British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Continuous infusion of fentanyl or alfentanil for coronary artery surgery. Plasma opiate concentrations, haemodynamics and postoperative course.
Nine patients received a mean total dose of 110 micrograms kg-1 of fentanyl and 10 patients received alfentanil 1379 micrograms kg-1 as a continuous infusion during coronary artery bypass grafting (CABG). Circulatory stability was well maintained through the induction of anaesthesia and a similar cardiovascular course was achieved with both agents, with the exception of small differences in heart rate and cardiac index immediately before tracheal intubation. ⋯ With the continuous infusion techniques, plasma opiate concentrations could be maintained well above the awakening values during cardiopulmonary bypass. In a total dose ratio of 1:13, fentanyl and alfentanil produced similar haemodynamic profiles and clinical courses in patients undergoing CABG.
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Comparative Study
Antagonism of atracurium-induced neuromuscular blockade by neostigmine or edrophonium.
Antagonism of atracurium-induced neuromuscular blockade by neostigmine or edrophonium has been studied using the tetanic (50 Hz) and train-of-four (2 Hz) or single twitch responses of the adductor pollicis muscle in 22 anaesthetized patients. A further nine patients not given an anticholinesterase acted as a control group. ⋯ When edrophonium is given at the commencement of recovery, the initial rapid antagonism of tetanic block is not sustained, whereas antagonism by neostigmine is more persistent and the recovery phase is significantly shortened. In a further two groups of patients (n = 5) given atracurium 0.3 mg kg-1 i.v., antagonism was not attempted until the peak height of the tetanic contraction had reached approximately 50% of the control value.(ABSTRACT TRUNCATED AT 250 WORDS)
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The effects of atracurium and alcuronium on the evoked mechanical and electromyographic responses of the adductor pollicis were investigated in 30 adult patients. The ulnar nerve was stimulated with trains of four supramaximal pulses of 0.2 ms duration and a frequency of 2 Hz at intervals of 20 s. The mechanical response was measured using a strain gauge force transducer and the evoked compound action potential (ECAP) was recorded simultaneously using a Medelec MS91 electromyography system. ⋯ There was no significant quantitative difference between the rates of antagonism of alcuronium and atracurium when assessed by the mechanical first response ratio. Electromyographic first response and electromyographic and mechanical train-of-four ratios recovered more rapidly in the atracurium group. These findings suggest that the differences between mechanical and electromyographic measurements of neuromuscular blockade are drug-specific and are more pronounced during the onset of blockade than during its antagonism by neostigmine.