[Pulmonary oedema ex vacuo (author's transl)].

Area of Science:

• Pulmonary Medicine
• Critical Care Medicine

Background:

• Upper airway obstruction (UAO) in spontaneously breathing patients can lead to significant negative intra-alveolar pressure.
• Pulmonary edema ex vacuo is a recognized complication of severe UAO.

Observation:

• Four cases of spontaneously breathing patients with UAO lasting hours, resulting in pulmonary edema, are presented.
• One case of pulmonary edema following lung re-expansion in a ventilated patient is also described.

Findings:

• Negative intra-alveolar pressure during UAO alters physiological parameters, contributing to pulmonary edema ex vacuo.
• Pulmonary edema post-re-expansion, unlike edema ex vacuo, was not linked to negative intra-alveolar pressure due to positive pressure ventilation.
• Capillary damage from hypoperfusion, altered alveolar lining layer, and infection are implicated in re-expansion pulmonary edema.

Implications:

• Understanding the distinct mechanisms of different pulmonary edema types is crucial for appropriate diagnosis and management.
• Recognizing pulmonary edema ex vacuo in UAO patients guides therapeutic strategies.
• Further research into the pathophysiology of re-expansion pulmonary edema may improve patient outcomes.