The Ordering and Impact of Chest Radiography in the Management of Adult Patients with Acute Asthma in Canadian Emergency Departments

• Author / Creator

  Okpere, Ferdinard O

• Objectives: Asthma is a reversible chronic disease of the airway characterized by symptoms of persistent dyspnea, wheezing, chest tightness, cough, and occasional sputum production. Acute asthma is a severe form of asthma, which may result in emergency department (ED) visits, hospitalization or, very rarely, death. Clinicians frequently order chest X-rays (CXR) to rule out comorbid infections (e.g., pneumonia) or pneumothorax/mediastinum complications, however, guidelines are inconsistent with respect to recommendations for ordering CXR for adult patients with acute asthma in emergency departments (ED). This thesis focused on adult patients with acute asthma with the objectives of examining: 1) the literature for CXR ordering in the ED setting; 2) factors associated with CXR ordering, and 3) the impact of CXR ordering on patient outcomes. Methods: Two studies were completed to investigate the ordering of CXR for adult patients with acute asthma in the ED. First, a systematic review was conducted to examine the ordering and outcome of CXR in the ED for adult patients with acute asthma. Second, a Canadian ED dataset was examined for factors associated with CXR ordering and the impact of CXR ordering on the patient’s disposition after ED visits. Results: The systematic review identified 15 published studies and 1 unpublished dataset, conducted in nine countries, including a Canadian study. The mean weighted proportion of CXR ordered upon ED presentation was 60.0% (95% CI: 47.0, 72.2) and was 87.6% (95% CI: 81.0, 93.1) for only admitted patients. The weighted proportion of positive outcomes for CXRs ordered in the ED was 9.5% (95% CI: 7.1, 12.4) and 26.0% (95% CI: 6.1, 53.0) for hospitalized adult patients with acute asthma. Positive CXR outcomes were variably defined among studies and complications were infrequent (e.g., pneumothorax/mediastinum (0.1%) and pneumonia 44 (7.1%)) for adult patients with acute asthma seen in the ED. Factors associated with CXR ordering and the impact of CXR ordering on patients’ disposition were not reported, and this leaves a significant knowledge gap. In a secondary analysis of existing clinical databases of patients discharged with acute asthma involving multiple Canadian EDs, nearly 50% (95% CI: 44.7, 51.3) of adult patients with acute asthma received a CXR. CXR ordering was not associated with most clinical and demographic factors; however, sputum production, fever, and ECG ordering were associated with an increased CXR ordering, and early PEF assessment was associated with reduced CXR ordering. While CXR ordering is also associated with an increased length of stay in the ED, it had no impact on relapse after discharge. Conclusions: The existing literature suggests that a high proportion of adult patients with asthma exacerbations seen in the acute care setting receive a CXR and this is especially so in patients who are admitted. In Canadian EDs, a similarly high proportion of adult patients with acute asthma who are well enough to be discharged home following treatment received a CXR. Radiographic ordering is independent of most clinical/demographic factors, and does not influence future relapse; however, it is associated with a longer length of stay in the ED. Overall, CXR appears over-used in the management of adult patients with acute asthma in the ED, and it seems, physicians’ concern for pneumonia and rare thoracic complications were the main drivers of CXR ordering. Emergency physicians should engage patients in a discussion about the need for a CXR. CXR should be considered in acute asthma only if there are clear signs and symptoms of pneumonia and pneumothorax/mediastinum. Most patients do not require a CXR and given the frequency of presentation, its contribution to ED flow delays, safety (radiation exposure) and cost concerns, reducing CXR ordering in acute asthma is a possible Choosing Wisely® target for emergency practitioners.

• Subjects / Keywords

  • Chest X-ray
  • Emergency Department
  • Ordering
  • Canada
  • Asthma
  • Pneumonia
  • Choosing Wisely®

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3QB9VB02

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.