British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Randomized controlled study of colloid preload before spinal anaesthesia for caesarean section.
We randomized women having elective Caesarean section to receive either no preload (control group, n=33) or 4% gelatin solution (Gelofusine) 15 ml kg(-1) (colloid group, n=35) i.v. before spinal anaesthesia. Intravenous metaraminol was titrated at 0.25-0.75 mg min(-1) to maintain systolic arterial pressure (SAP) in the target range 90-100% of baseline after the spinal injection. ⋯ Nausea was less frequent in the colloid group (6 vs 24%) but neonatal outcome was similar in the two groups. Colloid preload improved haemodynamic stability but did not affect neonatal outcome when arterial pressure was maintained with an infusion of metaraminol during spinal anaesthesia for Caesarean section.
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Review Case Reports
Grand mal convulsion and plasma concentrations after intravascular injection of ropivacaine for axillary brachial plexus blockade.
We report a patient to whom ropivacaine 1.1 mg kg(-1) was administered for brachial plexus blockade and who developed grand mal convulsions because of inadvertent i.v. injection. No symptoms of cardiovascular toxicity occurred. ⋯ The measured total plasma concentrations of ropivacaine were 3.3, 1.6, 1.2 and 1.0 mg litre(-1) respectively. Initial plasma concentration after the end of the injection period was estimated at 5.75 mg litre(-1) using a two-compartment pharmacokinetic model.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison between dexmedetomidine and propofol for sedation in the intensive care unit: patient and clinician perceptions.
The alpha2 agonist dexmedetomidine is a new sedative and analgesic agent which is licensed in the USA for post-operative intensive care sedation. We compared dexmedetomidine with propofol in patients requiring sedation in intensive care. Twenty adult patients expected to require a minimum of 8 h artificial ventilation after surgery were randomized to receive sedation with either dexmedetomidine or propofol infusions. ⋯ From the clinician's and patient's perspectives, dexmedetomidine is a safe and acceptable sedative agent for those requiring intensive care. The rate pressure product is reduced in patients receiving dexmedetomidine, which may protect against myocardial ischaemia. Dexmedetomidine reduces the requirement for opioid analgesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of minor surgery and endotracheal intubation on postoperative breathing patterns in patients anaesthetized with isoflurane or sevoflurane.
We studied the effects of minor surgery and endotracheal intubation on postoperative breathing patterns. We measured breathing patterns and laryngeal resistance during the periods immediately before intubation (preoperative) and immediately after extubation following minor surgery (postoperative) in eight patients anaesthetized with sevoflurane and eight patients anaesthetized with isoflurane, breathing spontaneously through a laryngeal mask airway at a constant end-tidal anaesthetic concentration (1.0 MAC). In both sevoflurane-anaesthetized and isoflurane-anaesthetized patients, expiratory time was reduced and inspiratory and expiratory laryngeal resistance increased after surgery. ⋯ Occlusion pressure did not change and T(I) was greater in isoflurane-anaesthetized patients after surgery. Minor surgery may have a small but significant influence on breathing and increased laryngeal resistance following endotracheal intubation may modulate these changes. The difference in breathing pattern between sevoflurane and isoflurane may be a result of different responses of the central nervous system to different anaesthetics in the presence of increased laryngeal resistance.
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Randomized Controlled Trial Comparative Study Clinical Trial
Influence of equianaesthetic concentrations of nitrous oxide and isoflurane on regional cerebral blood flow, regional cerebral blood volume, and regional mean transit time in human volunteers.
Nitrous oxide and isoflurane have cerebral vasodilatory effects. The use of isoflurane in neuroanaesthesia is widely accepted, whereas the use of nitrous oxide in neuroanaesthesia is still the subject of debate. In the present study, contrast-enhanced magnetic resonance (MR) perfusion measurement was used to compare the effects of 0.4 MAC nitrous oxide (n=9) and 0.4 MAC isoflurane (n=9) on regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and regional mean transit time (rMTT) in spontaneously breathing human volunteers. ⋯ Isoflurane, by contrast, increased rCBF and rCBV in basal ganglia more than did nitrous oxide. An increased rMTT was caused by a relatively greater increase in rCBV than in rCBF supratentorially by isoflurane and infratentorially by nitrous oxide. In conclusion, nitrous oxide increases rCBF and rCBV predominantly in supratentorial grey matter, whereas isoflurane increases rCBF and rCBV predominantly in infratentorial grey matter.