title: A pilot audit of a protocol for ambulatory investigation of predicted low-risk patients with possible pulmonary embolism.
abstract: BACKGROUND
  Patients with possible pulmonary embolism (PE) commonly present to acute medical services. Research has led to the identification of low-risk patients suitable for ambulatory management. We report on a protocol designed to select low-risk patients for ambulatory investigation if confirmatory imaging is not available that day.
  
  
  METHODS
  The protocol was piloted in the Emergency Department and Medical Assessment Area at the Royal Infirmary of Edinburgh. We retrospectively analysed electronic patient records in an open observational audit of all patients managed in the ambulatory arm over five months of use.
  
  
  RESULTS
  We analysed 45 patients' records. Of these, 91.1% required imaging to confirm or refute PE, 62.2% received a computed tomography pulmonary angiogram (CTPA). In 25% of patients, PE was confirmed with musculoskeletal pain (22.7%), and respiratory tract infection (15.9%) the next most prevalent diagnoses. Alternative diagnoses was provided by CTPA in 32% of cases. We identified no adverse events or readmissions but individualised follow-up was not attempted.
  
  
  CONCLUSIONS
  The data from this audit suggests this protocol can be applied to select and manage low-risk patients suitable for ambulatory investigation of possible PE. A larger prospective comparative study would be required to accurately define the safety and effectiveness of this protocol.
authors.affiliation: Department of Emergency Medicine, Royal Infirmary of Edinburgh, UK. alexander.mcdonald@nhs.net
authors.forename: A H
authors.initials: AH
authors.lastname: McDonald
authors.forename: R
authors.initials: R
authors.lastname: Murphy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D000792:Angiography; D002985:Clinical Protocols; D003695:Delivery of Health Care; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000209:etiology*; D019370:Observation; D018579:Patient Selection; D010865:Pilot Projects; D011655:Pulmonary Embolism / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012141:Respiratory Tract Infections / Q000209:etiology*; D012189:Retrospective Studies; D012306:Risk; D012606:Scotland; D014057:Tomography, X-Ray Computed; D055815:Young Adult