British journal of anaesthesia
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Comparative Study
Comparison of neostigmine-induced recovery with spontaneous recovery from mivacurium-induced neuromuscular block.
In 24 ASA I-II adults anaesthetized with thiopentone, fentanyl and nitrous oxide in oxygen, we studied neuromuscular transmission with isometric adductor pollicis monitoring. Patients received mivacurium 0.2 mg kg-1 followed by an infusion lasting at least 60 min and adjusted to maintain twitch height at 1-5%. After termination of the mivacurium infusion, when twitch height spontaneously regained 25% of its control value, the patients were allocated to two groups of 12 patients each. ⋯ All patients in group NEO recovered to a TOF ratio greater than 0.7 after 6 min compared with 15 min in group SPO (P < 0.005). A TOF ratio greater than 0.9 was observed in all patients in group NEO compared with only six in group SPO (P < 0.025). Nevertheless, RF50HZ and RF100HZ did not differ significantly (0.92 (0.01) (group NEO), 0.91 (0.01) (group SPO) and 0.83 (0.02) (group NEO), 0.78 (0.03) (group SPO), respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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We have compared arterial pressures measured by an indwelling radial cannula with those obtained non-invasively by the Finapres 2000 (Ohmeda) during spinal anaesthesia for lower segment Caesarean section. The digital outputs of both pressures were recorded using a computerized system. We studied 20 patients, yielding a total of 18,772 data points after elimination of data recorded during arterial flushing and erroneous results from each source. ⋯ Some patients and some periods of readings reflected a high degree of precision and little bias. However, unexplained large differences in pressure and trends of change that were out of phase over time occurred frequently. We conclude that the Finapres cannot be recommended as a monitor of arterial pressure in this group of patients in whom sudden hypotension may be a threat to maternal or fetal outcome.
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We describe a miniature electrochemically driven, wrist-worn infusion pump. Generation of gas by an electrolytic reaction compresses a reservoir containing medication and provides a predictable and controllable infusion rate. ⋯ This portable system, using a novel motive force, has advantages of convenience over larger systems and has sophisticated features not present in existing small systems. It has potential as a routine PCA device and it may have uses in other situations requiring convenient infusion or intermittent injection in an ambulatory setting.
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Randomized Controlled Trial Clinical Trial
Uteroplacental and fetal haemodynamics and cardiac function of the fetus and newborn after crystalloid and colloid preloading for extradural caesarean section anaesthesia.
We have studied the effects of randomized preloading with either a crystalloid (lactated Ringer's) 15 ml kg-1 or colloid (hydroxyethyl starch) 7.5 ml kg-1 solution in 20 parturients undergoing elective Caesarean section under extradural anaesthesia, on blood flow in maternal placental and non-placental uterine and placental arcuate arteries and in fetal umbilical, renal and middle cerebral arteries, using a pulsed colour Doppler technique. Simultaneously, fetal and neonatal myocardial function were investigated by pulsed Doppler and M-mode echocardiography. ⋯ There were no differences in fetal or neonatal myocardial function between the groups, and the outcome of the newborn infants were uneventful in all cases. These results suggest that preloading with either a crystalloid or colloid solution may lead to different uterine and fetal haemodynamics but these solutions had only minimal effects on fetal and neonatal myocardial performance and no effect on the clinical condition of newborns in uncomplicated pregnancies.
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Randomized Controlled Trial Clinical Trial
Convective warming after hypothermic cardiopulmonary bypass.
In a randomized, controlled study, we found that convective warming after hypothermic cardiopulmonary bypass did not accelerate the rate of warming of the body core or the time to tracheal extubation. The relationship between body core and shell temperature, however, was affected. ⋯ Convective warming was delivered using BairHugger (Augustine Medical Inc., MN, USA) and Warm Touch (Mallinckrodt Medical UK Ltd, Northampton, UK) blankets. There was no difference between the performance of each blanket when powered by the BairHugger 500 power unit set at its medium setting of 38 degrees C, and when chest drain and radial artery cannulation sites were left exposed for observation.