Rapid identification of spontaneously resolving capnothorax using bedside M-mode ultrasonography during laparoscopic surgery: the "lung point" sign -two cases report-
A 39-year-old man, 165 cm, 63 kg, was scheduled for living right donor nephrectomy via hand-assisted laparoscopic surgery (HALS). The patient was normal on preoperative evaluation and presented without a specific medical history. The induction of anesthesia with thiopental sodium, fentanyl, vecuronium and desflurane was uneventful. The patient was placed in the left lateral decubitus position. After CO2-pneumoperitoneum was induced, the intraabdominal pressure was maintained < 14 mmHg, and ETCO2, Pmax, and SpO2 were 33 mmHg, 23 cmH2O and 100%, respectively. When the upper pole of the kidney was approached, the diaphragm was injured by the dissector, which was immediately repaired. The surgeon inquired about the status of the right lung because the right hemidiaphragm was bulging. The lung sounds in the right chest were decreased on auscultation, and ETCO2 and Pmax were increased to 42 mmHg and 30 cmH2O, respectively. However, SpO2 was maintained at 100%. At that point, we evaluated the right thorax using ultrasonography (linear probe: L25x, 6-12 MHz, machine: M-turbo System®, Sonosite Inc., Bothell, WA, USA) in the operative field, and the "lung point" sign was found at the right lower anterior axillary line (). Considering the location of the lung point sign, a small amount of pneumothorax was expected. However, because the hemodynamic parameters were maintained in a normal range, the operation was continued via HALS and a PEEP of 5 cmH2O was applied.\nAt the end of the surgery, the surgeon requested a portable chest radiography and we concurrently examined the patient using ultrasonography in the supine position. Chest radiography indicated a pneumothorax < 20% (), and the range of the pneumothorax which was indicated by the lung point sign was gradually diminished. Because signs of cardiopulmonary instability were not found and SpO2 was maintained without an increase in FiO2, the insertion of a chest tube was not necessary and we safely extubated the endotracheal tube. The patient was transferred to the PACU and did not complain of any respiratory discomfort.