MOOD DURING EPIDURAL PATIENT-CONTROLLED ANALGESIA WITH MORPHINE OR FENTANYL

Background: Mood states during epidural opioids are not known. The aut hors studied the change in mood during the 48-h period of epidural mor phine and epidural fentanyl in 47 patients after elective hip or knee joint arthroplasty. Methods: An epidural catheter was inserted at the L2-L3 or L3-L4 interspace. Anesthesia was induced with thiopenthal and maintained with isoflurane and nitrous oxide. One hour before the con clusion of the operation, patients received an epidural bolus injectio n of 2 mg morphine (n = 23) or 100 mu g fentanyl (n = 24), followed by the same opiate (125 mu g/ml morphine or 25 mu g/ml fentanyl) epidura lly delivered by a patient-controlled analgesia (PCA) pump in the post operative period for 48 h. Mood was assessed using the bipolar form of the Profile of Mood States before operation and 24 h, 48 h, and 72 h after operation. Results: There was no significant difference in pain intensity between the groups during epidural PCA. Mood states became m ore positive over time in the patients who received morphine (P < 0.01 at 48 h) and negative in those who were given fentanyl (P < 0.01 at 2 4 and 48 h, respectively) compared with those before the operation, an d they were more positive in the morphine than in the fentanyl group a t 24 h, 48 h (P < 0.05), and 72 h (P < 0.01). Patients in the morphine group were more composed, agreeable, elated, confident, energetic, an d clearheaded than were those in the fentanyl group (P < 0.05). There was no correlation between mood scores and pain scores in either group . There was an inverse correlation at 48 h between mood scores and pla sma fentanyl concentrations (r = -0.58, P < 0.05). Conclusion: Mood st ates are significantly more positive during epidural morphine PCA than they are during epidural fentanyl PCA.