Canadian journal of anaesthesia = Journal canadien d'anesthésie
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This study examined the effect of flumazenil, a benzodiazepine antagonist, on aqueous humour pressure in dogs receiving either midazolam or no benzodiazepine. Twenty-four halothane-anaesthetized dogs were assigned to one of four groups. Group I (n = 6) received saline iv at 0, 45 and 90 min. ⋯ In Groups 3 and 4, midazolam decreased aqueous humour pressure from 18 +/- 2 mmHg (mean +/- SD) to 14 +/- 3 mmHg (P less than 0.001) and from 34 +/- 5 mmHg to 31 +/- 3 mmHg (P less than 0.01) respectively. Flumazenil given during continuous infusion of midazolam produced increases of aqueous humour pressure of 2 +/- 1 (P less than 0.01) to 5 +/- 2 mmHg (P less than 0.01) that lasted less than or equal to 12 min. It is concluded that at both normal and elevated aqueous humour pressures flumazenil produces statistically significant but clinically unimportant increases of aqueous humour pressure in anaesthetized dogs receiving midazolam, but not in dogs given no benzodiazepine.
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The relationships between the block-of-twitch and train-of-four fade in the presence of nondepolarizing neuromuscular blocking drugs (d-tubocurarine, vecuronium and pancuronium) were examined in vitro by measuring the contractile tension from mouse phrenic nerve-diaphragm preparations. The slope of the block/fade relationship differed between onset of and recovery from neuromuscular block following single doses of d-tubocurarine, vecuronium or pancuronium. ⋯ It is concluded that the block/fade relationship in the mouse phrenic nerve-diaphragm preparation is variable, and is related to the time course of the neuromuscular block. In addition, the block/fade relationships for d-tubocurarine, vecuronium and pancuronium did not differ when determined at steady-state.
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The effect of position, horizontal versus 5 degrees reverse Trendelenburg's, on the incidence of venous emboli during Caesarean section was evaluated in 207 patients. Venous emboli were diagnosed using precordial ultrasonic Doppler monitoring. In the horizontal position, 44% (60 of 134) parturients had venous emboli compared with 1% (1 of 73) parturients in the 5 degrees reverse Trendelenburg's position (P less than 0.0001). ⋯ In the epidural group, pulse oximetric haemoglobin oxygen desaturation and complaints of chest pain and/or dyspnoea were associated with the venous emboli. Venous emboli, probably air, occur frequently during Caesarean section with the patient in the horizontal position. This occurrence was minimized by placing the patient in the 5 degrees reverse Trendelenburg's position.
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Neostigmine 0.06 mg.kg-1 or edrophonium 1 mg.kg-1 were administered to two groups of 15 patients each for antagonism of pipecuronium-induced neuromuscular block at 20% spontaneous recovery of the first twitch (T1) of the train-of-four (TOF) stimulation. The mean onset of action (+/-SEM) of edrophonium (18.1 +/- 2.4 sec) was significantly more rapid (P less than 0.01) than that of neostigmine (47.6 +/- 4 sec), as were the times taken to attain a TOF ratio of 0.25 and 0.5. Nevertheless, the reversal time (time taken from the end of injection of the antagonist until TOF ratio value had reached 0.75) was significantly shorter (P less than 0.01) in the neostigmine than in the edrophonium group (499.3 +/- 62 vs 767 +/- 52 sec respectively). ⋯ Administration of one additional dose (one-third of the initial dose) of the same antagonist resulted in adequate antagonism in the remaining five patients in the neostigmine group and in nine patients in the edrophonium group. Two such doses were required in the remaining three patients in the latter group. The mean total dose of neostigmine and edrophonium employed in this study was 0.067 +/- 0.002 and 1.3 +/- 0.05 mg.kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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Paediatric microstomia may occur congenitally in the whistling face syndrome but is more often acquired after accidental thermal injuries such as biting an electrical extension cord or ingesting household lye. The surgical correction of microstomia includes separation and cosmetic reconstruction of the fused lips and postoperative oral splinting. ⋯ We report a case of paediatric microstomia after lye ingestion in which conventional direct laryngoscopy, flexible fibreoptic laryngoscopy, and multiple blind nasal approaches to tracheal intubation were unsuccessful. However, tracheostomy was avoided and successful tracheal intubation was accomplished using a new rigid tubular pharyngolaryngoscope.