A canine model of neurogenic pulmonary edema

The purpose of this study was to evaluate the usefulness of the intracisternal administration of veratrine as a model of neurogenic pulmonary edema (NPE) in the alpha-chloralose-anesthetized dog. Veratrine (40-60 micrograms/kg) was injected into the cisterna magna of 17 animals, and systemic arterial, pulmonary arterial, and left ventricular end-diastolic (LVEDP) pressures were followed for 1 h. Eleven animals developed alveolar edema. In these animals, systemic arterial pressure increased to 273 +/- 9 (SE) Torr, pulmonary arterial pressure to 74.5 +/- 4.9 Torr, and LVEDP to 42.8 +/- 4.5 Torr, and large amounts of pink frothy fluid, with protein concentrations ranging from 48 to 93% of plasma, appeared in the airways. Postmortem extravascular lung water content (Qwl/dQl) averaged 7.30 +/- 0.46 g H2O/g dry lung wt. Six animals escaped developing this massive degree of edema after veratrine (Qwl/dQl = 4.45 +/- 0.24). These animals exhibited similar elevated systemic arterial pressures (268 +/- 15 Torr), but did not develop the degree of pulmonary hypertension (pulmonary arterial pressure = 52.5 +/- 6.7 Torr, LVEDP = 24.8 +/- 4.0 Torr) observed in the other group. These results suggest that both hemodynamic and permeability mechanisms may play a role in the development of this form of edema and that veratrine administration may provide a useful model of NPE.