Diaphragm Thickening Fraction as a Prognostic Imaging Marker for Postoperative Pulmonary Complications in Robot-Assisted Laparoscopic Prostatectomy Requiring the Trendelenburg Position and Pneumoperitoneum

Table 1

Diagnostic criteria for postoperative pulmonary complications in robot-assisted laparoscopic prostatectomy.

Complication	Definition
Atelectasis	Atelectasis was defined as lung opacification with a shift of the hilum, hemidiaphragm, or mediastinum toward the affected side and compensatory overinflation in the adjacent nonatelectatic lung.
Pleural effusion	Pleural effusion was defined as chest X-ray showing loss of the sharp silhouette of the ipsilateral hemidiaphragm in the upright position, evidence of displacement of adjacent anatomical structures, blunting of the costophrenic angle, or a hazy opacity in one hemithorax with preserved vascular shadows.
Bronchospasm	Bronchospasm was defined as newly developed expiratory wheezing that needed treatment with bronchodilators.
Pneumothorax	Pneumothorax was defined as air in the pleural space without vascular bed surrounding the visceral pleura.
Respiratory infection	Respiratory infection was diagnosed as the need of treatment with antibiotics for suspected respiratory infection and as the occurrence of one or more of the following symptoms: new or changed sputum, fever, new or changed lung opacities, or leukocyte count more than 12,000/mm^3.
Aspiration pneumonitis	Aspiration pneumonitis was defined as an acute lung injury due to aspiration of gastric contents.
Respiratory failure	Respiratory failure was defined as a partial arterial oxygen pressure/fractional inspired , in room air, or arterial oxygen saturation measured with and requiring oxygen therapy.

Atelectasis, pleural effusion, and pneumothorax were diagnosed with radiologist’s description of chest X-rays.