Effect of profound normovolemic hypotension and moderate hypothermia on circulating cytokines and adhesion molecules

Hypotension caused by hypovolemic, hemorrhagic shock induces disturbances i n the immune system that may contribute to an increased susceptibility to s epsis. The effect of chemically induced hypotension on circulating cytokine s and adhesion molecules has not been investigated yet. In 21 patients sche duled for resection of malignant choroidal melanoma of the eye the perioper ative serum levels of the cytokines IL-1 beta, IL-6, IL-10, TNF-alpha, and the adhesion molecules sE-Selectin and sICAM-1 were investigated. Moderate hypothermia of 32 degrees C was induced in all patients. In 14 patients pro found hypotension (mean arterial blood pressure 35-40 mmHg, hypotension gro up) was induced by enalapril and nitroglycerin for a mean duration of 71 mi n. In 7 patients the tumor was not resectable, and hypotension was not indu ced (controls), We did not detect significant differences in serum levels o f cytokines or sE-Selectin perioperatively in patients with profound hypote nsion compared with controls. In both groups IL-6 serum levels increased si gnificantly and reached a maximum after rewarming (17 +/- 6 and 16 +/- 5 pg /dL, respectively, P < 0.001). IL-1 beta, IL-10, and TNF-alpha did not chan ge perioperatively in both groups. On the first postoperative day sICAM-1 s erum levels were significantly increased in both groups (mean increase of 9 6 and 54 ng/mL, respectively, P < 0.01 and P < 0.05). We conclude from this study that profound normovolemic arterial hypotension does not seem to hav e effects on serum levels of circulating IL-1 beta, IL-6, IL-10, TNF-alpha, and sE-Selectin. Perioperative moderate hypothermia may be the reason for the postoperative increase in sICAM-1 levels independent of the blood press ure.