Anaesthesia and intensive care
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Anaesth Intensive Care · Oct 1998
Randomized Controlled Trial Multicenter Study Clinical TrialA comparison of 0.5% ropivacaine and 0.5% bupivacaine for axillary brachial plexus anaesthesia.
The purpose of this study was to compare the use of 0.5% ropivacaine with 0.5% bupivacaine for axillary brachial plexus anaesthesia. Sixty-six patients undergoing upper limb surgery were enrolled in a double-blind, randomized, multicentre trial. Five patients were subsequently excluded for various reasons. ⋯ These parameters were not statistically different. The duration of partial motor block at the wrist (6.8 v 16.4h) and hand (6.7 v 12.3h) was significantly longer with bupivacaine. Ropivacaine 0.5% and bupivacaine 0.5% appeared equally efficacious as long-acting local anaesthetics for axillary brachial plexus block.
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Anaesth Intensive Care · Oct 1998
Randomized Controlled Trial Clinical TrialA comparison of three fluid-vasopressor regimens used to prevent hypotension during subarachnoid anaesthesia in the elderly.
We aimed to compare the efficacy of fluid preloading with two recently recommended fluid-vasopressor regimens for maintaining blood pressure during subarachnoid anaesthesia in the elderly. Sixty elderly patients requiring surgery for traumatic hip fractures received subarachnoid anaesthesia using 0.05 ml/kg of 0.5% heavy bupivacaine. Hypotension, i.e. systolic arterial pressure < 75% of baseline, was prevented or treated by: A--normal saline 16 ml/kg plus intravenous ephedrine boluses (0.1 mg/kg); B--normal saline 8 ml/kg plus intramuscular depot ephedrine (0.5 mg/kg); or C--Haemaccel 8 ml/kg plus metaraminol infusion. ⋯ During the first hour, hypotension was present for 47%, 25% and 20% of the time in groups A, B and C respectively and overcorrection of systolic arterial pressure occurred in 19% of the time in group C. We conclude that treatment A was inadequate in preventing hypotension. Treatments B and C were more effective but were associated with an increased heart rate and overcorrection of systolic arterial pressure respectively.
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Anaesth Intensive Care · Oct 1998
Randomized Controlled Trial Clinical TrialClosed circuit anaesthesia in ventilated patients using the Komesaroff vaporizer within the circle.
A study was undertaken to assess the performance of the Komesaroff vaporizer, placed within the circuit, in ventilated patients during maintenance of closed circuit anaesthesia with halothane or isoflurane. Following intravenous induction, anaesthesia was maintained by inhalation. This was achieved using a conventional vaporizer outside the circle for the first 10 minutes to manage the fast uptake phase. ⋯ The Komesaroff vaporizer dial was positioned at between the first and second division and end-tidal volatile anaesthetic agent levels were measured. This study demonstrated that at dial positions 1 or 1.5 with either agent, the end-tidal volatile concentration plateaued at clinically acceptable levels. The Komesaroff vaporizer can therefore be used safely in ventilated patients to maintain closed circuit anaesthesia provided clinical observation and monitoring are meticulous.
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Anaesth Intensive Care · Oct 1998
Comparative StudyA comparison of the T-piece, Venturi T-piece and T-bag for emergence with the laryngeal mask.
We have compared the performance of a standard T-piece, a Venturi T-piece and a T-bag (T-piece with a small reservoir bag) for emergence with the laryngeal mask airway in 20 awake volunteers. FiO2, ETCO2 and FiCO2 were measured at oxygen flow rates of 2, 4 and 6 l.min-1 during three different breathing patterns: normal tidal volume, respiratory rate 12 .min-1; normal tidal volume, respiratory rate 20 .min-1; high tidal volume, respiratory rate 12 .min-1. The T-piece and T-bag delivered a higher overall average FiO2 than the Venturi T-piece (P < 0.00001). ⋯ The FiCO2 was never higher than 0.2% in any subject. We conclude that the T-piece and T-bag are more effective oxygen enrichment devices than the Venturi T-piece. The T-bag provides a useful visual signal about depth and frequency of respiration.
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Anaesth Intensive Care · Oct 1998
Case ReportsClearance of an obstructed endotracheal tube with an arterial embolectomy catheter with the patient in the prone position.
The obstruction of an endotracheal tube with the patient in the prone position creates major anaesthetic difficulties that may result in patient morbidity and mortality. We describe a case involving the clearing of a blocked endotracheal tube with an arterial embolectomy catheter and discuss the relevance to anaesthetic practice.