The bedside determination of extravascular lung water: a non-invasive double indicator technique using 123I-antipyrine, 113mIn-transferrin and external counting.

Using the formulae of Fazio and coworkers, we calculated the extravascular lung water per unit of blood volume (ELW/V) and per unit of blood flow (ELW/F) after intravenous injection of 113In-transferrin as the blood label, and 123I-antipyrine as the diffusible, i.e. water label. Time-activity curves were recorded over the right anterior upper chest wall using a mobile detector. The curves were digitalized and fitted to a gamma-variate using a GAMMA-11 computer. Area over height calculations gave the mean transit times (t). Sixteen control subjects, without evidence of cardiac or pulmonary disease, and 10 patients, with clinical and radiological evidence of left heart failure, were examined. In the control group ELW/V was 0.37 plus or minus 0.17 and ELW/F 3.39 plus or minus 1.56 (mean plus or minus 1 SD). In the patients ELW/V was 0.71 plus or minus 0.26 and ELW/F 13.10 plus or minus 5.67. The difference between both ELW/V and ELW/F for the control group and the patient group is statistically significant. Our values for ELW/V both in patients and control subjects are very similar to those obtained by Fazio and coworkers using H2 15O. However, our values for ELW/F differed from those of Fazio; this could be partly due to dependence of this parameter on the cardiac output.