Anaesthesia and intensive care
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Anaesth Intensive Care · Aug 1996
Comparative StudyBrain and blood concentrations of propofol after rapid intravenous injection in sheep, and their relationships to cerebral effects.
The time-course of propofol concentrations in the blood and brain following rapid administration of three doses were examined using a sheep preparation and regional pharmacokinetic techniques. These were compared to the time-course of cerebral effects of propofol reported previously. ⋯ There was evidence that the effect of propofol on cerebral blood flow altered its own rate of elution from the brain. Hysteresis between arterial propofol concentrations and cerebral effects following rapid i.v. administration therefore appears to have a pharmacokinetic basis, and conventional compartmental pharmacokinetic analysis using blood concentrations alone may fail to accurately predict the time-course of both brain propofol concentrations and depth of anaesthesia.
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Anaesth Intensive Care · Aug 1996
Comparative StudyAxillary brachial plexus block in two hundred consecutive patients.
Two hundred consecutive, minimally-sedated patients presenting for upper limb surgery were audited prospectively to determine the overall clinical success rate, extent of cutaneous neural blockade, reliability and complication rate of each indicator of axillary sheath entry, and degree of patient satisfaction. The axillary sheath was identified, using a 22 gauge, short-bevelled needle, by one of four indicators, whichever was elicited first (paraesthesia, arterial or venous puncture, or tethering by the axillary sheath). Alkalinized mepivacaine 1.2%, 50 ml then was injected. ⋯ Complete anaesthesia distal to the elbow was achieved in 85% of patients. Complications were common, but generally mild and transient: mild acute local anaesthetic toxicity, 3.5%; axillary tenderness and bruising, 12%; and dysaesthesias, 12.5%. Despite this, patient satisfaction was high (97%).