Interstitial fluid volume, plasma volume and transcapillary colloid osmotic gradient in patients with hepatic cirrhosis and fluid retention

Abstract

Colloid osmotic pressure in plasma (II_p) and in subcutaneous interstitial fluid (II_i) (wick technique), plasma volume (PV) and interstitial fluid volume (IFV) were measured in 12 patients with hepatic cirrhosis and fluid retention. The value of II_p (mean±SD) was 21.4±4.2 mmHg (28.6±3.4 mmHg in normal subjects (p<0.01)), mean II_i was 8.6±2.2 mmHg (15.8±2.7 mmHg in normal subjects (p<0.01)) and mean transcapillary colloid osmotic gradient (II_p-II_i) was 12.7±3.8 mmHg compared to 12.8±2.7 mmHg in normal subjects (p<0.1). Mean PV was increased by 21% compared to normal values (p<0.01) and IFV increased by 43% (p<0.01). The study demonstrates that reduction in II_p in hepatic cirrhosis is accompanied by a decrease of II_i in subcutaneous tissue resulting in unchanged transcapillary colloid osmotic gradient. The reduction in II_i can partly be explained by simple dilution and partly by a decrease in interstitial protein mass. The wash-down of interstitial proteins in non-splanchnic tissues reduces the tendency to oedema and hypovolaemia.

Key Words:

• colloid osmotic pressure
• hepatic cirrhosis
• interstitial fluid volume plasma volume