Tension pneumothorax during one-lung ventilation: a case report.

A 76-year-old woman underwent double-lumen endotracheal tube intubation for right upper lobectomy. During one-lung ventilation, she developed tension pneumothorax on her dependent lung and suffered cardiac arrest. The presenting signs of tension pneumothorax--hypoxemia, hypotension, and increased airway pressure--are relatively common during this procedure, leading to a delay in diagnosis and effective treatment. When all three signs occur together during one-lung ventilation, cardiovascular collapse can result and serious consideration must be given to the diagnosis of tension pneumothorax in the dependent lung.