title: The Prevention of Respiratory Insufficiency after Surgical Management (PRISM) Trial. Report of the protocol for a pragmatic randomized controlled trial of CPAP to prevent respiratory complications and improve survival following major abdominal surgery.
abstract: Over 300 million patients undergo surgery worldwide each year. Postoperative morbidity - particularly respiratory complications - are most frequent and severe among high-risk patients undergoing major abdominal surgery. However, standard treatments, like physiotherapy or supplemental oxygen, often fail to prevent these. Preliminary research suggests that prophylactic continuous positive airways pressure (CPAP) can reduce the risk of postoperative respiratory complications. However, without evidence from a large clinical effectiveness trial, CPAP has not become routine care. This trial aims to determine whether early postoperative CPAP reduces the incidence of respiratory complications and improves one-year survival following major intra-peritoneal surgery.
  
  
  
  This is an international multicenter randomized controlled trial with open study group allocation. The participants are aged 50 years and over undergoing major elective intra-peritoneal surgery. The intervention is CPAP for at least four hours, started within four hours of the end of surgery.
  
  
  
  The primary outcome is a composite of pneumonia, re-intubation, or death within 30 days of randomization. All participants with a recorded outcome will be analyzed on an intention-to-treat basis. The primary analysis will use a mixed-effects logistic regression model, which includes center as a random-intercept, and will be adjusted for the minimization factors and other pre-specified covariates. Trial Registration: ISRCTN 56012545.
  
  
  
  This is the first proposed clinical effectiveness trial of postoperative CPAP to prevent respiratory complications of which we are aware. The large sample size and multicenter international design will make the result generalizable to a variety of healthcare settings.
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, UK - r.pearse@qmul.ac.uk.
authors.forename: Rupert M
authors.initials: RM
authors.lastname: Pearse
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, UK.
authors.forename: Tom E
authors.initials: TE
authors.lastname: Abbott
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Haslop
authors.affiliation: William Harvey Research Institute, Queen Mary University of London, London, UK.
authors.forename: Tahania
authors.initials: T
authors.lastname: Ahmad
authors.affiliation: Pragmatic Clinical Trials Unit, Queen Mary University of London, London, UK.
authors.forename: Brennan C
authors.initials: BC
authors.lastname: Kahan
authors.affiliation: Department of Surgical Sciences, University of Turin, Turin, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Filipini
authors.affiliation: Critical Care Unit, St. George's University Hospitals, NHS Foundation Trust, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Rhodes
authors.affiliation: Department of Anesthesiology, Intensive Care Medicine and Pain Management, Umberto I Polyclinic Hospital, Sapienza University, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ranieri
mesh_terms: D000005:Abdomen / Q000601:surgery*; D002985:Clinical Protocols; D045422:Continuous Positive Airway Pressure; D006801:Humans; D015337:Multicenter Studies as Topic; D011183:Postoperative Complications / Q000401:mortality / Q000517:prevention & control*; D064792:Pragmatic Clinical Trials as Topic / Q000379:methods*; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D012131:Respiratory Insufficiency / Q000401:mortality / Q000517:prevention & control*; D015996:Survival Rate