The effect of surfactant therapy associated with high frequency jet ventilation on oxygenation in canine lavaged lungs

: The effects of exogenous surfactant (SF) replacement therapy associated with high frequency jet ventilation (HFJV) on blood gas changes, pulmonary and hemodynamic variables were studied in canine lavaged lungs. The lungs were lavaged repeatedly with physiological saline until PaO2 decreased to 100 mmHg under intravenous pentobarbital anesthesia with 100% oxygen. SF (50 mg.kg-1) in the experimental group (n = 12) and saline in the control group (n = 8) were administered to the trachea using HFJV with a duration of 10 min. HFJV was further continued for 1 hour to make surfactant distribute evenly. Then respiration was controlled by the conventional mechanical ventilator for 3 hrs. During the administration of SF (10 min). PaCO2 was not altered. In the surfactant group, PaO2 improved significantly (200 mmHg) at the end of HFJV and was maintained for the next 3 hrs at this level, but it did not improve in the saline group. Therefore, we suggest that HFJV can be used safely for the treatment of acute respiratory failure and is an effective method for the administration of the pulmonary surfactant into the alveoli.