LOCAL ANAESTHETIC TECHNIQUES FOR PREVENTION OF POSTOPERATIVE

The potential benefits of local anaesthetic techniques in the postoperative period have long been recognized. In a review of early work, Simpson and Parkhouse (1961) pointed out that, in 1935, Capelle irrigated abdominal wounds with local anaesthetic injected through large, curved, hollow needles. These were inserted at the end of the operation and left in place in a manner similar to deep tension sutures. The method was apparently effective, but was not adopted widely because of fear of wound infection and delayed healing. Gerwig, Thompson and Blades (1951) used the same principle when they inserted polyethylene tubes deep to the anterior rectus sheath for wound irrigation, and they noted that patients so treated required only a quarter of the usual amount of morphine. Gius (1940) described the use of para vertebral block with procaine for the treatment of post-operative atelectasis, and Cleland (1949) used "continuous" caudal and extradural analgesia for over 100 abdominal and ano—rectal cases. He claimed that this resulted in normal postoperative respiration and early, painless ambulation. Bonica (1953) used intermittent injections through an indwelling extradural catheter to produce segmental analgesia, and found that this gave complete pain relief and allowed effective ventilation and coughing. Dawkins (1956) preferred to give extradural lignocaine as an infusion. He found that this technique was capable of providing truly continuous analgesia, and pointed out that the use of the word "continuous" is a misnomer when applied to intermittent injections or top-ups of local anaesthetic.