Preoperative Small-Dose Ketamine Has No Preemptive Analgesic Effect in Patients Undergoing Total Mastectomy

Lack of a pre-emptive effect of low-dose ketamine on postoperative pain following oral surgery

“…23 Thirdly, Hoffmann et al have recently suggested that liposolubility could be a factor influencing the efficacy of ketamine on postoperative pain when concomitantly administered with opioids. 24 This is in accordance with the findings of Aida et al who have shown a significant reduction of postoperative pain compared with a control group when ketamine was administered in combination with morphine, 25 whereas other studies combining ketamine with sufentanil, 9 or alfentanil 11 did not show a preventive effect on postoperative pain. A possible explanation is competition for active blood barrier transport proteins due to lipophilicity of ketamine and alfentanil or sufentanil, or intracellular differences in phosphorylation associated with specific opioid-ketamine combination.…”

“…In the studies of Adam et al, 9 Dahl et al, 11 and Mathisen et al, 12 a single dose of iv ketamine was administered either before surgery, or after surgery. There was no evidence of a pre-emptive effect when ketamine was administered before surgery, and the analgesic effect of ketamine when administered at the end of surgery was short-lasting and failed to produce a significant opioid-sparing effect.…”

“…In the study of Adam et al, a bolus dose of 150 µg·kg -1 ketamine induced in the postincisional group a short-lasting analgesic effect without significant opioid-sparing effect after mastectomy. 9 We used a ketamine dose two times larger than that used by Adam et al without a positive effect. On the other hand, in the study of Dahl et al, 11 the ketamine dose after hysterectomy was 400 µg·kg -1 , almost three times larger than in the study of Adams et al with a subsequent similar pre-emptive effect.…”

“…On the other hand, in the study of Dahl et al, 11 the ketamine dose after hysterectomy was 400 µg·kg -1 , almost three times larger than in the study of Adams et al with a subsequent similar pre-emptive effect. 9 Although a larger dose of ketamine might have produced a clinically important analgesic effect, the well known dose-related psychomimetic effects of ketamine limit its clinical usefulness at higher doses. 23 Thirdly, Hoffmann et al have recently suggested that liposolubility could be a factor influencing the efficacy of ketamine on postoperative pain when concomitantly administered with opioids.…”

“…Some studies have documented an opioid sparing effect of perioperative iv low-dose ketamine 4-8 and others have not. [9][10][11][12][13][14] These discrepancies may be due to the large interstudy variability in surgical procedures, patient population, dose of ketamine administered, timing of administration, and study design. 15,16 In studies that fail to demonstrate a preventive effect of a low-dose ketamine on postoperative pain, the question of whether a lack of efficacy on central sensitization is linked to insufficient pre-or postoperative blockade remains unresolved.…”