Objective: To assess the efficacy of sustained postoperative intramuscular ketorolac tromethamine (Toradol) at analgesic levels in the augmentation of acute, random-pattern skin flaps in rat.
Design: Prospective, randomized, placebo-controlled, animal trial.
Setting: Animal research laboratory, School of Medicine, Oregon Health Sciences University, Portland.
Subjects: Forty-four adult male Sprague-Dawley rats (260 to 280 g).
Interventions: Twenty-two treatment animals underwent modified McFarlane random-pattern skin flaps followed immediately by intramuscular loading doses of ketorolac. Treatment animals were then maintained on a regimen of intramuscular ketorolac using a three times a day dosing schedule for 14 days postoperatively. Twenty-two control animals underwent identical modified McFarlane random-pattern skin flaps and were given equivalent volumes of intramuscular saline on the same dosing schedule for the 14-day treatment period.
Main outcome measures: Postmortem measurements of skin flap ischemia (expressed as a percentage of total flap surface area) were performed for both treatment and control animals by three independent, non-blinded observers using the acetate tracing technique. Both pooled and individual data were statistically analyzed using personal computer software.
Results: Forty-three of the 44 animals successfully completed the experimental trial. One animal in the treatment group died on postoperative day 3 of unknown causes. During the study period, one postoperative hematoma was detected in both the treatment and control groups. The mean percentage of skin flap ischemic necrosis observed in control animals (35.4%) was consistently less than that measured in the treatment group (36.4%). However, the difference in ischemic flap necrosis between control and treatment groups was not statistically significant (P = .6919).
Conclusions: Comparatively high-dose intramuscular ketorolac failed to augment acute, random-pattern skin flap survival in rat when initiated in the immediate postoperative period. Complications of prolonged, intramuscular ketorolac were not observed in this trial. Further studies using preoperative initiation of drug therapy may help to clarify the true efficacy of ketorolac in flap augmentation.