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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Carbon dioxide clearance during high frequency jet ventilation. Effect of deadspace in a lung model.
The effects of the volume and length of deadspace on the clearance of carbon dioxide from a lung model have been investigated during high frequency jet ventilation (HFJV) at 1, 3 and 5 Hz. At 1 Hz, increasing the volume of the deadspace without changing the length caused a reduction in the clearance of carbon dioxide. ⋯ Furthermore, the clearance of carbon dioxide at 5 Hz was very inefficient compared with that at 1 Hz. It is concluded that, during HFJV, carbon dioxide is cleared most efficiently when the frequency is low enough for the delivered tidal volume to be greater than the volume of the morphological deadspace.
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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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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)