It was the aim of this placebo-controlled study to evaluate the
analgesic efficacy of the NASAID
carprofen and the pure m-agonist levomthadone over a five-day postoperative evaluation period in dogs with fractures of the humerus or the femur (
n = 30).
Pain and sedation evaluation was carried out with a visual analogues system (VAS) and with the aid of a numerical estimation scale(NRS). The degree of lameness, the
pain treshhold, the
glucose and
cortisol concentration curves as well as the respiration and heart rate and the systolic blood pressure were used as further
pain indicators and to identify
drug side effects. The levomethadon group displayed the lowest degree of
pain on postoperative examination on the first day. On days 2 to 5, the
carprofen group showed the lowest degree of
pain in comparison to the placebo group. The levomethadon- and the
carprofen group showed no statistically proven differences from day 2 on. Due to great variations in the
pain scores and comparatively high median
pain score especially on the first day of this study, the efficacy of all
analgesics evaluated here must be regarded as insufficient in many cases. Only the parameter
nociceptive pain treshhold showed a little, the degree of lameness, the
glucose and
cortisol levels showed no close correlation to the VAS and NRS
pain scores and were therefore of little usefulness as
postoperative pain indicators. No relevant clinical side effects caused by the used
analgesics were detected in the kidney, the liver, the gastrointestinal tract and the circulatory system in this study. Rather, traumatically induced elevation of
enzyme levels improves or normalised until the 5th day of the study. In addition, no negative effect on wound healing was noted, especially for
carprofen. Therefore, the evaluated
analgesics seems to be adequate for
postoperative pain therapy also in fracture patients (
trauma patients). However, the efficacy of all
analgesics evaluated here must be regarded as insufficient in many cases.