference between randomized CVT and HVT, but improvement occurred after HI. In this model of compromised O2 exchange large inflation volumes (HVT and HI) were of considerable clinical benefit, HVT prevented and HI reversed the gas exchange disorder.
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Randomized Controlled Trial Clinical Trial
Transcranial Doppler sonography: nitrous oxide and cerebral blood flow velocity in children.
To determine the effect of nitrous oxide (N2O) on cerebral blood flow velocity (CBFV) and cerebrovascular resistance index (RI+) in children, ten ASA physical status I or II patients aged one to eight years old, scheduled for urological procedures, were studied. Anaesthesia was induced with thiopentone 2 mg.kg-1, fentanyl 5 micrograms.kg-1 and diazepam 0.3 mg.kg-1. Muscular relaxation was ensured by using vecuronium 0.1 mg.kg-1. ⋯ Ventilation was adjusted to achieve normocapnia. The CBFV increased when 70% N2/O2 was replaced by 70% N2O/O2 (P less than 0.05) while the CBFV decreased when 70% N2/O2 was readministered (P less than 0.05). Likewise, the CBFV decreased when 70% N2O/O2 was replaced by 70% N2/O2 (P less than 0.05) while the CBFV increased when 70% N2O/O2 was readministered (P less than 0.05).