British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Reduction in standard MAC and MAC for intubation after clonidine premedication in children.
We examined the relative effects of different doses of oral clonidine on the MAC for endotracheal intubation (MACEI) and the MAC for skin incision (MAC) in children. We studied 90 children (15 in each group) (age range 2-8 yr, weight 10-27 kg, height 89-124 cm) who received one of three preanaesthetic medications: placebo (control), oral clonidine 2 micrograms kg-1, or oral clonidine 4 micrograms kg-1 100 min before anaesthesia. Anaesthesia was induced and maintained with sevoflurane in oxygen and air without i.v. anesthetics and neuromuscular relaxants. ⋯ Mean (SD) MACEIs of sevoflurane were 2.9 (0.1)%, 2.5 (0.1)% and 1.9 (0.1)% (P < 0.05), and MACs were 2.3 (0.1)%, 1.8 (0.1)% and 1.3 (0.1)% (P < 0.05), respectively, in control, clonidine 2 micrograms kg-1 and clonidine 4 micrograms kg-1 groups. The MACEIs and MACs decreased dose-dependently. The MACEI/MAC ratio (1.4) was not affected by clonidine.
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Randomized Controlled Trial Comparative Study Clinical Trial
Intravenous amiodarone or magnesium sulphate is not cost-beneficial prophylaxis for atrial fibrillation after coronary artery bypass surgery.
Our aims were to examine whether the administration of amiodarone or magnesium sulphate after coronary artery bypass graft surgery (CABG) could reduce the occurrence of atrial fibrillation, and to identify the risk factors associated with atrial fibrillation after CABG. Patients scheduled for elective CABG (n = 155) were allocated randomly, in a controlled double-blind study, to receive immediately after surgery a 72-h infusion of amiodarone (900 mg per 24 h), magnesium (4 g per 24 h) or placebo (0.9% NaCl; 50 ml per 24 h) intravenously. A 72-h Holter ECG was recorded concomitantly. ⋯ Variables associated with the onset of atrial fibrillation were older age (odds ratio 1.9) and a plasma magnesium concentration at 24 h of less than 0.95 mmol litre-1 (odds ratio 6.7). Postoperative administration of amiodarone reduced the occurrence of atrial fibrillation after elective CABG surgery, but was associated with a longer duration of cardiovascular instability and longer need for intensive care; magnesium prophylaxis had no effect. Advanced age and a low plasma magnesium concentration are risk factors for postoperative atrial fibrillation.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of remifentanil compared with fentanyl on intraocular pressure after succinylcholine and tracheal intubation.
Rapid sequence induction using succinylcholine is associated with an increase in intraocular pressure (IOP). This may lead to loss of ocular contents in open globe injuries. No method has previously been shown to prevent this increase in IOP. ⋯ Forty-five patients were randomized blindly to receive remifentanil 1 microgram kg-1, fentanyl 2 micrograms kg-1 or placebo 1 min before thiopental, succinylcholine and tracheal intubation. IOP and haemodynamic variables were measured before, 1 min after the test solution, 30 s after thiopental, 30 s after succinylcholine, immediately after intubation and then every 3 min for 9 min. Remifentanil obtunded the increase in IOP after succinylcholine and intubation, so it could be suitable for use in open globe injuries.
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Epiglottitis in the adult can be fatal and should be treated with the same degree of concern and suspicion in respect of airway patency as in children. We present three cases of adult epiglottitis in which the airway was lost prior to or during the intervention of an anaesthetist. We suggest that an emphasis on conservative management is distracting and belies the serious nature of this disease.
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It is mostly acknowledged that 'normal' or 'healthy' ageing of the cardiovascular system is distinct from the increasing incidence and severity of cardiovascular disease with advancing age (e.g. hypertension, ischaemic heart disease and congestive heart failure). It is also recognized that chronological and biological age may differ considerably. Nevertheless, even in the absence of overt coexisting disease, advanced age is always accompanied by a general decline in organ function, and specifically by alterations in structure and function of the heart and vasculature that will ultimately affect cardiovascular performance. ⋯ On the basis of various clinical studies and observations, it must be concluded that advanced age is an independent predictor of adverse perioperative cardiac outcome. It is to be expected that the aged cardiovascular risk patient carries an even higher perioperative cardiac risk than the younger cardiovascular risk patient. Although knowledge of the physiology of ageing should help reduce age-related complications, successful prophylaxis is hindered by the heterogeneity of age-related changes, unpredictable physiological and pharmacological interactions and diagnostic difficultie