Dose response studies in elderly patients subjected to epidural analgesia

In 51 men, aged 60-87 years, subjected to lumbar epidural analgesia for transurethral resection of the prostate gland, the relationship between doses of 10, 15 and 20 ml mepivacaine 1.5 with adrenaline 1:200,000 and the extension of analgesia was studied. Three different postures during application of epidural analgesia were investigated (left lateral position, sitting position with the patient turned supine immediately after injection, and the sitting position with the patient turned supine 5 min after injection. The results indicate that posture did not significantly influence the extension of analgesia, which was found to be positively correlated to the volume of mepivacaine, and the segmental dose requirement was positively correlated to the volume injected. It is concluded that transurethral resection of the prostate gland in patients over 60 years old can be performed using mepivacaine 1.5% with adrenaline 1:200,000 injected in the lumbar epidural space. In some cases, doses of 15 and 20 ml provoked an unwanted extension of analgesia, reaching the upper thoracic segments.