Canadian journal of anaesthesia = Journal canadien d'anesthésie
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In spontaneously breathing anaesthetized subjects, we studied a new technique for the measurement of changes in pleural pressure. Seven ASA physical status I patients undergoing general anaesthesia (enflurane 1-2 MAC, nitrous oxide 50%, and oxygen) for minor orthopaedic surgery were studied in the supine position. Changes in oesophageal pressure (delta Pes) were measured by means of a catheter-tip pressure transducer. ⋯ Using the linear regression analysis to characterize the delta Pes/delta Pao relationship, we have developed a different approach for the positioning of oesophageal catheter. After statistical analysis of the observed delta Pes/delta Pao relationship, a "calibration" factor can be used in order to correct the observed slope of the delta Pes/delta Pao relationship to its theoretical value. We conclude that an oesophageal catheter-tip micromanometer can be used in anaesthetized supine patients to measure changes in pleural pressure.
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The pharmacodynamics and pharmacokinetics of a new non-depolarizing neuromuscular blocking agent, Org 9426, were investigated. Ten patients undergoing elective head and neck surgery and anaesthetized with nitrous oxide, halothane and fentanyl, received a bolus dose of Org 9426 (1 mg.kg-1, 3 x ED90). The isometric contractions of the adductor pollicis muscle following ulnar nerve stimulation (0.1 Hz and intermittent TOF) were measured. ⋯ Within 24 h, 33 (37)% of Org 9426 was excreted unchanged in the urine. Metabolites were absent both in plasma and urine. We conclude that the difference in potency between Org 9426 and vecuronium is similar to the difference between their effective concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)
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The use of blood products in 1480 consecutive cases of adult cardiac surgical procedures over a period of 15 mth was studied retrospectively using the database of the Department of Anaesthesia of the Institut de Cardiologie de Montréal. Use of blood products was compared in patients having (1) coronary artery bypass grafting, (2) valvular surgery, (3) or a combination of 1 and 2. First operations were compared with reoperations. ⋯ Repeat CABG was associated with an intermediate exposure to homologous blood products (eight units). Finally, primary and repeat combined procedures, and repeat valve surgery were associated with the greatest exposure to foreign blood products (10, 13 and 10 units respectively). The data presented in this study provide a rational basis for stratification of procedures according to the expected use of blood products, particularly in view of future studies which may be planned to examine the efficiency of blood conservation strategies.
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Case Reports
Patient-controlled analgesia (PCA) using fentanyl in a parturient with a platelet function abnormality.
A term parturient with documented platelet dysfunction presented to the case room for induction of labour. Since this bleeding abnormality contraindicated the use of lumbar epidural analgesia (LEA), we elected to use an iv fentanyl patient-controlled analgesia (PCA) technique for pain relief during labour. ⋯ Mother and neonate tolerated the fentanyl without sequelae. If facilities to monitor the neonate and mother are present, this method of analgesia is useful in those patients where LEA is contraindicated.