Clinical validation of a risk scale for serious outcomes among patients with chronic obstructive pulmonary disease managed in the emergency department

Abstract

O ne of the most common conditions causing respiratory difficulty in older patients is chronic obstructive pulmonary disease (COPD). It is a respiratory disorder largely caused by smoking, which is characterized by progressive, partially reversible airflow obstruction, systemic manifestations and exacerbations of respiratory distress that increase in frequency and severity over time. 1,2 Exacerbations of COPD, defined as the presence of an increase in at least 2 of breathlessness, sputum volume or sputum purulence, are a frequent cause of emergency department visits. 3 Chronic obstructive pulmonary disease is a major cause of morbidity and mortality in North America and Europe, and the rates of hospital admissions and visits to the emergency department have been rising over the past decade. 4 Many patients with COPD can be treated aggressively for exacerbation of COPD in the emergency department and improve sufficiently to be discharged safely within several hours. Discharging patients with adequate medications can prevent relapse or return to the emergency department because of worsening respiratory symptoms. 3 Many COPD exacerbations, however, are so severe that the patient must be admitted to hospital to ensure adequate management and a safe outcome. We previously showed a relatively low admission rate (38%) from ABSTRACT BACKGROUND: The Ottawa chronic obstructive pulmonary disease (COPD) Risk Scale (OCRS), which consists of 10 criteria, was previously derived to identify patients in the emergency department with COPD who were at high risk for short-term serious outcomes. We sought to validate, prospectively and explicitly, the OCRS when applied by phys icians in the emergency department.

Most important risk factor missing from COPD score

“…The OCRS and the accompanying editorial emphasize that comorbidities are a large determinant of serious outcomes of exacerbations of COPD. 1,2 Physicians are well advised to consider both a patient's multiple morbidities and social situation in admission decisions.…”

An author responds to “Most important risk factor missing from COPD score”

“…My coauthors and I thank Dr. Don Eby for his interest in our article. 1,2 I have 37 years of experience working in a large emergency department and am very familiar with the complexities of making admission decisions. In our paper, my coauthors and I go to great lengths to indicate that medical risk of a poor outcome is only 1 factor to consider, along with many others.…”

“…We see OCRS [Ottawa COPD (chronic obstructive pulmonary disease) Risk Scale] as an important tool to help physicians gauge the medical risk for their patients with COPD, while they determine the need for admission or early follow-up. 2…”

To keep patients with COPD out of hospital, look beyond the lungs

“…4 In this issue of CMAJ, the same author group reports an overall 9.5% rate of short-term serious outcomes that include death, admission to a monitored setting, assisted ventilation, coronary events or readmission. 5 More than 10% of these events occurred in those who were admitted, but 8.3% of them occurred in those who had been initially discharged from the emergency department.…”

“…The primary objective of Stiell and colleagues' study was to validate the Ottawa COPD Risk Scale (OCRS), a measure designed to predict risk of one of these short-term serious outcomes. 5 The authors report that an admission threshold of more than 1 point on the scale would increase sensitivity for these serious outcomes by 50% but require 25% more admissions.…”