[Continuous thoracic epidural fentanyl in postoperative pain control--a comparison of two different dosages]

We evaluate the postoperative pain relief using continuous epidural fentanyl infusion in two different dosages for thoracic and upper abdominal surgeries. A total of 21 ASA class III patients were studied. A thoracic epidural catheter was placed before surgery but pain control was begun when the patients became fully awake and complained of pain in the recovery room. Patients were divided into group A (n = 9) and group B (n = 12). Those in group A were given fentanyl 1.5 micrograms/kg in saline solution as initial dose followed by continuous infusion at a rate of 1 microgram/kg/h for 23 hours. In group B the initial dose and the maintenance dose were respectively 1.0 microgram/kg and 0.5 micrograms/kg/h. Following the initial dose, the intensity of pain was assessed hourly for a total of 24 hours using a visual analogue pain scale with scores from 0 to 10. In group A, the pain scale fell from the baseline level of 7.7 +/- 2.6 to 2.3 +/- 2.0 at the first hour while in group B it fell from 8.9 +/- 1.4 to 4.3 +/- 2.1. The pain scores following continuous infusion in groups A and B were respectively 1.3 +/- 1.5 and 2.9 +/- 1.7. Although the analgesic effect appeared to be better in group A, pain relief was satisfactory in both groups (p less than 0.01). Regarding respiratory depression, there was a greater degree of rise in PaCO2 in group A and some of the patients even had a PaCO2 value above 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)