Inflammation increases sufentanil requirements during surgery for inflammatory bowel diseases

Background and objective: Inflammation promotes hyperalgesia and increases opioid binding protein (α 1 -acid glycoprotein) inducing increased opioid requirement. To investigate the influence of an acute episode of inflammatory bowel disease in opioid requirement during major abdominal surgery, 17 patients with Crohn's disease, 12 patients with ulcerative colitis and seven patients without any inflammatory process (control group) were prospectively studied. Sufentanil requirements were assessed during surgery. Methods: Sufentanil administration was adjusted when haemodynamic variables changed more than 20% of preoperative values. In a subgroup of 20 patients (Crohn's disease: 7, ulcerative colitis: 7, control group: 6), plasma concentrations of α 1 -acid glycoprotein and unbound sufentanil were measured. Total plasma clearance of sufentanil was also determined. Data presented as median (25-75‰) were analysed by non-parametric and ANOVA tests. Results: Despite similar surgery duration, intraoperative sufentanil requirements were significantly larger in both the Crohn's disease group (0.9 (0.6-1.6) μg kg -1 h -1 ) and the ulcerative colitis group (1.1 (0.6-1.7) μg kg -1 h -1 ) than in the control group (0.5 (0.4-0.5) μg kg -1 h -1 ). Total plasma clearance of sufentanil was larger in patients with inflammatory bowel disease than in the control group. The plasma α 1 -acid glycoprotein concentration was increased in the inflammatory bowel disease group. However, the free fraction of sufentanil was similar in all three groups. The largest sufentanil consumption in patients with inflammatory bowel disease was observed during time of pain stimulation in the area of referred hyperalgesia from the affected viscus. In the control group, the sufentanil requirement was constant throughout surgery. Conclusion: Inflammatory bowel disease increases opioid requirement during major abdominal surgery.