Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Optimal stimulating current for train-of-four stimulation in conscious subjects.
The purpose of this study was to determine the optimal stimulating current for train-of-four (TOF) monitoring with regard to the return of TOF response and the discomfort associated with TOF. Two variables were examined at 60, 50, 40, 30, and 20 mA: (1) times from administration of vecuronium 80 micrograms.kg-1 to returns of responses to TOF determined accelographically in 75 anaesthetised patients and (2) discomfort associated with TOF in 15 awake volunteers using visual analogue scale (VAS). Times to return of the first response to stimulation at 60, 50, 40, and 30 mA were not different (29.1 +/- 11.2, 30.1 +/- 12.0, 31.9 +/- 12.6, and 35.4 +/- 14.2 min, respectively, mean +/- SD). ⋯ The VAS associated with TOF at 60, 50, 40, 30, and 20 mA were 7.3 +/- 1.9, 6.7 +/- 1.8, 6.0 +/- 2.0, 4.1 +/- 2.1, and 2.7 +/- 2.3, respectively. The VAS at 30 mA was less than at 60 and 50 mA (P < 0.05), and at 20 mA was less than at 60, 50, and 40 mA (P < 0.05). In conclusion it is suggested that, when testing conscious patients, 30 mA is the optimal stimulating current for TOF monitoring because it represents the best compromise of neuromuscular monitoring and patient discomfort.
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Comparative Study
Persistent low cerebral blood flow velocity following profound hypothermic circulatory arrest in infants.
Acute neurological morbidity following repair of congenital heart disease (CHD) in infancy is well recognized, particularly with the modalities of hypothermic cardiopulmonary bypass (CPB) and profound hypothermic circulatory arrest (PHCA). Reduced O2 delivery (perfusion defect) during rewarming following PHCA has been shown in the operating room. This reduction in cerebral blood flow coincides with disordered cerebral metabolism and oxygen utilisation after PHCA. ⋯ This study demonstrates a sustained reduction in the CBFV pattern following PHCA into the postoperative period despite adequate cerebral perfusion pressures. This abnormality correlates with electroencephalographic aberrations documented after PHCA. It supports the concept of a prolonged unreactive cerebrovascular bed which could potentially contribute to the acute neurological morbidity following PHCA in neonates.
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The safe, expeditious conduct of ambulatory surgical care can succeed only by careful selection of patients and procedures, appropriate intra- and postoperative anaesthetic management, and safe, timely discharge of patients. Discharge of patients should be achieved without compromising the quality of patient care. As the patients presenting for ambulatory surgery become more complex and compromised, and their surgical treatment more demanding, it is important to replace, or at least supplement, our existing qualitative, subjective method for evaluating patient discharge with a quantitative, objective technique to provide a simple and consistent method of determining home readiness. ⋯ Reduction in the length of stay in an ambulatory surgery unit by the prompt and safe discharge of patients can help to reduce costs and improve unit efficiency. For certain surgical procedures, ambulatory treatment is cheaper, even allowing for treatment failures and readmissions. However, we must remember that the application of any discharge criteria scoring system must include common sense, clinical judgment, and home-readiness of an outpatient does not assume street fitness.
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This study was undertaken to evaluate the effect of isoflurane anaesthesia on the hypothalamic contents of both prostaglandin D2 and E2 which affect the sleep-wakefulness cycle. Sixty-three Wistar rats were divided into three equal groups, control, isoflurane and recovery groups. Twenty-one rats of the control did not receive isoflurane. ⋯ The hypothalamic PGE2 contents were 381.4 +/- 139.0 pg.g-1 for the control group, 183.3 +/- 26.4 pg.g-1 for the isoflurane group and 312.2 +/- 96.0 pg.g-1 for the recovery group, respectively. The hypothalamic PGD2 and PGE2 contents in the isoflurane group were lower (P < 0.05) than those in the control and recovery groups, while both the PGD2 and PGE2 contents of the control and the recovery groups were similar. We conclude that decreased hypothalamic PGD2 and PGE2 contents may be related to some manifestations of general anaesthesia with isoflurane.