J Korean Pain Soc.  1994 Nov;7(2):188-192.

The Effect of Low Dose Bupivacaine on Epidural Morphine Analgesia for Postoperative Pain

• Ha HS
• Park YC
• Kim HK
• Baik SW
• Chung KS

Abstract

Recently, epidural morphine has been administrated to decrease patients systemic stress responses such as: suffers, endocrine responses and impairment of pulmonary function, etc. Epidural morphine provided excellent analgesic effect, but incomplete sensory blockade as compared to epidural local anesthetics, which has sympathetic blockade effect and tachyphylaxis. Therefore, the authors surmised that low dose bupivacaine on low dose epidural morphine improved postoperative pain with greater sensory analgesia than epidural morphine alone. The effect of low dose bupivacaine on epidural morphine analgesia for postoperative pain was evaluated in seventy patients. They were physical status I-III by ASA classification. Patients were randomly divided into 2 groups and they were administrated morphine 2.5 mg only (group I), morphine 2.5 mg plus 0.125% bupivacaine (group II) through epidural catheter I hour before the end of the operation. During postoperative second days, their analgesic effects were evaluated by visual analogue scale (0-10). Side effects were also evaluated. The results were as follows, 1) On the day of the operation, VAS score showed significant differences between two groups (morphine group 3.20 +/- 0.16, morphine plus bupivacaine group 2.77 +/- 0.08; p < 0.05). 2) On the postoperative and second day, there were no statistical differences between the groups according to VAS score. 3) The incidence of pruritus, nausea, and vomiting were no differences in both groups. 4) None of the patients showed objective sedation or a low respiratory rate (< l0 bpm). We concluded that epidural administration of low dose bupivacaine on the epidural morphine analgesia was an effective method to decrease postoperative pain with little change in frequencies of side effects compared to epidural morphine alone.

MeSH Terms

Analgesia*
Anesthetics, Local
Bupivacaine*
Catheters
Classification
Humans
Incidence
Morphine*
Nausea
Pain, Postoperative*
Pruritus
Respiratory Rate
Tachyphylaxis
Vomiting
Anesthetics, Local
Bupivacaine
Morphine