[Clinical evaluation of high-frequency positive pressure ventilation (HFPPV) in morbid obesity]

Clinical evaluation of High Frequency Positive Pressure Ventilation (H.F.P.P.V.) was made in 12 morbid obese patients undergoing elective gastric bypass or gastric partition operation. A conventional respirator of the Air-Shields type was used working at a frequency varying between 60-90 min and I.E. ratio 1:3. After induction of anesthesia serial measurements of arterial blood gases were performed during conventional Intermittent Positive Pressure Ventilation (I.P.P.V.) and H.F.P.P.V. the patient being his own control. No significant differences between the two methods of ventilation were found with respect to arterial systemic blood pressure, arterial oxygen and carbon dioxide tensions. The relatively low intra-tracheal pressures during H.F.P.P.V. were adequate to produce efficient oxygenation and ventilation with optimal conditions for the surgical intervention.