Managing Hypercapnia in Patients with Severe ARDS and Low Respiratory System Compliance: The Role of Esophageal Pressure Monitoring—A Case Cohort Study

Figure 3

Relationship between EITP and PaCO₂. Patients 1 to 4 had a low EITP which resulted in extremely low tidal volumes. The increase in inspiratory driving pressure increased EITP with resulting increase in tidal volumes and eventual decrease in PaCO₂. However, patients 5 and 6 had a high EITP due to inappropriately high PEEP pressure reflected by the high EETP. Consequently, PEEP was lowered to obtain a close to zero EETP. The resulting decrease in EETP resulted also in a decrease in EITP, both of which resulted in a significant decrease in PaCO₂ from 140 to 96 and from 81 to 50 mmHg in patients 5 and 6, respectively. EITP: end inspiratory transpulmonary pressure, EETP: end expiratory transpulmonary pressure, and PEEP: positive end expiratory pressure.