British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Onset of neuromuscular block after tourniquet inflation: comparison of suxamethonium with vecuronium.
To determine the influence of circulatory factors on onset of neuromuscular block, we have measured twitch height in an arm with a tourniquet inflated during onset and compared this with data from a control arm in 20 patients under fentanyl-thiopentone-nitrous oxide-isoflurane anaesthesia. Patients were allocated randomly to receive either vecuronium 0.1 mg kg-1 (n = 10) or suxamethonium 1 mg kg-1 (n = 10). The EMG response of the first dorsal interosseous to single twitch stimulation of the ulnar nerve every 10 s was recorded in both arms. ⋯ Maximum block was only 74 (20)% in the tourniquet arm compared with 97 (5)% in the perfused arm (P < 0.05). The difference in maximum neuromuscular block between arms was 4 (3)% in the vecuronium group and 22 (17)% in the suxamethonium group (P < 0.01). We conclude that during onset, neuromuscular block continued to increase in spite of interruption of blood flow, and this increase was greater with vecuronium than with suxamethonium.(ABSTRACT TRUNCATED AT 250 WORDS)
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Forty consecutive patients who could not be weaned from mechanical ventilation in the intensive care unit (ICU) entered a multidisciplinary progressive care programme (PCP). The mean number of hours per day of ventilatory support was 19.9 at the time of transfer but only 6.7 at discharge. ⋯ Seventy-six percent were alive 1 yr after discharge and 80% of patients were discharged directly from the PCP to their homes. Mental and emotional scores in a quality of life questionnaire (SF 36) were normal, but physical function remained limited.
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Randomized Controlled Trial Comparative Study Clinical Trial
EEG arousal during laryngoscopy and intubation: comparison of thiopentone or propofol supplemented with nitrous oxide.
We studied EEG arousal after laryngoscopy and intubation with standardized bolus induction of anaesthesia. Twenty patients were prospectively allocated randomly to induction with propofol 3 mg kg-1 (n = 10) or thiopentone (6 mg kg-1 (n = 10) and 50% nitrous oxide in oxygen. Neuromuscular block was produced with vecuronium 0.2 mg kg-1 given 30 s after induction. ⋯ This EEG arousal was greater in the thiopentone group, despite the fact that EEG depression was similar to that produced by propofol before laryngoscopy and intubation. Propofol and thiopentone in combination with nitrous oxide had similar cortical depressant effects, but propofol appeared to depress subcortical nociceptive processing more than thiopentone. While the degree of cortical EEG depression seems less useful for predicting reaction to subsequent nociception, EEG arousal reactions may prove suitable for monitoring intra-anaesthetic nociception and its modulation.
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To ascertain the effects of chronic renal failure on the pharmacokinetics of 1R-cis 1'R-cis atracurium besylate (a stereoisomer, designated 51W89), we gave a bolus dose of 0.1 mg kg-1 (2 x ED95) to 17 patients with end-stage renal failure and to 15 patients with normal renal function undergoing elective surgery. All patients received thiopentone, fentanyl and midazolam i.v. and 70% nitrous oxide in oxygen. Blood samples were obtained over 8 h and plasma analysed for 51W89 and laudanosine concentration, using high pressure liquid chromatography. ⋯ The typical value of T1/2 beta was 4.2 min longer in renal failure than in the healthy patients (34.2 vs 30.0 min, P < 0.005). In the healthy patients, clearance of 51W89 was greater in males, but it decreased with increasing age by approximately 1.5 ml min-1 yr-1. Mean plasma laudanosine concentrations were significantly higher in the renal failure group; nevertheless, they were approximately one-tenth of those reported after atracurium.