British journal of anaesthesia
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The performance of cricoid pressure was studied in three groups of medical personnel likely to be involved in its application using the cricoid yoke and a test rig. The instrument enabled individuals who had no previous experience in the application of cricoid pressure to achieve results as good as those obtained by experienced anaesthetic staff. Furthermore, the instrument improved the consistency of the applied force in all groups, particularly if cricoid pressure was required for sustained periods of 30 s or more.
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Randomized Controlled Trial Comparative Study Clinical Trial
Continuous infusion of fentanyl or alfentanil for coronary artery surgery. Effects on plasma cortisol concentration, beta-endorphin immunoreactivity and arginine vasopressin.
Plasma cortisol, beta-endorphin immunoreactivity (PBEir) and arginine vasopressin (AVP) responses during and after the continuous infusion of fentanyl or alfentanil were studied in 19 patients undergoing coronary artery bypass grafting (CABG). Plasma cortisol concentration decreased significantly in both groups during the anaesthesia and surgery before cardiopulmonary bypass (CPB); an increase was evident during CPB in both groups, but a statistically significant increase was not observed during the rest of the study, including the awakening from anaesthesia. PBEir increased with both opiates immediately after initiation of CPB and remained so during the rest of the study. ⋯ It is concluded that, with continuous fentanyl and alfentanil infusions in a total dose relationship of 1:13 in patients undergoing CABG, cortisol and AVP responses to surgery and CPB can be suppressed. However, during recovery from anaesthesia, the attenuating effect of alfentanil seems to wear off more rapidly than that of fentanyl. PBEir response to CPB and emergence from anaesthesia could not be prevented with either analgesic.
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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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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.
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Randomized Controlled Trial Comparative Study Clinical Trial
Antagonism of profound neuromuscular blockade induced by vecuronium or atracurium. Comparison of neostigmine with edrophonium.
The effectiveness of neostigmine 0.07 mg kg-1 and edrophonium 0.8 mg kg-1 as antagonists of profound neuromuscular blockade induced by vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1 was studied in 59 healthy patients. The antagonists were administered 5 min after total ablation of the twitch response and the end-point of recovery was a train-of-four ratio of 70%. In 30 patients given vecuronium the mean time to reach this point (duration TOF70) was 66.7 min in the control group (no antagonist), 43.5 min in the group given neostigmine and 59.8 min in the group given edrophonium. ⋯ The durations TOF70 in the neostigmine (P less than 0.01) and edrophonium (P less than 0.01), groups were shorter than control. The duration TOF70 of the neostigmine group was shorter than in the edrophonium group (P less than 0.01). These results show that profound neuromuscular blockade cannot be rapidly antagonized by either of these two agents, but if reversal is required under these circumstances, neostigmine would be the more effective drug.