title: The role of preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis.
abstract: BACKGROUND
  The patients with extremely severe spinal deformity are commonly considered high-risk candidates for surgical treatment because of their underlying lung disease. Currently, little has been reported about the postoperative pulmonary complication events in this population. This retrospective study sought to evaluate preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis.
  
  
  METHODS
  Preoperative forced vital capacity (FVC), FVC ratio, forced expiratory volume at the end of the first second (FEV1), FEV1 ratio, peak expiratory flow (PEF), and PEF ratio were performed and evaluated on 60 patients with extremely severe scoliosis (coronary main Cobb angle ≥100°).
  
  
  RESULTS
  Among the 60 patients, 11 (18.3%), 13 (21.7%), and 22 (36.7%) had severe, moderate, and mild pulmonary dysfunction, respectively. Compared with the moderate and mild scoliosis groups, significant differences were observed in Cobb, FVC, FVC ratio, FEV1, FEV1 ratio, and PEF ratio in the extremely severe scoliosis group. Various postoperative pulmonary complications occurred in nine cases (15%). Patients with severe or moderate dysfunction as measured by the FVC ratio had a higher incidence of postoperative pulmonary complications. A transthoracic procedure was not related to postoperative pulmonary complications, but thoracoplasty significantly increased the incidence of postoperative pulmonary complications (P < 0.001, OR = 20, 95% CI = 3.45-115.97).
  
  
  CONCLUSIONS
  Pulmonary function was impaired in extremely severe scoliosis. Patients with severe restrictive pulmonary dysfunction had a higher incidence of postoperative pulmonary complications. Thoracoplasty was an important risk factor in the prediction of postoperative pulmonary complications.
authors.affiliation: Department of Orthopedic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China. spinepacific@gmail.com.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Lao
authors.forename: Xisheng
authors.initials: X
authors.lastname: Weng
authors.forename: Guixing
authors.initials: G
authors.lastname: Qiu
authors.forename: Jianxiong
authors.initials: J
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D010366:Peak Expiratory Flow Rate; D011183:Postoperative Complications; D011300:Preoperative Care / Q000379:methods; D012129:Respiratory Function Tests / Q000379:methods; D012140:Respiratory Tract Diseases / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012600:Scoliosis / Q000503:physiopathology* / Q000601:surgery*; D012720:Severity of Illness Index; D013905:Thoracoplasty / Q000009:adverse effects; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult