Fig. 3
Examples of inspiratory and expiratory static esophageal balloon pressure-volumes curves. Circles refer to end-expiratory esophageal pressure (PesEE); closed circles refer to VMIN and VMAX as graphically detected (respectively lower and upper limits of the intermediate linear section of the curve). Squares refer to end-inspiratory esophageal pressure (PesEI); closed squares refer to VBEST (the filling volume associated with the largest PesEI – PesEE difference). Panel (a) 32-year-old male patient, body mass index (BMI) 27 kg/m2; pulmonary alveolar proteinosis and kyphoscoliosis; positive end-expiratory pressure (PEEP) 0 cmH20; tidal volume (TV) 550 ml, plateau pressure (Pplat) 20 cmH2O. VMIN and VBEST 0.5 ml. Esophageal elastance 1.3 cmH2O/ml, pressure generated by the esophageal wall (Pew) at VBEST 0.0 cmH2O. Panel (b) 82-year-old female patient, BMI 22 kg/m2; respiratory failure after pulmonary endoarterectomy; PEEP 7 cmH20, TV 500 ml, Pplat 25 cmH2O. VMIN 0.5 ml and VBEST 3 ml. Esophageal elastance 1.3 cmH2O/ml, Pew at VBEST 3.3 cmH2O. Panel (c) 31-year-old male patient, BMI 63 kg/m2; legionella pneumonia and morbid obesity; PEEP 12 cmH20, TV 450 ml, Pplat 30 cmH2O. VMIN 2.5 ml and VBEST 4.0 ml. Esophageal elastance 1.2 cmH2O/ml, Pew at VBEST 1.8 cmH2O. Panel (d) 70-year-old male patient, BMI 23 kg/m2; intra-abdominal hypertension due to large retroperitoneal hematoma; PEEP 10 cmH20, TV 370 ml, Pplat 29 cmH2O. VMIN 1.5 ml and VBEST 6 ml. Esophageal elastance 0.8 cmH2O/ml, Pew at VBEST 3.6 cmH2O. Pes esophageal pressure