Table 1.

The CASE (Complete, Assess, Severity, Establish) Approach to a Patient with Confirmed or Suspected Chronic Obstructive Pulmonary Disease Who Presents with Worsening Respiratory Symptoms

Complete	A thorough clinical assessment for evidence of underlying COPD and potential respiratory and nonrespiratory concomitant diseases, including consideration of alternative causes for the patient’s symptoms and signs
Assess	Symptoms: Severity of dyspnea using a tool such as the dyspnea visual analog scale; documentation of the presence and characteristics of cough and sputum. Presence of pain and its characteristics
	Signs: Tachypnea, tachycardia, arrhythmia, fever, sputum volume and color, respiratory distress (accessory muscle usage), abnormalities on thoracic examination, and thorough physical examination
Severity	Evaluate by combining symptoms and signs and appropriate additional investigations such as pulse oximetry. If available, obtain laboratory assessments (e.g., CRP), chest X-ray, electrocardiograph, and/or arterial blood gases
Establish	Cause of the event (viral, bacterial, environmental, poor treatment adherence, alternative diagnosis, or other)

Definition of abbreviations: COPD = chronic obstructive pulmonary disease; CRP = C-reactive protein.