Effect of pulmonary vascular pressure on lung lymph flow following seizures.

The effect of elevated baseline pulmonary vascular pressures on systemic and pulmonary vascular sequelae of prolonged seizures was studied in sheep. Five animals with seizures induced after baseline left atrial pressure elevations of 25 mm Hg were compared with animals treated with seizures alone. Seizure-induced elevations from baseline of systemic and pulmonary vascular pressures were identical in the two groups both in height and duration. In animals with left atrial balloon inflation prior to seizures, however, the peak pulmonary arterial and left atrial pressures were the sum of baseline elevation (induced by left atrial balloon inflation) and the seizure-induced pressure elevation. Accordingly, the resultant pulmonary vascular pressure and resultant pulmonary lymph flow elevations, were substantially greater in these animals with elevation in baseline pulmonary vascular pressures. Therefore, patients with pulmonary vascular hypertension are at greater risk for pulmonary edema during seizures.