[Evaluation of the synergism between ketorolac and morphine in the treatment of postoperative pain].

BACKGROUND

The aim of the study is to determine what concentration of ketorolac and morphine administered together i.v. achieve best synergic effect between NSAID antiinflammatory and opioids analgesic properties.

DESIGN

Randomized comparative study was carried out on 180 patients, ASA II-IV, undergoing major general surgery, in an University Clinic.

METHODS

Postoperative pain therapy by i.v. PCA: group 1 morphine 0.75 mg.ml + ketorolac 0.75 mg.ml; group 2 morphine 0.50 mg.ml + ketorolac 1.50 mg.ml; group 3 morphine 0.25 mg.ml + ketorolac 1.50 mg.ml; in saline solution. Initial bolus: 2 ml. Continuous infusion 1.5 ml.h. Demand bolus: 0.2 ml. Lockout time: 30 minutes. Evaluations included: pain intensity (T0, T3, T18); total amount of infused drugs (T18); number of valid demands and attempts (T18); amount of autoadministered analgesic drugs in percent of highest available amount (T18); side effects (T18); patient's judgment.

DATA ANALYSIS

ANOVA and Student's "t"-test.

RESULTS

A statistically significant reduction of pain intensity was found after 3 and 18 hours in the three groups, no differences were found among the groups. Group 2 required an amount of autoadministered drugs significantly lower than other groups. Rare side effects. Patient's judgment was generally positive.

CONCLUSIONS

Results suggest a greater synergetic effect between morphine and ketorolac in concentrations used in group 2.