Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Assessment and accurate replacement of blood loss during primary craniosynostosis repair is difficult due to patient size and surgical technique. Eighty-five charts of all patients undergoing primary craniosynostosis repair over a 15-year period were reviewed to determine blood loss and to assess blood transfusion practices both intraoperatively and postoperatively. Blood loss was calculated on the basis of estimated red cell mass (ERCM). ⋯ Intraoperatively, 70 per cent of all patients were appropriately managed with respect to blood transfusion. Postoperatively only 29 per cent of patients receiving transfusions were transfused appropriately. At our institution, intraoperative blood transfusion practices are appropriate, but postoperative transfusions are frequently unnecessary.
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Two cases of cardiac tamponade caused by dissections of the ascending thoracic aorta are described. Despite uneventful induction of anaesthesia one patient exsanguinated following sternotomy and release of pericardial tamponade as the resulting increase in blood pressure caused aortic rupture. ⋯ The anaesthetic management of a patient with cardiac tamponade is directed towards maintaining cardiac filling pressures and contractility. When the tamponade is released the sudden increase in cardiac output and blood pressure may cause the already weakened aorta to rupture.
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Randomized Controlled Trial Clinical Trial
Atropine-neostigmine mixture: a dose-response study.
The dose-response relationship and the doses of atropine required to prevent neostigmine from lowering heart rates below baseline in 50 per cent (ED50) and 95 percent (ED95) of patients after antagonism of pancuronium-induced neuromuscular blockade were determined in 70 patients with neostigmine-atropine mixtures. Neostigmine 0.04 mg.kg-1 (group A, n = 35) or 0.06 mg.kg-1 (group B, n = 35) was randomly mixed with one of seven doses of atropine (ranging from 0.014 to 0.04 mg.kg-1) in group A and from 0.02 to 0.04 mg.kg-1 in group B), with dose-response curves for atropine being constructed for both groups 5 and 10 min after injection of the mixture. These dose-response curves were found to be parallel in both groups. ⋯ The estimated ED50 doses of atropine in groups A and B at 5 min were 0.031 and 0.033 mg.kg-1 respectively, and at 10 min the ED50 doses were 0.037 and 0.037 mg.kg-1 respectively. The calculated ED95 doses of atropine in groups A and B at 5 min were 0.05 and 0.046 mg.kg-1, and at 10 min the ED95 doses were also similar, being 0.06 and 0.055 mg.kg-1 respectively. Under the conditions employed in this study it would seem that in order to prevent late reductions in heart rates, the appropriate doses of atropine when used with neostigmine should be greater than that commonly used.
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The haemodynamic responses to laryngoscopy and intubation after induction of anaesthesia with thiopentone alone or in combination with 1.5 mg.kg-1 lidocaine and/or 1.5 or 3.0 microgram.kg-1 fentanyl were measured in 150 patients over 64 years of age to determine whether lidocaine, fentanyl or both lidocaine and fentanyl attenuated the pressor response. Fentanyl reduced the rises in systolic, diastolic and mean arterial pressures, heart rate, and rate pressure product and lidocaine decreased the rises in arterial blood pressure and rate pressure product (P less than 0.05). Fentanyl decreased the incidence of marked fluctuations in haemodynamic variables, often seen in geriatric patients (P less than 0.05). ⋯ Fentanyl-treated patients had a higher incidence of hypotension (P less than 0.05). Respiratory depression developed in only one per cent of the fentanyl-treated patients. Both lidocaine and fentanyl are recommended adjuncts to induction of anaesthesia with thiopentone in geriatric patients.