We aimed to compare the efficacy of fluid preloading with two recently recommended fluid-vasopressor regimens for maintaining blood pressure during subarachnoid anaesthesia in the elderly. Sixty elderly patients requiring surgery for traumatic hip fractures received subarachnoid anaesthesia using 0.05 ml/kg of 0.5% heavy bupivacaine. Hypotension, i.e. systolic arterial pressure <75% of baseline, was prevented or treated by: A—normal saline 16 ml/kg plus intravenous ephedrine boluses (0.1 mg/kg); B—normal saline 8 ml/kg plus intramuscular depot ephedrine (0.5 mg/kg); or C—Haemaccel 8 ml/kg plus metaraminol infusion. Systolic arterial pressure and heart rate were recorded using custom-written computer software (Monitor, version 1.0). Systolic arterial pressure decreased in all groups after five minutes (P<0.001). Decreases were greatest in group A (P<0.05). Heart rate increased by 7% group A and decreased by 9% in group C (P<0.05). During the first hour, hypotension was present for 47%, 25% and 20% of the time in groups A, B and C respectively and overcorrection of systolic arterial pressure occurred in 19% of the time in group C. We conclude that treatment A was inadequate in preventing hypotension. Treatments B and C were more effective but were associated with an increased heart rate and overcorrection of systolic arterial pressure respectively.

Low dose mivacurium less effective than succinylcholine in electroconvulsive therapy is Purpose: To compare the efficacy of low dose (LD) mivacurium (0.08 mg'kg -I) with LD succinylcholine (0.5 mg-kg -I) in modifying seizure activity during electroconvulsive therapy (ECT). Partial muscle relaxation is used in ECT to prevent violent muscle contractions. Current practice is to use LD succinylcholine which has several undesirable side effects. Method: Sixteen depressed, but otherwise healthy, patients, aged 27-67 yr were studied. In a randomized, double-blind, cross-over study, either LD mivacurium or LD succinylcholine was given at consecutive ECTs 120 and 30 sec respectively before inducing ECT. Neuromuscular blockade following mivacurium was not reversed. Seizure modification was scored -0 = no seizure activity, I = over-modified, 2 = desired level, 3 = under-modified, 4 = unmodified. Duration of seizures, time to first breath and adequate ventilation, ability to protrude tongue and sustain hand grip for five seconds were recorded. Paired t-tests and Wilcoxon matched pairs test were used to compare data. P < 0.05 was considered significant. Results: Seizure modification was better (mean (range)) after succinylcholine 2.06(I-3) than after mivacurium 2.56(2-4) (P < 0.05). Mivacurium was unsatisfactory in eight cases compared with two cases after succinylcholine. The study was terminated early because of unsatisfactory seizure control. Clinical assessments of recovery from both relaxants were similar. Conclusion: Low dose mivacurium is unsuitable for use in ECT.