title: Postoperative pulmonary complications following major elective abdominal surgery: a cohort study.
abstract: BACKGROUND
  Postoperative pulmonary complications (PPC) are an under-reported but major cause of perioperative morbidity and mortality. The aim of this prospective, contemporary, multicentre cohort study of unselected patients undergoing major elective abdominal surgery was to determine the incidence and effects of PPC.
  
  
  METHODS
  Data on all major elective abdominal operations performed over a 2-week period in December 2014 were collected in six hospitals. The primary outcome measure of PPC at 7 days was used. Univariate and multivariate analyses were performed to investigate how different factors were associated with PPC and the effects of such complications.
  
  
  RESULTS
  Two hundred sixty-eight major elective abdominal operations were performed, and the internal validation showed that the data set was 99 % accurate. Thirty-two (11.9 %) PPC were reported at 7 days. PPC was more common in patients with a history of chronic obstructive pulmonary disease compared to those with no history (26.7 vs. 10.2 %, p < 0.001). PPC was not associated with other patient factors (e.g. age, gender, body mass index or other comorbidities), type/method of operation or postoperative analgesia. The risk of PPC appeared to increase with every additional minute of operating time independent of other factors (odds ratio 1.01 (95 % confidence intervals 1.00-1.02), p = 0.007). PPC significantly increase the length of hospital stay (10 vs. 3 days). Attendance to the emergency department within 30 days (27.3 vs. 10.6 %), 30-day readmission (21.7 vs. 9.9 %) and 30-day mortality (12.5 vs. 0.0 %) was higher in those with PPC.
  
  
  CONCLUSIONS
  PPC are common and have profound effects on outcomes. Strategies need to be considered to reduce PPC.
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Patel
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Hadian
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Aysha
authors.initials: A
authors.lastname: Ali
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Broadley
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Evans
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Horder
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Marianne
authors.initials: M
authors.lastname: Johnstone
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Fiona
authors.initials: F
authors.lastname: Langlands
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Jake
authors.initials: J
authors.lastname: Matthews
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Prithish
authors.initials: P
authors.lastname: Narayan
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Priya
authors.initials: P
authors.lastname: Rallon
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Roberts
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK.
authors.forename: Sonali
authors.initials: S
authors.lastname: Shah
authors.affiliation: West Midlands Research Collaborative, Academic Department of Surgery, School of Cancer Sciences, University of Birmingham, Birmingham, B15 2TH UK ; Nottingham Oesophago-Gastric Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: Ravinder
authors.initials: R
authors.lastname: Vohra
keywords: Morbidity; Postoperative; Pulmonary complications; Surgery