OBSERVATIONS ON EXTRADURAL MORPHINE ANALGESIA IN VARIOUS PAIN CONDITIONS

We report the extradural administration of low-dose morphine in 10 ml of 10 % dextrose (2-3 mg) to 98 adult patients with various types of acute and chronic pain. Extradural morphine injections were given either via a Tuohy needle (single or repeat injection) or via an extradural catheter. Pain relief was evaluated by subjective scoring and by the subsequent need for systemic analgesics. In 56% of patients, pain relief was considered good or excellent, in 24 % it was fair, and in 20%, poor. The best results were after surgery and trauma and in patients with advanced peripheral vascular disease. The analgesia of each dose of extradural morphine lasted for 8 h (mean range 4-36 h). There was no motor, sensory or sympathetic blockade and no respiratory or haemodynamic complications. Dizziness and vomiting occurred in two patients, and urinary retention for about 12 h in three. Recent reports have indicated that effective and prolonged pain relief can be obtained in man by the injection of small doses of morphine or pethidine into either the subarachnoid (Wang, 1978; Samii et al., 1979; Wang, Nauss and Thomas, 1979) or the extradural space (Behar et al., 1979; Cousins et al.