Maternal venous (MV), umbilical venous (UV) and umbilical arterial (UA) blood samples were obtained for assay of atracurium, laudanosine and monoquaternary alcohol concentrations in 22 healthy patients undergoing elective Caesarean section under general anaesthesia. At delivery (at a mean time of 8.2 min after atracurium 0.3 mg kg-1), the mean UV concentrations were 103 ng ml-1 (range 44-189 ng...

The use of atracurium in 25 patients undergoing general surgical procedures is described, neuromuscular function being monitored by the "train-of-four" stimuli. An initial dose of atracurium 0.5 mg kg-1 proved to be clinically acceptable, giving good conditions for endotracheal intubation and adequate muscle relaxation for about 40 min. Comparison of the results with those from 15 patients give...

The potency of atracurium was determined in neonates, infants and children during thiopentone-fentanyl-nitrous oxide in oxygen anaesthesia using single dose-response curves. The effective doses producing 50% depression of the first twitch of the train-of-four were significantly lower in neonates and infants than in children (82 and 112 v. 135 micrograms kg-1). Following a standard dose of atrac...

The pharmacokinetics of atracurium, laudanosine and the quaternary alcohol were studied in patients with normal and impaired renal function following intravenous administration of atracurium. Anaesthesia consisted of thiopental, fentanyl, halothane and nitrous oxide in oxygen. Plasma and urine concentrations of the parent compound and its degradation products were measured by high performance l...

Among the non-depolarizing neuromuscular blocking drugs, atracurium appears to be unique in its ability to produce cerebral stimulation in lightly anaesthetized animals. This effect is attributed to the atracurium metabolite, laudanosine. The following studies were performed to determine if pretreatments with the non-depolarizing neuromuscular blockers pancuronium, atracurium or vecuronium woul...

The effects of vecuronium and atracurium on neuromuscular transmission, on the responses of the heart rate to vagal stimulation and on the responses to preganglionic stimulation of the nictitating membrane were compared in the chloralose-anaesthetized cat. Vecuronium was four times more potent than atracurium as a neuromuscular blocking agent, whereas the two compounds had similar potencies in ...

A prospective, randomized, double-blind study was performed in 40 patients (ASA class I-III) treated with atracurium to ascertain whether histamine release caused hemodynamic or cutaneous changes. The treated group of 20 patients was premedicated with the H1 antagonist dimetindene (0.2 mg/kg) and the H2 antagonist ranitidine (1.25 mg/kg); the control group of 20 patients received saline. Six mi...

Atracurium was used to produce neuromuscular blockade in a patient with dystrophia myotonica. Operating conditions were excellent and myotonia was not seen. Sensitivity to atracurium was not seen and spontaneous recovery was not prolonged.

The effect of atracurium on intraocular pressure was studied by comparing it with pancuronium in a randomised controlled trial. The intraocular pressure was measured in patients undergoing cataract surgery before administration of the muscle relaxant, at 1, 3, and 5 minutes after its administration, and at 1 minute after tracheal intubation. Atracurium was found to decrease intraocular pressure...