The pathophysiology of ovarian hyperstimulation syndrome: an unrecognized compartment syndrome

Objective: To compare and contrast the pathophysiology of ovarian hyperstimualtion syndrome (OHSS) with known syndromes of increased intraabdominal pressure (IAP), and to explore the relationship of increased IAP with symptom severity in OHSS. Design: Literature review. Main Outcome Measure(s): Correlation of OHSS symptoms with IAP; effects of paracentesis on IAP in patients with OHSS. Setting: Academic Research Institution. Intervention(s): None. Result(s): OHSS involves a rapid accumulation of volume (from 1.5-17 liters) in the peritoneal cavity that can lead to organ dysfunction, including respiratory impairment and oliguria. In published reports of 20 moderate-to-severe OHSS patients in whom IAP was measured, IAP was found to be elevated to a pathologic range. The increased IAP indicates that OHSS may be considered a compartment syndrome and meets criteria for abdominal compartment syndrome in advanced cases. For this reason, management of OHSS should include reduction of pressure by paracentesis to avoid morbidity and syndrome progression. In addition, measurement of IAP may help to classify the stage of OHSS. Conclusion(s): IAP was found to be elevated in the few cases of OHSS in which it was measured, substantiating the conclusion that OHSS may be considered a compartment syndrome. An understanding of the pathophysiology of increased intrabdominal pressure is useful in the management of OHSS. (Fertil Steril (R) 2010;94:1392-8. (C) 2010 by American Society for Reproductive Medicine.)