British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of recovery after neuromuscular blockade by atracurium or pancuronium.
Thirty patients were randomly allocated to receive either atracurium or pancuronium for neuromuscular blockade during surgery. At the end of the operation residual paralysis was antagonized with neostigmine. ⋯ Double vision was significantly more frequent at up to 1 h when pancuronium had been used. At no time was there any significant difference between the two groups in respect of the 5-s head lift or, after 30 min, in the measurement of inspiratory force.
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In summary, CPB provides a complex set of physiological circumstances during which the patient is subjected to severe physiological alterations with surprisingly few adverse sequelae. Our ultimate goal in performing medical research is to provide scientific insights that improve patient care. Results of studies of animal models may not always be applicable to man. Although CPB possesses faults inherent to any experimental model, it nonetheless provides a unique opportunity to study safely and effectively a variety of physiological and pharmacological variables that affect cardiovascular functions in man.
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Randomized Controlled Trial Comparative Study Clinical Trial
Double-blind, multiple-dose comparison of buprenorphine and morphine in postoperative pain of children.
In a randomized double-blind study of 57 children (aged 6 months-6 yr), pain following lateral thoracotomy was relieved with repeated i.v. doses of morphine 100 or 50 micrograms kg-1, or buprenorphine 3.0 or 1.5 micrograms kg-1. The same drug and dosage were continued and cardioventilatory indices, pain intensity and sedation measured for an observation period of 24 h. The sums of the pain intensity differences were equal in all groups. ⋯ The total consumption of both morphine and buprenorphine was less when the smaller bolus doses were used. Two patients developed a degree of ventilatory depression following repeated doses of buprenorphine. Buprenorphine was equal to morphine as a postoperative analgesic.
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The haemodynamic effects of propofol, given as a single dose of 2 mg kg-1 immediately followed by a continuous infusion of 6 mg kg-1 h-1, were studied in 10 elderly patients premedicated with lorazepam 1 mg i.v. All patients breathed room air spontaneously. ⋯ Cardiac output was not affected at any time nor were stroke volume and heart rate. We conclude that the arterial hypotension associated with the induction and infusion of propofol is mainly a result of a decrease in afterload without compensatory increases in heart rate or cardiac output.
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Electromagnetic flow probes were used to measure the fraction of the pulmonary blood flow perfusing the left lower lobe (Ql/Qt) in 16 anaesthetized, open-chest dogs in order to study the effects of right lung airway pressure on the distribution of blood flow to a hypoxic lung lobe. Ventilation of the lobe with 7% oxygen in nitrogen resulted in a 37% reduction in Ql/Qt at the beginning and end of the main procedure, thus confirming that the hypoxic pulmonary vasoconstrictor response was unchanged throughout the study. The effects of varying mean airway pressure to the right lung by changing inspiratory:expiratory time ratio and by the addition of a positive end-expiratory pressure were studied when the left lower lobe was insufflated with oxygen or 7% oxygen in nitrogen, or was collapsed. ⋯ However, changing mean airway pressure in the right lung produced no significant changes in Ql/Qt in any of the different lobar conditions or when collapse was produced after fluid loading. Fluid loading during collapse increased cardiac output and pulmonary vascular pressures and increased Ql/Qt to a value which was not significantly different from lobar ventilation with 7% oxygen in nitrogen. It is concluded that moderate increases in mean airway pressure do not increase Ql/Qt when this has been reduced by exposure of the lobe to mixed venous blood-gas tensions.