Physiological effects of an open lung ventilatory strategy titrated on elastance-derived end-inspiratory transpulmonary pressure: study in a pig model*

Crit Care Med. 2012 Jul;40(7):2124-31. doi: 10.1097/CCM.0b013e31824e1b65.


Rationale: In the presence of increased chest wall elastance, the airway pressure does not reflect the lung-distending (transpulmonary) pressure.

Objective: To compare the physiological effects of a conventional open lung approach titrated for an end-inspiratory airway opening plateau pressure (30 cm H2O) with a transpulmonary open lung approach titrated for a elastance-derived end-inspiratory plateau transpulmonary pressure (26 cm H2O), in a pig model of acute respiratory distress syndrome (HCl inhalation) and reversible chest wall mechanical impairment (chest wall and abdomen restriction).

Methods: In eight pigs, physiological parameters and computed tomography were recorded under three conditions: 1) conventional open lung approach, normal chest wall; 2) conventional open lung approach, stiff chest wall; and 3) transpulmonary open lung approach, stiff chest wall.

Measurements and main results: As compared with the normal chest wall condition, at end-expiration non aerated lung tissue weight was increased by 116 ± 68 % during the conventional open lung approach and by 28 ± 41 % during the transpulmonary open lung approach (p < .01), whereas cardiac output was decreased by 27 ± 19 % and 22 ± 14 %, respectively (p = not significant).

Conclusion: In this model, the end-inspiratory transpulmonary open lung approach minimized the impact of chest wall stiffening on alveolar recruitment without causing hemodynamic impairment.

MeSH terms

  • Acute Lung Injury / therapy
  • Animals
  • Blood Volume
  • Carbon Dioxide / blood
  • Cardiac Output
  • Continuous Positive Airway Pressure
  • Disease Models, Animal
  • Lung Volume Measurements
  • Oxygen / blood
  • Positive-Pressure Respiration / methods*
  • Radiography, Thoracic
  • Stroke Volume
  • Swine
  • Tomography, X-Ray Computed


  • Carbon Dioxide
  • Oxygen