title: Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery.
abstract: OBJECTIVE
  Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior).
  
  
  METHODS
  We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique.
  
  
  RESULTS
  The mean age of the patients was 56 ± 13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6 ± 0.6 L) and FVC (2.0 ± 0.7 L) with maintenance of FEV1/FVC of 0.8 ± 0.2 in both groups. The maximum intra-abdominal pressure values were similar (p=0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed.
  
  
  CONCLUSIONS
  Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Roberto de
authors.initials: Rd
authors.lastname: Cleva
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marianna Siqueira de
authors.initials: MS
authors.lastname: Assumpção
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Flavia
authors.initials: F
authors.lastname: Sasaya
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Natalia Zuniaga
authors.initials: NZ
authors.lastname: Chaves
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marco Aurelio
authors.initials: MA
authors.lastname: Santo
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fló
authors.affiliation: Gastroenterology Department, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Adriana C
authors.initials: AC
authors.lastname: Lunardi
authors.affiliation: Geriatric Medicine, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Jacob Filho
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000503:physiopathology*; D011312:Pressure; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D013147:Spirometry; D018709:Statistics, Nonparametric; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology