Effect of injected volume and speed of injection on the spread of spinal anaesthesia with isobaric amethocaine
McClure, J.H.; Brown, D.T.; Wildsmith, J.A.
British Journal of Anaesthesia 54(9): 917-920
1982
ISSN/ISBN: 0007-0912 PMID: 7115603 Document Number: 186596
Amethocaine 10 mg in isobaric solution was injected intrathecally in 40 patients. Three volumes (1, 2 and 4 ml) of injection and 2 rates of injection (1 ml/5 s and 1/ml 10 s) were studied. Small volumes (1 and 2 ml) of the more concentrated solutions (1 and 0.5%) produced predictable blockade with spread restricted to the lower thoracic segments. Increasing the volume had little effect on the mean height of spinal blockade, but blockade was less predictable. Slowing the speed of injection of the largest volume (4 ml) partly counteracted this effect.