抄録
In five unanesthetized sheep in which chronic lung lymph fistulas were made, we infused air emboli (ca 300μm in diameter) into the pulmonary trunk, resulting in an increase in pulmonary arterial pressure (Ppa) and lung lymph flow (Qlym). Bolus air infusion of 0.5ml/kg increased Ppa to 40.0±1.0cmH2O from the average base line value of 26.0±1.1cmH2O in 14 successful embolizations and the elevated Ppa level was maintained for 15 minutes, 1 and 3 hours following air emboli infusion, at a rate of 0.06ml/kg/min. After starting air infusion, Ppa returned rapidly to base line levels.
Qlym began to increase following Ppa elevation and reached a peak flow one hour following embolization for 15 minutes and for one hour embolization, therafter decreasing gradually. In the three hour air embolization experiments, Qlym increased progressively, reaching a new steady state within the second hour. The average in-creases in Qlym following 15 minutes, 1 and 3 hour-embolizations were 61.5%, 151% and 476% of their base line, respectively. The increases in Qlym were proportional to the durations of air embolization at a constant Ppa level of 40cmH2O.
In the steady state of the last 2 hours of 3 hours emboli experiments, the protein concentration ratio of lymph/plasma and did not change significantly, resulting in a 211% average increase of calculated fluid permeability coefficient (Kf) from the average base line value of 2.1ml/cmH2O/hr/100g lung in 4 successful experiments.
The effects of air embolization on Ppa and Qlym were completely reversible. We produced reversible permeability pulmonary edema in awake standing sheep.
