Changes in Plasma Levels of Vasoactive Factors in Patients Undergoing Abdominal Surgery

Abstract

Background: To investigate the changes in plasma levels of endothelin (ET), nitric oxide (NO), prostacyclin (PGI 2 ) and thromboxane A 2 (TXA 2 ) in patients undergoing abdominal operation. Materials and Methods: Thirty cases of abdominal surgery (14 males, 16 females; mean age 48 ± 11 years, ranging from 24 to 70) were prospectively recruited: Twenty-four cases of cholelithiasis and cholecystitis, 2 cases of peptic ulcer and 4 cases of portal vein hypertension. At five different time points (1-3 days after hospitalization (T1), at surgery beginning, after anesthesia (T2) and at the first (T3), third (T4) and fifth day (T5) after surgery), plasma levels of ET-1, NO 2 - , NO 3 - , 6-keto-PGF 1 α and thromboxane B 2 (TXB 2 ), the latter two being stable metabolites of PGI 2 and TXA 2 respectively, were measured. Results: ET-1 levels increased significantly after anesthesia and surgery (T1 = 69.2 ± 10.7 vs. T2 = 82.4 ± 14.7 vs. T3 = 96.6 ± 22.8 pg/ml, p < 0.05). TXB 2 levels before surgery were significantly lower than that after (T2 = 67.5 ± 52.7 vs. T3 = 157.6 ± 21.8 pg/ml, p < 0.05). Pre-surgery NO levels were significantly higher than that after surgery (T1 = 2575 ± 50 vs. T2 = 1922 ± 44 vs. T3 = 1692 ± 39 ng/ml, p < 0.05 for T1 vs. T2 and T3). Pre-surgery levels of 6-keto-PGI 1 α were significantly higher than that after anesthesia and surgery (T1 = 180.5 ± 17.8 vs. T2 = 132.1 ± 32.6 vs. T3 = 110.9 ± 31.9 pg/ml, p < 0.05 for T1 vs. T2 and T3). Conclusions: Level of vasoconstrictive factors (ET and TXA 2 ) increased significantly after surgery, while vasodilatory factors (NO and PGI 2 ) decreased significantly after operation. Imbalance in vasoactive factors encourages hypercoagulability and then may play a role in the pathobiology of post-surgery complications, such as deep venous thrombosis (DVT).