Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Intrathecal fentanyl prolongs sensory bupivacaine spinal block.
The purpose of investigation was to study the effect of intrathecal fentanyl on the onset and duration of hyperbaric bupivacaine-induced spinal block in adult male patients. Forty-three patients undergoing lower extremity or genitourinary surgery were enrolled to receive either 13.5 mg hyperbaric bupivacaine 0.75% + 0.5 ml CSF it, (Group I) or 13.5 mg hyperbaric bupivacaine 0.75% + 25 micrograms fentanyl it, (Group II) according to a randomized assessor-blind protocol. The onset and duration of sensory block were assessed by pinching the skin with forceps in the midclavicular line bilaterally every two minutes for first twenty minutes and then every five to ten minutes. ⋯ Fewer patients demanded pain relief in the fentanyl-treated group than in the control group in the early postoperative period (19% vs 59%; P < 0.05). Episodes of hypotension were more frequent in the fentanyl-treated group than in the control group (43% vs 14%; P < 0.05). We conclude that fentanyl, 25 micrograms it, prolonged the duration of bupivacaine-induced sensory block (sensory regression to L1 dermatone) by 28% and reduced the analgesic requirement in the early postoperative period following bupivacaine spinal block.
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Randomized Controlled Trial Comparative Study Clinical Trial
Edrophonium requirements for reversal of deep neuromuscular block following infusion of mivacurium.
Mivacurium is a new non-depolarizing muscle relaxant consisting of three stereoisomers. The two active isomers (cis-trans and trans-trans) undergo rapid metabolism by plasma cholinesterase (t1/2 beta < 2 min). Due to its rapid elimination, the need for reversal of mivacurium-induced neuromuscular block is controversial, and to date there have been no studies evaluating reversal of deep blocks. ⋯ Two patients (PLAC group), had dibucaine numbers and cholinesterase levels consistent with an EUEA genotype, whereas the two patients with delayed recovery in the EDR-1 group had characteristics of a normal genotype. We conclude that a very low dose of edrophonium (0.125 mg.kg-1) hastens reversal of deep mivacurium-induced neuromuscular block by approximately four minutes, and that edrophonium doses exceeding 0.125 mg.kg-1 provide no additional benefit. Heterozygous patients with atypical plasma cholinesterase levels, as well as certain individuals with normal dibucaine numbers and plasma cholinesterase activity, are at risk for prolonged neuromuscular block, but the block is easily reversed with edrophonium.
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Randomized Controlled Trial Comparative Study Clinical Trial
Oral clonidine premedication reduces vomiting in children after strabismus surgery.
This is a prospective randomized double-blind trial conducted to determine whether preoperative orally administered clonidine causes or potentiates postoperative vomiting in 140 children (3-12 yr) undergoing strabismus surgery. They were all inpatients and classified randomly into four groups (n = 35 each); placebo (control), diazepam 0.4 mg.kg-1, clonidine 2 micrograms.kg-1, and clonidine 4 micrograms.kg-1. These agents were administered 93-112 min (mean; 100 min) before the anticipated time of induction of anaesthesia. ⋯ However, low-dose clonidine was ineffective. These data suggest that preanaesthetic medication with clonidine 4 micrograms.kg-1 may be useful for preventing emesis following strabismus surgery. This property of clonidine indicates that it may be superior to other sedative premedicants such as diazepam and midazolam.
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Randomized Controlled Trial Comparative Study Clinical Trial
The triple airway manoeuvre for insertion of the laryngeal mask airway in paralyzed patients.
The efficacy of the triple airway manoeuvre (mouth opening, head extension and jaw thrust) for insertion of the laryngeal mask airway (LMA) was compared with the standard insertion method. One hundred paralyzed patients were allocated randomly into two groups: in the control group (n = 50) the LMA was inserted by the standard method, and in the other (TAM group, n = 50) by the triple airway manoeuvre. In ten patients of each group, the position of the LMA and the epiglottis was assessed radiographically before insertion, after insertion but before cuff inflation, and after cuff inflation. ⋯ After cuff inflation the glottis was completely visible fibreoptically in 66% in the TAM group, compared with 14% in the control group (P < 0.001). Complete downfolding of the epiglottis was seen in 10% in the control group and none in the TAM group (P < 0.05). We conclude that in paralyzed patients LMA insertion with the triple airway manoeuvre provides wider pharyngeal space and decreases the incidence of epiglottic downfolding by the LMA compared with the standard method.
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Randomized Controlled Trial Clinical Trial
Optimal stimulating current for train-of-four stimulation in conscious subjects.
The purpose of this study was to determine the optimal stimulating current for train-of-four (TOF) monitoring with regard to the return of TOF response and the discomfort associated with TOF. Two variables were examined at 60, 50, 40, 30, and 20 mA: (1) times from administration of vecuronium 80 micrograms.kg-1 to returns of responses to TOF determined accelographically in 75 anaesthetised patients and (2) discomfort associated with TOF in 15 awake volunteers using visual analogue scale (VAS). Times to return of the first response to stimulation at 60, 50, 40, and 30 mA were not different (29.1 +/- 11.2, 30.1 +/- 12.0, 31.9 +/- 12.6, and 35.4 +/- 14.2 min, respectively, mean +/- SD). ⋯ The VAS associated with TOF at 60, 50, 40, 30, and 20 mA were 7.3 +/- 1.9, 6.7 +/- 1.8, 6.0 +/- 2.0, 4.1 +/- 2.1, and 2.7 +/- 2.3, respectively. The VAS at 30 mA was less than at 60 and 50 mA (P < 0.05), and at 20 mA was less than at 60, 50, and 40 mA (P < 0.05). In conclusion it is suggested that, when testing conscious patients, 30 mA is the optimal stimulating current for TOF monitoring because it represents the best compromise of neuromuscular monitoring and patient discomfort.