Lecture Summary

For patients under mechanical ventilation, the best precision medicine in 2022 is delivered based on respiratory physiology. One example is the use of driving pressure in patients with hypoxemic respiratory failure or acute respiratory distress syndrome (ARDS). Static pressure in the lung can be easily measured by the use of a short end-insufflation pause of 0.2 or 0.3 seconds, allowing to get the plateau pressure: this pressure represents the peak alveolar pressure and is an important indicator of the level of distension. In addition, the difference between this pressure and the end-expiratory pressure, or PEEP, is the elastic pressure for the system or the driving pressure. This driving pressure reflects the ratio of the tidal volume delivered to the compliance of the aerated lung available for ventilation. It is by far the strongest indicator of the risk of ventilation-induced lung injury, with excess mortality above 15 cmH2O. Interestingly it can also be measured during pressure support ventilation: in the latter case, however, the plateau pressure will be higher than the peak pressure because it contains the pressure related to the inspiratory effort of the patient.

Target Audience

Critical Care Doctors
Experienced or advanced Critical Care Nurses

Learning Objectives:

Upon completion of this activity, you should be able to:

• Describe the forces present during mechanical ventilation
• Understand how to estimate the risk of mechanical ventilation
• Know who to set the ventilator to assess these risks

Respiratory Physiology in Acute Respiratory Failure: 'Lung Recruitability'

a review

Critical Care Medicine / Mechanical Ventilation