Anaesthesia
-
Cerebral blood flow, cerebral oxygen consumption, lactate and glucose metabolism were measured in 13 patients during anaesthesia with nitrous oxide, oxygen and enflurane 0.5% and after 30 minutes infusion of propofol. The mean blood concentration of propofol was 4.06 micrograms/ml. ⋯ Cerebral oxygen consumption decreased by 18.25%. Changes in the electro-encephalograph were related to the blood levels of propofol.
-
Comparative Study Clinical Trial Controlled Clinical Trial
Intra-ocular pressure changes during induction of anaesthesia and tracheal intubation. A comparison of thiopentone and propofol followed by vecuronium.
Intra-ocular pressure was measured during induction of anaesthesia with propofol (n = 40) or thiopentone (n = 40) followed by vecuronium to facilitate tracheal intubation which was carried out 3 minutes after the administration of relaxant. The average induction doses were 2.15 and 4.83 mg/kg for propofol and thiopentone, respectively. Half the patients in each group received a supplementary dose of the same induction agent (propofol 1.0 mg/kg or thiopentone 2.0 mg/kg) (corrected) prior to intubation. ⋯ Supplementary doses of induction agents before intubation attenuated the increase in intra-ocular pressure. Propofol was significantly more effective in this respect and this group showed the lowest intra-ocular pressure throughout the study period. However, administration of propofol resulted in a 30% incidence of pain on injection and a decrease in systolic arterial pressure of more than 30% in about half the patients.
-
The effects of a bolus injection of propofol on mean intracranial pressure were studied in six adult, comatose patients who had severe head injuries. Propofol 2 mg/kg was given intravenously over 90 seconds when the mean intracranial pressure reached or exceeded 25 mmHg. Arterial blood gas values, heart rate and central venous pressure remained stable at all measurements. ⋯ The mean (SEM) intracranial pressure decreased statistically significantly (p less than 0.05) at 30 seconds and at 1 and 2 minutes, from 25 (3) to 11 (4) mmHg. The cerebral perfusion pressure decreased statistically significantly from 92 (8) mmHg at all measurements (p less than 0.05). The lowest value at 3 minutes was 50 (7) mmHg but in four patients at that time the perfusion pressure was below 50 mmHg.
-
The pharmacokinetics of a constant rate infusion of propofol were studied in 11 patients who received total intravenous anaesthesia for ENT surgery. Alfentanil was administered as an exponentially decreasing infusion using a computer-assisted infusion device with a constant target plasma alfentanil concentration of 300 ng/ml. Propofol was infused at a constant rate of 6 mg/kg/hours. ⋯ Only three data sets were significantly underestimated after the infusion was stopped (mean bias 11.9% (SD 25.5]. The elimination half-life of alfentanil was approximately 75 minutes (SD 21). We conclude that alfentanil does not interfere with the pharmacokinetic profile of propofol but that propofol induces higher plasma alfentanil concentrations than expected.
-
A 30-year-old woman developed severe chest pain while out shopping and was admitted to the delivery suite. She was 38 weeks pregnant with her second child. ⋯ She went into spontaneous labour 30 hours later and was delivered vaginally. This report reviews myocardial infarction in pregnancy and considers the clinical management of this patient.