[Long-term intrathecal isobaric morphine therapy]

In order to evaluate long-term intrathecal morphine therapy for cancer pain, whatever its location, 121 patients (80% were ambulatory patients) treated between April 1979 and April 1985 at the Cancer Institute of Montpellier (Centre Paul-Lamarque) were assessed. Morphine was stored in a presternal insulin syringe, protected by a sterile and waterproof dressing. A bolus administration of morphine via a subcutaneous lombo-epigastric subarachnoid catheter was scheduled every 12 h. This "closed" device was opened for refilling in an operating room only. The mean follow-up was 68 days (maximum: 13 months). More than 15,000 intrathecal injections were made. The mean daily amount of morphine required was 2.3 mg (extremes: 0.75 and 21 mg). All patients developed tolerance, requiring an adjustment of morphine dosages every 30 to 45 days. With the isobaric morphine solution, good or very good analgesia was achieved in 82% of patients, even in those suffering from thoracic or otolaryngologic pain. Mechanical complications (catheter coming out of the subarachnoid space in 7.67% of cases, leakage of CSF along the catheter in 9.16% of cases) were related to the exteriorization of the proximal catheter tip. With the exception of errors in manipulation, neither infection nor clinical respiratory depression were noticed. Nausea and vomiting were frequent but resolved spontaneously within a few days. Urine retention (33%) occurred mainly in men over 65 years, after pelvic surgery or radiotherapy. Because of the absence of a defined zone of analgesia, the small volumes required and the "ready for use" preparation, intrathecal isobaric morphine therapy will lead to easy self-administration via an implanted pump in the future.(ABSTRACT TRUNCATED AT 250 WORDS)