Setting PEEP using transpulmonary pressure measurement

The ability to partition between the lung and chest wall components helps you to set the optimal PEEP, define a safe range for driving and plateau pressures, and to titrate and optimize lung recruitment maneuvers. But how can you distinguish between them when the pressures measured at the airway opening cannot be used to accurately assess the stress and strain applied to the lungs? A simple way of partitioning them is by using esophageal pressure measurement. The airway pressure minus the esophageal pressure measured during an end-inspiratory or an end-expiratory occlusion gives you the transpulmonary pressure, which represents the true distending pressure of the lungs.

Transpulmonary pressure measurement is available on the HAMILTON-G5/S1 (Not available in the US and some other marketsA​) and HAMILTON-C6 ventilators, which are equipped with an auxiliary port for the connection of an esophageal catheter. This is inserted through a nostril to the stomach and then withdrawn into the esophagus, with the balloon being positioned in the lower third of the esophagus. On the ventilator display, simply change to the four-waveform setting and the lower two waveforms will then show you the esophageal and transpulmonary pressure. You can freeze the screen to read the values.

In patients with acute respiratory distress syndrome (ARDS), you can set PEEP in order to achieve a transpulmonary pressure of 0 to 5 cmH2O at end expiration, with the aim of preventing atelectrauma caused by repeated opening and closing of the distal airways and alveoli. Transpulmonary pressure measurement can also be used to set the tidal volume, and inspiratory pressure for ARDS patients, and together with the P/V Tool® to assess lung recruitability and perform recruitment maneuvers. 

This video below shows you how to set PEEP using transpulmonary pressure measurement on a HAMILTON-G5 ventilator.