British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Ultrasonography for ilioinguinal/iliohypogastric nerve blocks in children.
The ilioinguinal/iliohypogastric nerve block is a popular regional anaesthetic technique for children undergoing inguinal surgery. The success rate is only 70-80% and complications may occur. A prospective randomized double-blinded study was designed to compare the use of ultrasonography with the conventional ilioinguinal/iliohypogastric nerve block technique. ⋯ Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks can be achieved with significantly smaller volumes of local anaesthetics. The intra- and postoperative requirements for additional analgesia are significantly lower than with the conventional method.
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Randomized Controlled Trial Clinical Trial
Effect of clonidine pre-medication on propofol requirements during lower extremity vascular surgery: a randomized controlled trial.
Pre-medication with clonidine reduces the requirement for volatile agents during general anaesthesia. This may also be true for anaesthesia with propofol, but the amount of dose reduction has not been measured. Because clonidine also affects cardiac output and thus regional blood flow it could alter the pharmacokinetics of propofol. This randomized, double-blind placebo-controlled trial aimed to study the effect of clonidine pre-medication on dose requirement for propofol during lower extremity vascular surgery using the bispectral index (BIS) as a measure of anaesthetic depth. ⋯ Pre-medication with clonidine reduces the requirement for propofol, which is a pharmacokinetic effect and not a pharmacodynamic central sedative effect.
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Randomized Controlled Trial Comparative Study Clinical Trial
Randomized comparison of three methods of induction of anaesthesia with sevoflurane.
Rebreathing will occur if a low gas flow and a Mapleson D circuit are used to induce anaesthesia with a volatile anaesthetic agent. This has the advantage that it allows ventilation to be sustained when consciousness is lost, and specific manoeuvres such as breath-holding or vital capacity breaths are not needed to facilitate induction of anaesthesia. However, if the fresh gas flow were too small, this would slow induction by limiting the rate of delivery of the anaesthetic agent. To assess the impact of fresh gas flow and rebreathing, we compared induction using sevoflurane 8% given by three different methods. ⋯ In adult patients allowed to breathe normally, prompt and consistent inhalation induction of anaesthesia with sevoflurane is obtained when fresh gas flow is limited to 6 litre min(-1) from a Mapleson D circuit, but smaller flows are impractical.
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Comparative Study
Pressure recording analytical method (PRAM) for measurement of cardiac output during various haemodynamic states.
Cardiac output (CO) can be measured using the pressure recording analytical method (PRAM), which is a new, less invasive technique allowing beat-by-beat stroke volume monitoring from the pressure signals recorded in femoral or radial arteries. ⋯ In a porcine model we have demonstrated accuracy of PRAM during various haemodynamic states. PRAM is a reliable tool to detect changes in cardiac output in pigs and has ability as a basic research tool.
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One-lung ventilation-related hypoxaemia (OLV-RH) can occur in patients with healthy lungs. In this case, PEEP frequently improves oxygenation. The aim of this study was to determine, in a healthy lung model of OLV, whether the increase in PEEP improved oxygenation and whether the mechanisms involved include both inspiratory lung recruitment and an end-expiratory lung volume increase. Since inhaled nitric oxide (iNO) may have a synergistic effect on oxygenation in the case of PEEP-induced recruitment, their association was also tested. ⋯ In a healthy porcine lung model of OLV-RH, moderate PEEP can improve oxygenation. This effect implies both expiratory and inspiratory pulmonary recruitment. Co-administration of 4 p.p.m. iNO was ineffective.