British journal of anaesthesia
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A computer controlled infusion device for propofol was used to induce and maintain general anaesthesia in 20 children undergoing minor surgical procedures. The device was programmed with an adult pharmacokinetic model for propofol. During and after anaesthesia, blood samples were taken for measurement of propofol concentrations and it was found that the values obtained were systematically overpredicted by the delivery system algorithm. New pharmacokinetic microconstants were derived from our data which reflected more accurately the elimination and distribution of propofol in a prospective study involving another 10 children.
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We have examined the safety of induced hypotension produced by extradural anaesthesia in patients with medically controlled hypertension. The haemodynamic response to induced hypotension was assessed in 38 non-hypertensive and 31 controlled hypertensive patients. All received extradural anaesthesia to T4 or above which decreased mean arterial pressure to 52 mm Hg and 55 mm Hg in normotensive and hypertensive patients, respectively. ⋯ None developed acute renal failure or stroke. There were three deaths; one of a patient who had hypertension. This suggests that induced hypotension with extradural anaesthesia is a safe technique for patients with medically controlled hypertension undergoing total hip arthroplasty.
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Randomized Controlled Trial Comparative Study Clinical Trial
Propofol sedation for outpatient upper gastrointestinal endoscopy: comparison with midazolam.
The objectives of this study were to assess midazolam and propofol as sedative agents for outpatient gastrointestinal endoscopy, with particular reference to recovery profile, amnesic effects, and haemodynamic state and oxygenation during the procedure. Forty consecutive patients were allocated randomly to two groups. Patients in group I (n = 19) received midazolam 81 (SEM 32) micrograms kg-1; those in group II (n = 21) received propofol 950 (400) micrograms kg-1. ⋯ Oxygen desaturation from baseline was similar in both groups (P less than 0.01). An increase in heart rate and decrease in mean arterial pressure were noted in both groups. Propofol provided more rapid recovery compared with midazolam, but was associated with pain on injection, a short amnesia span, and reduced patient acceptance.
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Comparative Study
Comparison of invasive and non-invasive measurements of continuous arterial pressure using the Finapres.
A comparison was made of arterial pressures measured invasively from a radial arterial cannula and non-invasively from the middle finger using the 2300 Finapres (Ohmeda) during induction and maintenance of anaesthesia. Digital outputs of both pressures were captured directly onto computer hard disk; data recorded during flushing of the arterial line were excluded from analysis. We studied 53 patients undergoing cardiac, major vascular and neurosurgical procedures; 17705 comparisons of systolic, diastolic and mean pressure were analysed. ⋯ However, patient data sets showed marked variability in average pressure differences (invasive minus Finapres) when examined individually or grouped by operation type. Unexplained variations in pressure difference with time and absolute pressure were observed also. Whilst providing useful beat-to-beat information on arterial pressure trends, the Finapres cannot be recommended as a universal substitute for invasive arterial pressure monitoring.