Q: 46 year old male is in ICU intubated secondary to pneumonia and ARDS, requiring high "Bilevel" settings. Suddenly ventilator starts having high peak pressure alarm. What should be your next step?

Answer:

In event of sudden high peak pressure, hemodynamics are the first priority. If patient's hemodynamics are unstable, patient should be removed from the ventilator and bagged manually, and cause should be identified particularly auto-PEEP or tension pneumothorax - in patients with high PEEP settings. If hemodynamic improves with bagging auto-PEEP may be the likely cause. If it does not improve, tension pneumothorax should be high on list.

If patient's hemodynamics allow, a plateau pressure (Pplat) should be determined. In stable patient plateau pressure can be determined by getting an inspiratory pause on the ventilator.

If the difference between Ppeak and Pplat  is higher than about 5 cm/H20, probable causes are related to elevated airway resistance as bronchospasm, endotracheal tube obstruction or ventilator circuit obstruction.

If the difference between Ppeak and Pplat  is lower than about 5 cm/H20 cause is likely secondary to acute decrease of lung compliance as pneumothorax, pulmonary edema,  worsening ARDS, and auto-PEEP.