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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This clinical study was designed to assess the results of new preoperative fasting guidelines in which patients are instructed that they must not eat any solid food after midnight, but that they may drink unrestricted amounts of clear fluid until three hours before their scheduled time of surgery. We studied 199 healthy, elective surgical inpatients aged 18-70 yr to determine whether there was any correlation between the ingestion interval or the volume of fluid ingested, with the volume and pH of residual gastric fluid at induction of anaesthesia. Pregnant patients, and those with gastric disorders or who were taking medications that affect gastric motility or secretion, were excluded. ⋯ The remaining 94 patients did not drink because they were scheduled for surgery before 11:00 (n = 51), they did not want to drink (n = 24), or they were advised not to drink by their nurse or surgeon (n = 16). Following induction of anaesthesia, gastric fluid was aspirated through a #18 Salem sump orogastric tube, the volume was recorded and pH was measured with a calibrated pH meter. Patients were divided retrospectively into four groups (in three of which patients ingested fluid) according to the ingestion-induction interval (1.3-3.0 hr, 3.1-5.0 hr, 5.1-8.0 hr, and nothing by mouth after midnight).(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.