HFV (High Frequency Ventilation)

Abstract

Since 1982, we have used HFJV as one of the routine ventilatory modes. The purposes of it's application are (1) improvement of oxygenation, (2) lowering of the maximum inspiratory pressure and (3) physiotherapy.
We examined HFJV for these 3 criteria and the results are as follows.
1. HFJV improves oxygenation, PaO₂ elavats, A-a DO₂ decreases and respiratory index also decreases. Using mongreal dogs, we made pulmonary edema model by administration of 0.07-0.1ml/kg oleic acid via S-G catheter. Then we compared HFJV and CMV under the condition of same mean airway pressure. Almost all parameters, such as PaO₂, A-a DO₂, respiratory index and cardiac index were nearly same under this condition. We concluded only PEEP effect of HFJV results in improvement of oxygenation.
2. Lowering of the maximum inspiratory pressure is effective for prevention and treatment of barotrauma.
3. HFJV for physiotherapy is most effective. It's useful treatment method to not only usual atelectasis but also intractible status asthmatics. Soon after application of HFJV to these patients, we could suction large amounts of secretions and then they improved clinically.
Especially HFJV was effective to the intractible status asthmaticus patients, who don't respond existing vigorous treatments such as administration of large amounts of fluid, xantines, steroids, epinephrine and isoproterenol, conventional mechanical ventilation and inhalation anesthesia. We think HFJV solves mucous plug by internal vibration and for that reason it is effective to the intractible status asthmatics.