The efficacy of intravenous atropine in abolishing the nasal irritation of chlormethiazole was assessed. Forty elderly patients undergoing transurethral resection of prostate under spinal anaesthesia were studied. One ml of either atropine sulphate (0.6 mg) or normal saline was administered intravenously in a double-blind fashion 10 minutes prior to infusion of 0.8% chlormethiazole edisylate. A loading infusion of 5 ml.min-1 of the chlormethiazole solution was followed by a variable rate of infusion in order to maintain a predetermined state of sedationi.e. where the patient lapsed into sleep but was easily awakened to obey commands. Sneezing was the commonest side-effect occurring in 45 % and 70% of patients in atropine and saline groups respectively. This was not effectively abolished by IV atropine in incremental doses of 0.6 mg up to 1.8 mg. Because of the sneezing and restlessness, four patients in the atropine group required general anaesthesia to improve operating conditions. These side-effects of chlormethiazole may limit its use as a sedative for surgery in this elderly age group.

In a prospective double-blind study, single-dose lumbar epidural blockade was administered to 60 healthy patients undergoing lower abdominal surgery, the patients lying in the lateral position only during the time of injection of the local anaesthetic. Solutions used were bupivacaine HCI 0.5%, lignocaine HCI 2% and Iignocaine-bupivacaine mixtures in the ratios of 1:3, 1:1 and 3:1 by volume. Data were pooled and analysed for the effects of posture on epidural blockade. Using skin temperature as a criterion of sympathetic blockade, onset of blockade was more rapid and there was more prolonged blockade on the dependent side. Initial onset of sensory blockade was faster on the dependent side by 1 minute and 3.1 minutes for partial and complete blockade, respectively. Mean duration of sensory blockade was longer in the dependent dermatomes for partial (14, SD 7. minutes, T6-L4) and complete blockade (20, SD 6, minutes, TS-L3) respectively. Initial onset of complete motor blockade was 5 minutes more rapid on the dependent side, with mean myotome score consistently greater at all time intervals on the dependent side. Our study therefore suggests that a more efficacious sensory and motor blockade could be achieved by lying the patient on the operative side during the administration of the epidural and injection of the local anaesthestic solution close to the operative dermatomes.