EFFECT OF INTERCOSTAL NERVE BLOCKADE DURING OPERATION ON LUNG FUNCTION AND THE RELIEF OF PAIN FOLLOWING THORACOTOMY

The use, during operation, of intercostal nerve blocks with lignocaine and bupivacaine for the relief of pain following thoracotomy was assessed in 138 patients. Irrespective of the method used to evaluate efficacy, it was not possible to demonstrate a lasting effect of clinical significance favouring either local anaesthetic agent. This form of treatment, although free from serious side effects, had no beneficial effects on lung function and is not recommended for the relief of pain following surgery. In a previous study from Belfast, Pandit, Galway and Dundee (1973) found that thoracotomy per se was a potent cause of acidosis after operation, and that patients subjected to such operations were unusually sensitive to parenteral analgesics. As an alternative approach to the use of opiates in the relief of pain following surgery, intercostal nerve blockade has been attempted in the past, using local anaesthetic solutions such as dolamine (Graham, Seldon and Priestley, 1949), efocaine (Deaton and Bradshaw, 1952), lignocaine 1 % in dextran (Loder, 1960) and carbocaine (Telivuo, 1963, 1964; Moore, Bridenbaugh and Bridenbaugh, 1969) to provide analgesia with minimal respiratory depression. The present investigation is an assessment of the efficacy of intercostal nerve block as a means of pain relief after surgery, in which the long-acting agent bupi-vacaine has been compared with lignocaine and also with a "control " series in which no intercostal block was carried out. The study is divided into two parts, one dealing with the production of anal-gesia and its side effects, the second with lung function studies. PATIENTS AND METHODS One hundred and thirty-eight patients having either an antero- or a posterolateral thoracotomy were studied. Patients presenting for cardiac surger