British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Post-tetanic burst: a new monitoring method for intense neuromuscular block.
A new stimulation pattern for evaluation of intense neuromuscular block (post-tetanic burst (PTB)) was compared with post-tetanic twitch (PTT) during spontaneous recovery from vecuronium-induced neuromuscular block. Thirty adult patients were allocated to two equal groups and we measured times from administration of vecuronium 0.1 mg kg-1 to return of PTB and PTT responses, and evoked responses to PTB and PTT stimuli. For PTB stimulation, a 50-Hz tetanus was applied at 50 mA for 5 s, and after a pause of 3 s, a 50-Hz burst stimulation was applied, consisting of three impulses at 50 mA. ⋯ Similarly, PTT consisted of a tetanus, a 3-s pause and one single twitch stimulation repeated every 5 min. Time to return of the PTB response was significantly shorter than that of PTT (mean 23.7 (SD 7.9) compared with 30.7 (7.0) min) (P = 0.0160), although evoked responses to PTB did not differ significantly from those of PTT throughout recovery from vecuronium-induced neuromuscular block. This study suggested that PTB was more sensitive in evaluating intense neuromuscular block than PTT.
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Comparative Study
Transient radicular irritation after spinal anaesthesia with hyperbaric 5% lignocaine.
We have studied prospectively 600 patients who had spinal anaesthesia for minor surgery, to evaluate the incidence of transient radicular irritation after the block. The anaesthetic agent (hyperbaric 5% lignocaine, hyperbaric 0.5% bupivacaine or plain 0.5% bupivacaine) was chosen according to the anticipated duration of surgery. We obtained information after operation from 537 patients (282 by telephone, 255 by letter). ⋯ Two patients complained of symptoms after hyperbaric 0.5% bupivacaine but these were atypical compared with pain after lignocaine. None of the patients anaesthetized with plain bupivacaine had similar complaints. We conclude that the use of 5% hyperbaric lignocaine for spinal anaesthesia should be reconsidered.
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To determine the effects of cardiopulmonary bypass (CPB) on tracheal cuff pressure, we have measured intracuff pressure (ICP) in 29 consecutive patients undergoing cardiac surgery with CPB. Premedication comprised hyoscine and, after induction of anaesthesia with diazepam and fentanyl, followed by vecuronium, the trachea was intubated using a Portex Profile tracheal tube. Anaesthesia was maintained with high-dose fentanyl and 100% oxygen. ⋯ ICP changed significantly during CPB, decreasing to 8.0 (1.0) mm Hg before rewarming (P < 0.01 vs immediately before CPB) and increasing to 17.0 (0.6) mm Hg after the start of rewarming (P < 0.01 vs before rewarming). After CPB, ICP did not differ significantly from that immediately before CPB. We conclude that the decrease in ICP during the hypothermic phase of CPB may protect the tracheal mucosa against hypotensive ischaemic injury.