To the Editor:—

We read with interest the report by Norman et al.  on preemptive analgesic effect of ketorolac. 1The authors observed that for 48 patients undergoing ankle fracture surgery that 30 mg of intravenous ketorolac administered before tourniquet inflation offered a better analgesia than after tourniquet inflation at 2 and 4 h after surgery. Can we conclude that it is preemptive analgesia? The effect of ketorolac is mainly peripheral and the tourniquet inflation is probably an adequate technique to compare pre- and postoperative administration. However, the benefit between the two administrations is short-lived (4 h after surgery) and totally compatible with the effect of a single dose of ketorolac. Because preemptive analgesia has to do with limitation of nervous system sensitization, 2these results (similar to previous one 3,4) do not support a preemptive analgesic effect. Rather, they suggest that preoperative administration of nonsteroidal antiinflammatory drugs may reduce or delay the development of peripheral inflammation and therefore improve immediate postoperative analgesia. This effect is transient and vanishes a few hours after surgery, which is totally different from preemptive analgesia observed after some studies using ketamine 5or local anesthetic. 6,7 

1.
Norman PH, Daley MD, Lindsey RW: Preemptive analgesic effects of ketorolac in ankle fracture surgery. A nesthesiology 2001; 94: 599–603
2.
Coderre TJ, Katz J, Vaccarino AL, Melzack R: Contribution of central neuroplasticity to pathological pain: review of clinical and experimental evidence. Pain 1993; 52: 259–85
3.
Fletcher D, Zetlaoui P, Monin S, Bombart M, Samii K: Influence of timing on the analgesic effect of intravenous ketorolac after orthopedic surgery. Pain 1995; 61: 291–7
4.
Rogers JEG, Fleming BG, Macintosh KC, Johnston B, Morgan-Hughes JO: Effect of timing of ketorolac administration on patient-controlled opioid use. Br J Anaesth 1995; 75: 15–8
5.
Menigaux C, Fletcher D, Dupont X, Guignard B, Chauvin M: The benefits of intraoperative small-dose ketamine on postoperative pain after anterior cruciate ligament repair. Anesth Analg 2000; 90: 129–35
6.
Pasqualucci A, De Angelis V, Contardo R, Colo F, Terrosu G, Donini A, Pasetto A, Bresadola F: Preemptive analgesia: Intraperitoneal local anesthetic in laparoscopic cholecystectomy: A randomized, double-blind, placebo-controlled study. A nesthesiology 1996; 85: 11–20
7.
Gottschalk A, Smith DS, Jobes DR, Kennedy SK, Lally SE, Noble VE, Grugan KF, Seifert HA, Cheung A, Malkowicz SB, Gutsche BB, Wein AJ. Preemptive epidural analgesia and recovery from radical prostatectomy: A randomized controlled trial. JAMA 1998; 279: 1076–82