Is continuous infiltration of local anaesthetic/PCA an acceptable alternate pain management strategy in morbidly obese patients undergoing gastric bypass surgery? A retrospective comparison with epidural analgesia

Abstract

Background: Not like in general population, in obese siting the epidural catheter is a time consuming process and needs high level of nursing care during the postoperative period. In our institution we have done more than 1000 gastric bypasses over the last decade, most of them with postoperative epidural analgesia. Because of draw backs with epidural technique, recently we changed our practice to continuous infiltration/PCA technique. This is an attempt to see whether new technique is offering the same quality of analgesia to our gastric bypass patients during their postoperative stay. Methods: All the patients who had either epidural or PCA/continuous infiltration as their primary mode of analgesia, following gastric bypass surgery during the period of 1st June 2008 and 28th February 2009 were taken in to consideration. Pain was rated by the patient using VAS score at 0,2,6,12,24,36,48,72,96 hours and overall patient satisfaction at end of 96 hours. Side effects were also noted. Results: Out of 98 patients, only 87 patients (epidural 62, continuous infiltration / PCA 25) were considered in this study. Rest had either PCA alone (8 patients) or combination of epidural / PCA (intentionally - 1,convertion of epidural to PCA - 2). Epidural group consisted of 21 (33.9%) males, 41 (66.1) females, age 48.2+/-10.4 (23-69 years), BMI 48.9+/-9.66 (34-86) and PCA/infiltration group 3 (12%) males, 22 (88%) females, age 47.36 + /- 12.08 (19-71) BMI 46.6 + /-7. 65 (36-65). Continuous infiltration / PCA provided same degree of pain relief as epidural infusion. Except for nausea and vomiting (60%), other side effects were less with continuous infiltration/PCA (pruritus, urinary retention, wound infection). 11.3% of epidurals group developed hypotension and 36% of infiltration / PCA group mentioned oozing as a side effect. In epidural group 13% rated it as excellent, 37% as very good, 50% as good while in infiltration/PCA group 36% related as excellent, 48% as very good and 16% as good. Conclusion: Continuous infiltration/PCA technique provides equally effective postoperative analgesia after gastric bypass surgery, compared to epidural infusion, with comparatively less side effects and more patient satisfaction.