Diagnostic flowchart for Chronic Dyspnea

Chronic dyspnea is defined as dyspnea lasting more than one month.

Indications for CT/HRCT include :

• restrictive lung disease.
• preoperative assessment of patients who are being referred for lung reduction surgery.
• patients who have dyspnoea and reduced single-breath diffusing capacity for carbon monoxide without evidence of airflow obstruction.
• patients with chronic dyspnoea in whom the initial evaluation (clinical assessment, CXR and pulmonary testing) is non diagnostic or non revealing.

Difficulty in breathing or Dyspnea

Dyspnea is uncomfortable awareness of breathing.
Or
Shortness of breath
Or
Difficulty in breathing

Causes:

Acute-

• Asthma
• Pneumonia
• Pulmonary edema
• Pneumothorax
• Pulmonary embolism
• metabolic acidosis
• Panic attacks

Pulmonary-

• Airflow obstruction diseases- Asthma, COPD, upper airway obstruction
• restrictive lung diseases- interstitial lung disease, pleural thickening or effusion, respiratory muscles weakness, obesity
• Pneumonia
• Pulmonary edema
• Pneumothorax
• Pulmonary embolism

Cardiac-

• myocardial ischaemia
• congestive heart failure
• valvular obstruction
• arrythmias
• cardiac tamponade

Metabolic-

• acidosis
• hypercapnia
• sepsis

Hematologic-

• anaemia
• methemoglobinemia

Psychiatric-

• anxiety

Episodic dyspnea can occur in following cases-

• congestive cardiac failure
• asthma
• acute or chronic bronchitis
• recurrent pulmonary emboli