British journal of anaesthesia
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To investigate the effects of propofol on small vessels, we have measured changes in diameter and blood flow in microcirculatory venules and arterioles. Studies were carried out in the dorsal skinfold chamber of hamsters by intravital fluorescence microscopy. A bolus injection of propofol 25 mg kg-1 dilated small and collecting venules by a mean value of 18% and arterioles by 13%. ⋯ Therefore, propofol and Intralipid induced venodilatation and enhanced blood flow after bolus administration. After 4 h, despite dilatation in both groups, only post-capillary venules showed enhanced blood flow. These observations suggest redistribution of blood flow after prolonged administration of propofol.
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We describe the successful use of the short-acting, non-depolarizing neuromuscular blocking agent, mivacurium, in a patient with myotonic dystrophy. Increased sensitivity to mivacurium was demonstrated using train-of-four monitoring, with a single dose of mivacurium providing adequate block for 90 min of surgery. Spontaneous recovery appeared prolonged with a recovery index (25-75% T1) of 10 min and a recovery time (5-95% T1) of 30 min. The use of reversal agents and anticholinergic agents was avoided.
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Clinical Trial
Double lung transplantation without cardiopulmonary bypass: arterial to end-tidal carbon dioxide partial pressure differences.
Bilateral lung transplantation without cardiopulmonary bypass consists of two sequential single lung transplantations. Variations in ventilatory status during the procedure led us to study the (PaCO2-PE'CO2) gradient to see if PE'CO2 might reflect PaCO2. The gradient was studied in 14 patients at six times during operation. (PaCO2-PE'CO2) (kPa) was mean 1.97 (SD 0.7) after induction, 3.2 (1.4) during single lung ventilation, 1.9 (1.1) after clamping of the contralateral pulmonary artery, 2.96 (1.6) after ventilation and vascularization of the first transplant and the remaining native lung, 0.99 (0.8) during single lung ventilation with the first transplant and 1.3 (0.8) during ventilation of both transplants. With ventilation by the allograft lung(s) alone, the small (PaCO2-PE'CO2) value demonstrated improvement in ventilatory status, enabled PaCO2 to be assessed by PE'CO2 and demonstrated efficiency of the grafts.
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We investigated the validity of the abbreviated mental test (AMT) as a guide to the diagnosis of delirium in 100 patients aged more than 65 yr. Patients were assessed using the AMT on the day before and on the third day after operation. ⋯ Patients who developed delirium had a greater decline in AMT score (mean 2.7 (SD 0.9)) than patients who did not develop delirium (0.7 (1.0)) (P < 0.001). The sensitivity and specificity of a decline in AMT score of 2 or more points after surgery for diagnosis of postoperative delirium were 93% and 84%, respectively.
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We have examined the raw EEG activity and auditory evoked responses (AER) in 35 children, aged 3 days to 13 yr (median 1.5 yr), undergoing general anaesthesia for routine surgery. Binaural stimuli were presented at a frequency of 6.12 Hz and the EEG was recorded and stored using the Northwick Park auditory evoked response software. ⋯ In children less than 2 yr, regular artefact activity was superimposed on the background EEG which was at the same frequency as the instantaneous heart rate and which was often identifiable as the ECG. We conclude that the AER may be unreliable in children less than 2 yr of age, and modification of current methodology may be required if this technique is to become useful in paediatric anaesthetic practice.