Mechanisms of early decrease in systemic vascular resistance after total paracentesis:: influence of flow rate of ascites extraction

Background An early decrease in systemic vascular resistance (SVR) after total paracentesis has been observed in ascitic patients who developed paracentesis-induced circulatory dysfunction. Aims To investigate the mechanisms of early changes in SVR after total paracentesis and the influence of intra-abdominal pressure and the flow rate of ascites extraction on the development of an early decrease in SVR. Methods Twenty-two cirrhotic patients with tense ascites were treated by total paracentesis (7 +/- 0.41). Measurements of intra-abdominal pressure and the volume of ascites removed were recorded every 10 min. Hormonal and haemodynamic measurements were performed at baseline and 3 h after total paracentesis. Results SVR decreased 3 h after paracentesis in 17 patients and remained stable in five patients. Patients with a decrease in SVR showed a significant increase in nitrite/nitrate serum values (4.4 +/- 0.9 to 7.4 +/- 1 nmol/ml; P < 0.05). A significant correlation was observed between the decrease in SVR and nitrite/nitrate serum values (r = 0.566; P < 0.05). The volume of ascites removed was similar in patients with and without a decrease in SVR. Patients with a decrease in SVR showed higher baseline intra-abdominal pressure, shorter duration of paracentesis (60 +/- 4.9 vs 88 +/- 0.4 min; P < 0.01) and higher flow rate of ascites extraction (1.18 +/- 0.08 vs 0.81 +/- 0.12 l/min; P < 0.05). Conclusions Our results confirm that an early decrease in SVR after total paracentesis is due to an increase in arterial vasodilation that may be related to an abrupt decrease in intra-abdominal pressure after fast paracentesis. Haemodynamic disturbances after total paracentesis could be prevented by reducing the flow rate of ascites extraction. (C) 2004 Lippincott Williams Wilkins.