THE ADDITION OF CONTINUOUS INTRAVENOUS-INFUSION OF KETOROLAC TO A PATIENT-CONTROLLED ANALGESIC MORPHINE REGIME REDUCED POSTOPERATIVE MYOCARDIAL-ISCHEMIA IN PATIENTS UNDERGOING ELECTIVE TOTAL HIP OR KNEE ARTHROPLASTY

This double-blind randomized trial assessed the effect of adding an in travenous continuous infusion of ketorolac to a patient-controlled ana lgesia (PCA) morphine regimen on analgesia, heart rate, arterial blood pressure, and postoperative myocardial ischemia. Patients having elec tive total hip or knee replacement were randomized to receive ketorola c 30 mg bolus, followed by an infusion of 5 mg/h for 24 h or placebo. All patients had access to PCA morphine (20 mu g/kg bolus, with a lock out of 6 min). Patients were monitored for pain visual analog scale, b lood pressure, heart rate, and ST segment depression via a continuous Holter monitor. ST depression of 1 mm 60 ms after the J point was cons idered significant if it lasted more than I min. There was no differen ce in demographics, risk factors, or cardiac medications between the g roups. Ketorolac-treated patients had significantly better pain contro l at 2, 6, and 24 h. There was significant morphine sparing at all tim es after 3 h. There was no difference in the number of ischemic events between the groups. The ischemic episodes of the patients who receive d ketorolac occurred at slower heart rates (97 +/- 15 vs 114 +/- 16 bp m, P = 0.001) than those of patients in the placebo group. The duratio n of ST depression was shorter in ketorolac-treated patients (24 +/- 3 5 vs 76 +/- 95 min, P < 0.05). All ST depressions were clinically sile nt. Logistic regression of factors predicting ischemia included the us e of calcium channel blockers and low pain score. These results sugges t that analgesia with ketorolac reduces the duration of ischemic episo des in the first 24 h postoperatively.