COMPARISON OF THE RESPIRATORY EFFECTS OF KETOROLAC AND MORPHINE IN POSTOPERATIVE ANALGESIA

The analgesic and respiratory effects of single, intramuscular doses o f ketorolac trometamol were compared with those of morphine. Sixty-fiv e patients undergoing abdominal surgery or vascular surgery of the low er limbs were entered into this double-blind, parallel-group study. Pa tients were randomly assigned to receive ketorolac 10 mg, ketorolac 90 mg, or morphine 10 mg in the immediate postoperative period. Respirat ory function was assessed by monitoring transcutaneous carbon dioxide pressure (TcPCO2) in all patients and by measuring arterial blood gase s (PaCO2) in those undergoing vascular surgery. A correlation of TcPCO 2 with PaCO2 confirmed the validity of using TcPCO2 as a measure of re spiratory function. Comparable analgesia was seen in all three treatme nt groups. In both ketorolac groups, TcPCO2 decreased and sedation was less than that seen in the morphine group. Increasing the dose of ket orolac from 10 mg to 90 mg did not result in a significant increase in side effects. These data demonstrate that ketorolac, a peripherally a cting nonsteroidal anti-inflammatory drug, has clinical advantages ove r the centrally acting opiate morphine.