A New Method for Providing Continuous Extradural Analgesia.

Continuous extradural analgesia by means of repeated doses of local analgesic drugs through a catheter placed in the extradural space is now widely used in this country, both for the production of surgical analgesia and for the relief of pain. Using the caudal route, labour can be conducted painlessly, and by simply increasing the dosage the analgesia can be extended to cover a Caesarean section should this be necessary (Hingson, Cull and Benzinger, 1961). Using the thoracic approach, Simpson (1961) produced a segmental extradural block which allowed patients with upper abdominal operations to have a completely pain-free postoperative course. Segmental block has been used with success in the treatment of chest injuries. Extradural analgesia will produce complete relief of pain compared with the relative analgesia of narcotic analgesics. The ability to cough without pain is of great value to the patient after operation and to the patient with a chest injury. The principal disadvantage of the method in the absence of a long-acting analgesic drug is the necessity for frequent "topping-up" doses. Many attempts have been made to simplify the technique of "topping-up". Simpson and Salt designed the Oxford chuck (1961) whose inner chamber into which the extradural catheter was fed is protected by a sterile replacement cap. Cole described a 50-ml sterile syringe filled with analgesic solution, and enclosed in a plastic envelope., through which the plunger of the syringe could be depressed. Bum (1963) used a sterile polythene bag containing analgesic, which was fed into the extradural space by gravity. This paper describes the use of a plastic disposable syringe for the production of continuous extradural analgesia.