title: Prediction of postoperative dyspnea and chronic respiratory failure.
abstract: BACKGROUND
  Even among patients considered to be functionally eligible for major lung resection, some experience postoperative dyspnea. Based on our previous study with quantitative computed tomography (CT), we hypothesized that postoperative dyspnea is associated with the collapse of the remaining lung, and thus, prediction of the postoperative lung volume may contribute to risk assessment for postoperative dyspnea.
  
  
  METHODS
  We measured the emphysematous lung volume and functional lung volume (FLV) separately on whole lung CT using an image analysis software in 290 patients undergoing major lung resection for cancer between January 2006 and December 2012. The postoperative FLV was predicted by a stepwise multiple regression analysis.
  
  
  RESULTS
  Fourteen patients complained of postoperative dyspnea (complicated group), five of them presented with chronic respiratory failure. The postoperatively measured FLV was significantly lower in the complicated group than in the control group (P < 0.01). The postoperative FLV could be calculated using preoperative variables, including the forced vital capacity, number of resected segments, FLV, and emphysematous lung volume. The predicted postoperative FLV was significantly lower in the complicated group than in the control group (P < 0.01, area under the curve = 0.78; sensitivity 86%; specificity 73%). The predicted postoperative FLV was also useful in distinguishing complicated patients from matched-control patients who had similar preoperative pulmonary function (P = 0.02).
  
  
  CONCLUSIONS
  Postoperative dyspnea is likely accompanied by a collapse of the remaining lung. Quantitative assessment of the lung morphology on preoperative CT is useful to screen for patients at risk of postoperative dyspnea.
authors: Division of Chest Surgery, Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors: Junichi
authors: J
authors: Murakami
authors: Division of Chest Surgery, Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan. Electronic address: kaueda@c-able.ne.jp.
authors: Kazuhiro
authors: K
authors: Ueda
authors: Division of Chest Surgery, Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors: Fumiho
authors: F
authors: Sano
authors: Division of Chest Surgery, Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors: Masataro
authors: M
authors: Hayashi
authors: Division of Radiology, Department of Radiopathology and Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors: Nobuyuki
authors: N
authors: Tanaka
authors: Division of Chest Surgery, Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors: Kimikazu
authors: K
authors: Hamano
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000601:surgery*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality; D012131:Respiratory Insufficiency / Q000000981:diagnostic imaging* / Q000209:etiology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Computed tomography; Dyspnea; Pulmonary resection; Respiratory failure