INCREASED INTRAABDOMINAL PRESSURE AND CARDIAC FILLING PRESSURES IN OBESITY-ASSOCIATED PSEUDOTUMOR CEREBRI

Objectives. To determine whether intra-abdominal pressure (as estimate d from urinary bladder pressure) is elevated in patients with central obesity (as measured by sagittal abdominal diameter) and pseudotumor c erebri and whether this increased intra-abdominal pressure is associat ed with increased pleural pressure and cardiac filling pressure, imply ing a resistance to venous return from the brain. Design. Nonrandomize d, prospective. Setting. University hospital, operating room. Main out come measurements. Intracranial pressure, urinary bladder pressure, sa gittal abdominal diameter, transesophageal pleural pressure, central v enous pressure, pulmonary artery pressure, and pulmonary artery occlus ion pressure. Subjects. Six women with pseudotumor cerebri (one with C SF leak, one with lumboperitoneal shunt). Results. Urinary bladder pre ssure (22 +/- 3 cm H2O) and sagittal abdominal diameter (29 +/- 3 cm) were significantly elevated in these patients with elevated intracrani al pressure (293 +/- 80 mm H2O) compared with a previously reported gr oup of nonobese control patients. The transesophageal pleural pressure (15 +/- 10 mm Hg), central venous pressure (20 +/- 6 mm Hg), mean pul monary artery pressure (31 +/- 6 mm Hg), and pulmonary artery occlusio n pressure (21 +/- 7 mm Hg) were all markedly elevated compared with p ublished normal values and with previous data from obese patients with out pseudotumor cerebri. Conclusions. These data support the hypothesi s that central obesity raises intra-abdominal pressure, which increase s pleural pressure and cardiac filling pressure, which impede venous r eturn from the brain, leading to increased intracranial venous pressur e and increased intracranial pressure associated with pseudotumor cere bri.