A simple safe method for continuous infusion epidural analgesia in obstetrics

Continuous infusion epidural anaesthesia may reduce the risks of hypotension, high spinal block and intravenous injection associated with repeated bolus injections. However, controlling the rate of a simple infusion is difficult and infusion pumps are expensive and bulky. We describe a method for continuous infusion epidural anesthesia using a 6 ml/hr capillary infusion device (Intraflo CFS-06F Sorenson Research Co., Salt Lake City, Utah) and bupivicaine 0.25 per cent. In a study of 50 patients, 35 (70 per cent) had adequate pain relief with the infusion alone for a mean time until delivery of 5 hours (range 2 to 13 hours). A further 11 patients (22 per cent) required only one top-up for the second stage of labour after a mean pain-free time of 5.4 hours (range 1.5 to 9.7 hours). There were no maternal or foetal complications related to the technique of continuous infusion used. No block went higher than the ninth thoracic dermatome at any time.