EPIDURAL KETAMINE REDUCES POSTOPERATIVE EPIDURAL PCA CONSUMPTION OF FENTANYL BUPIVACAINE/

Purpose: To study the analgesic effect of epidural ketamine on postope rative pain and epidural PCA consumption after total abdominal hystere ctomy. Methods: Sixty-one ASA I-II patients, 34-60 yr were randomly as signed into three groups. Epidural catheters were inserted before indu ction of anaesthesia, Patients in group I and II received 30 mg ketami ne epidurally before induction of anaesthesia or 20 min after skin inc ision: group III received placebo. Postoperatively, on first analgesia request, sedation score, Visual Analogue Scale (VAS), Prince Henry Sc ore (PHS) and Bromage motor weakness score were taken and followed by an epidural bolus of 9 mi bupivacaine 0.25% + 50 mu g Fentanyl. Analge sia was maintained by PCA with a mixture of bupivacaine 0.1% + fentany l 0.001% epidurally. Measurements were repeated at 1, 2, 4, 8, 12 and 24 hr. Results: First analgesia request was 17 +/- 6.8 min in the cont rol group compared with 31.4 +/- 23.8 and 44 +/- 23.1 min for groups I and II respectively. The differences between group III and group I (P < 0.05) and between group III and group II (P < 0.01) were statistica lly significant. Twenty four hour PCA consumption was 101.2 +/- 47.2, 87 +/- 27 and 162 +/- 38 mi for groups I, II and III respectively. The differences between group III and group I and that between group III and group II were statistically significant (P < 0.001). Conclusion: E pidural ketamine 30 mg reduces post hysterectomy pain as evidenced by prolongation of time to first analgesia request and reduction in posto perative epidural PCA consumption. This effect is manifest whether ket amine is given before induction or 20 min after skin incision.