SALALATE, MORPHINE, AND POSTOPERATIVE ILEUS

BACKGROUND: Previously, we demonstrated that ketorolac,a nonsteroidal antiinflammatory drug (NSAID), prevented postoperative Small bowel lle us in a rodent model, The aim of this study was to evaluate the effect of salsalate, an NSAID without antiplatelet effect, on postoperative ileus alone or in combination with morphine. METHODS: Forty-eight rats underwent placement of duodenal catheters and were then randomly assi gned to one of eight groups (n = 6), Four groups had standardized lapa rotomy following drug administration, whereas 4 groups underwent the s ame treatment without laparotomy: control and morphine animals receive d 0.1 mi alcohol via the catheter, whereas salsalate and salsalate-plu s-morphine animals received salsalate (15 mg/kg) dissolved in 0.1 mt a lcohol, The animals also received 0.5 mg/kg morphine (morphine and sal salate plus morphine) or the same volume of saline (control and salsal ate) subcutaneously, Transit was measured following the injection bf a nonabsorbed marker via the duodenal catheter and is defined as the ge ometric center (GC) of distribution, An additional 20 rats had serosal electrodes placed on the jejunum, and were assigned to one of four tr eatment groups (control, salsalate, morphine, and salsalate plus morph ine; n = 5 each group), Myoelectric activity was recorded until the re appearance Of the migrating myoelectric complex (MMC) following laparo tomy. RESULTS: Laparotomy and morphine independently reduced small bow el transit (P = 0.0006 and 0.006, respectively, by three-way analysis of variance [ANOVA]; GC 4.3 +/- 0.2 control versus 2.2 +/- 0.3 laparot omy versus 3.6 +/- 0.4 morphine), but morphine did not further worsen postoperative transit (GC 2.4 +/- 0.4; P = 0.42). Although salsalate d id not alter baseline transit, pretreatment improved postoperative tra nsit (P = 0.0002; GC 3.6 +/- 0.4), This effect was lost with the addit ion of morphine (GC 2.7 +/- 0.2; P = 0.21), The MMCs returned earlier after laparotomy in salsalate-pretreated rats (63 +/- 18 minutes salsa late versus 160 +/- 12 minutes laparotomy; P <0.01, one-way ANOVA), Ho wever, this effect was also lost in animals receiving morphine (106 +/ - 16 min; P >0.05). CONCLUSION: Salsalate improves postoperative small bowel motility in a rodent model; however, this effect is masked by m orphine.