Tension pneumothorax manifested after extubation in a patient who underwent total gastrectomy

A patient developed tension pneumothorax immediately after extubation. The patient was a 53-year-old man, who underwent total gastrectomy under general anesthesia combined with epidural anesthesia. The posterior mediastinum drainage tube was placed near the site of esophago-jejunum anastomosis. Surgeons reported that they might have injured left diaphragmatic pleura during the procedure. Postoperative chest X-ray showed no abnormal findings in the both lung fields. Patient's trachea was extubated when he emerged from anesthesia. However, Spo2 rapidly dropped from 100 to 88. Re-intubation was performed, and positive pressure ventilation was resumed. The Spo2 returned quickly to 100 without hemodynamic change. Auscultation revealed reduced respiratory sound from the left lung. Diagnosis of tension pneumothorax was made from emergency chest X-ray. Patient's respiration improved when chest tube was inserted, but a large amount of air was continuously drained. Air leakage decreased significantly when the mediastinum drainage tube was tentatively occluded. The possible mechanism of the positive pressure in the thoracic cavity was assumed that air was introduced with spontaneous inspiration from the drainage tube, and damaged pleura played as a check valve.