Postoperative extradural analgesia following thoracic surgery: a feasibility study.

The feasibility of providing postoperative analgesia using thoracic extradural blockade following thoracotomy has been assessed. Extradural block was produced by intermittent injections of 0.5% bupivacaine with adrenaline 1:200,000 or a continuous infusion of 0.25% or 0.125% bupivacaine. The only toxic symptom was drowsiness which was most frequent after a continuous infusion of 0.25% bupivacaine and with arterial plasma bupivacaine concentrations above 1.5 mug/ml. Arterial hypotension was a troublesome complication with all techniques although stability of arterial pressure was more easily achieved with a continuous infusion technique. However, this produced a high incidence of urinary retention. Practical aspects and effectiveness of providing extradural analgesia in patients following thoracotomy are discussed.