Colloid osmotic pressures,plasma volume and interstitial fluid volume in patients with heart failure

Fauchald P. Colloid osmotic pressures, plasma volume and interstitial fluid volume in patients with heart failure. Scand J Clin Lab Invest 1985; 45: 701–706.

In 13 patients with heart failure colloid osmotic pressure in plasma (II_p) and in subcutaneous interstitial fluid from thorax (II_i) (wick technique), plasma volume (PV) and interstitial fluid volume (IFV) were measured and correlated to haemodynamic parameters (cardiac index (CI) and right atrial pressure (RAP)). In seven patients with anasarca measurements of II_P, II_i, PV and IFV were repeated after fluid withdrawal (mean 7786 ml) by ultrafiltration. In the patients, IIj was reduced compared with normal subjects (11.5±3.4 versus 15.8±2.7 mmHg, p<0.01 (mean±SD)) and transcapillary colloid osmotic gradient (II_p - II_i) increased (14.6±2.3 versus 12.8±2.7 mmHg, p<0.05). The IFV in the patients was increased to 137% of values in normal subjects (p<0.01) and the ratio PV/IFV significantly reduced. Correlations were found between II_i and CI(r=0.69, p<0.01) and II; and RAP (r=0.78, p<0.01). Ultrafiltration led to a parallel decrease in PV and IFV and increase in II_p. The results indicate that reduced II_i is an important factor limiting peripheral oedema in heart failure and the reduction is more pronounced in severe heart failure. The reduction of II_i is due to both dilution of interstitial proteins and to reduction of interstitial protein mass by lymphatic wash-out.