British journal of anaesthesia
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Clinical Trial
Serum concentrations of bupivacaine during prolonged continuous paravertebral infusion in young infants.
We have studied the efficacy of prolonged, continuous paravertebral infusion of bupivacaine for the management of post-thoracotomy pain in 22 infants with a median age of 1.5 weeks (range 1 day to 20.4 weeks). Immediately before chest closure, 0.25% bupivacaine 1.25 mg kg-1 was given into an extrapleural paravertebral catheter, inserted under direct vision. Subsequently, 0.125% bupivacaine with adrenaline 1:400000 was infused at a rate of 0.2 ml kg-1 h-1 for 48 h. ⋯ The technique provided effective post-operative pain relief in 86% of patients, with three patients requiring morphine in addition. Mean serum concentration of bupivacaine after 48 h was 1.60 (0.67) micrograms ml-1, but bupivacaine concentrations > 3 micrograms ml-1 were found in three patients at 30-48 h. There were no major complications relating to the technique, and paravertebral block was an effective method of providing prolonged post-thoracotomy analgesia in these young infants.
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Randomized Controlled Trial Comparative Study Clinical Trial
Interactions between mivacurium and pancuronium.
We have compared the dose-response relationships of mivacurium, pancuronium and their combination, and examined the interactions by isobolographic and fractional analyses. We studied 70 adult patients during nitrous oxide-fentanyl-propofol anaesthesia. The dose-response curves were determined by probit analysis. ⋯ When the first twitch (T1) of TOF recovered to 25%, each patient received mivacurium 46.2 micrograms kg-1. The times after administration of mivacurium until T1 25% in the mivacurium-pancuronium group were 6.4 (3.5-9.4) min and 49.8 (44.7-54.9) min, respectively (P < 0.0001). We conclude that the combination of mivacurium and pancuronium was synergistic and after pancuronium-induced neuromuscular block, mivacurium became a longer acting agent than the shorter agent.
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Randomized Controlled Trial Clinical Trial
Plasma dilution and the rate of infusion of Ringer's solution.
Changes in the volume of the fluid space expanded by i.v. infusion of Ringer's acetate solution have been analysed recently using mathematical models. Data obtained by such analyses allow simulation of the dilution of the plasma volume during infusion of the solution at different rates. To obtain basic kinetic data for such simulations, the plasma dilution-time curves were measured during and after i.v. infusion of Ringer's solution 25 ml kg-1 over 30 min in 15 healthy male volunteers (mean age 31 yr) and over 30, 45 and 80 min in six females (mean age 32 yr). Based on these experiments, nomograms were constructed from which the rate of infusion of Ringer's solution and the infusion time required to obtain a defined plasma dilution in both males and females can be estimated together with the infusion rate needed to maintain the dilution at the level reached.