Objective: To evaluate renal arterial resistance to flow by Doppler indices concurrently with ascites drainage in women with severe ovarian hyperstimulation syndrome.
Methods: We conducted an interventional clinical study of 19 women with severe ovarian hyperstimulation syndrome, manifested by free peritoneal fluid. The subjects were evaluated before and after therapeutic paracentesis by measuring urine output, blood urea nitrogen, intra-abdominal pressure, and renal artery flow measures by Doppler ultrasonography (systolic/diastolic ratio [S/D] and resistance index).
Results: An average of 3,340 mL of ascitic fluid was drained, and the intra-abdominal pressure decreased from 17.5 +/- 1.24 cm H2O to 10 +/- 1.22 cm H2O. Urine output was increased (by 65%, from 925 +/- 248 mL/d before paracentesis to 1,523 +/- 526 mL/d on the day after paracentesis, P <.001). The mean renal arterial S/D decreased from 3 +/- 0.15 to 2.29 +/- 0.13 (P =.001). Most of the decrease in intra-abdominal pressure as well as in renal vasculature resistance was apparent after an initial drainage of 2,000 mL. Additional fluid drainage had only negligible effect on intra-abdominal pressure and renal flow.
Conclusion: Paracentesis lowered intra-abdominal pressure and decreased renal arterial resistance (lowered S/D and resistance index), ultimately resulting in increased urine production. It is plausible that the beneficial effects of paracentesis on urine output in ovarian hyperstimulation syndrome are due to improved renal blood flow from a direct decompression effect.