A 28 year old woman developed severe breathing difficulty after delivering her first baby normally. Xray chest showed bilateral fluffy infiltrates in the lungs. Her PaO2 was 60 mmHg and PaCO2 was 60 mmHg. It was decided to put her on mechanical ventilation. The mode which is appropriate include all except.
  1. Synchronous intermittent mandatory ventilation
  2. Inverse ratio ventilation
  3. Positive End Expiratory Pressure
  4. Permissive hypercapnia

Answer : The answer is (a). Inverse ratio ventilation uses high inspiration:expiration ratio to stabilize terminal respiratory units to improve gas exchange in patients with Acute Respiratory Distress syndrome. Permissive hypercapnia is a method whereby controlled hypoventilation (control only on not allowing severe hypopnea) is allowed to reduce the pressure effects on the small airways. Positive End Expiratory Pressure helps to keep the terminal airways open during end of respiration.