The intraabdominal pressure in decompensated cirrhosis: relationship with ascites volume and turn-over.

The values of the intraabdominal pressure (IAP) were determined in 23 subjects with decompensated cirrhosis, both in basal conditions and after diuretic treatment (furosemide 75 mg/day orally for one week). In order to investigate the role of IAP in the regulation of ascites turn-over, ascites volume and free-water peritoneal clearance (FWPC) were estimated in the same patients by means of a methylene-blue dilution method. In wash-out conditions, no linear correlation was found between IAP and the values of ascites volume or FWPC. After diuretic treatment, we observed a significant reduction of ascites volumes (from 9.0 +/- 0.98 to 4.9 +/- 0.6 litres; p < 0.0005), IAP (from 17.5 +/- 1.3 to 11.3 +/- 0.8 cmH2O; p < 0.0005) and FWPC (from 99.8 +/- 6.7 to 76.2 +/- 6.6 ml/min; p < 0.001). In this situation, IAP values showed a significant linear correlation both with ascites volumes and clearances. These results may be due to the different weight of the two components of total IAP (hydrostatic pressure and abdominal tension): in the untreated patients (with larger ascites volumes) a considerable amount of the total IAP originates from the abdominal tension, and the correlation between IAP and ascites volumes or turn-over is biased. In the treated subjects (with lower ascites volumes) the tension component is minimal, and the correlation is resumed.