Excessive fluid administration in resuscitating baboons from hemorrhagic shock, and an assessment of the thermodye technic for measuring extravascular lung water

The effects of fluid overloading in normal baboons and in baboons subjected to hemorrhagic shock are discussed in the first part of the present report. As expected, the overloaded animals developed pulmonary edema. They derived no benefit from overloading -in particular, their cardiac output did not significantly increase, and their clinical response to resuscitation did not improve with the overloading. Central venous pressures correlated well with wedge pressures, but both central pressures were labile, decreasing rapidly towards normal limits whenever fluid administration temporarily ceased. Thus, excessive reliance on intermittently measured central pressures in resuscitating patients from shock can lead to too much fluid. The second part of this report reviews our experience in twenty-nine baboons with the thermodye technic as a method for quantifying pulmonary edema in vivo. Under the conditions of these experiments, the thermodye technic accurately measured the gravimetrically determined postmortem extravascular lung water (EVLW) (r = 0.87, p < 0.001). Furthermore, in contrast to the double isotope indicator dilution technic, the amount of EVLW sensed by the thermodye technic did not depend on the type of pulmonary edema nor on the pulmonary blood flow.