What is the initial workup for a patient presenting with Shortness Of Breath (SOB)?

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From the Guidelines

The initial workup for a patient presenting with shortness of breath (SOB) should begin with a thorough history and physical examination, followed by targeted diagnostic tests, including assessing vital signs, pulse oximetry, and disease-specific measurements as suggested by the BTS guideline for oxygen use in adults in healthcare and emergency settings 1. The first step in evaluating a patient with SOB is to perform an initial 'ABC' assessment, which includes recording of pulse rate, respiratory rate, and pulse oximetry, as recommended by the BTS guideline 1.

Initial Assessment

  • Assess vital signs including respiratory rate, oxygen saturation, heart rate, blood pressure, and temperature.
  • Pulse oximetry should always be measured in patients with breathlessness or suspected hypoxaemia, with a target saturation range of 94-98% unless otherwise specified, as stated in the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.
  • Disease-specific measurements should also be recorded, such as peak expiratory flow in asthma or blood pressure in cardiac disease.

Diagnostic Tests

  • Basic laboratory tests should include complete blood count to evaluate for anemia or infection, basic metabolic panel to assess electrolyte abnormalities, and cardiac biomarkers like troponin if cardiac causes are suspected.
  • Imaging studies typically start with a chest X-ray to evaluate for pneumonia, pulmonary edema, pneumothorax, or pleural effusions.
  • An electrocardiogram (ECG) should be performed to assess for cardiac arrhythmias or ischemia.
  • Arterial blood gas analysis may be necessary to evaluate oxygenation, ventilation, and acid-base status, particularly in severe cases.
  • Pulmonary function tests can help diagnose obstructive or restrictive lung diseases.
  • For patients with risk factors for pulmonary embolism, D-dimer testing and possibly CT pulmonary angiography should be considered.

Oxygen Therapy

  • Supplemental oxygen should be provided to maintain oxygen saturation above 94% in most patients while the workup proceeds, unless the patient has a condition that requires a different target saturation range, such as COPD or other risk factors for hypercapnic respiratory failure, as stated in the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.

From the Research

Initial Workup for Shortness of Breath (SOB)

The initial workup for a patient presenting with Shortness Of Breath (SOB) involves a comprehensive approach to determine the underlying cause. Key considerations include:

  • Patient history: Although not always indicative of the cause, as noted in a case report 2, a thorough patient history is essential to identify potential underlying conditions such as coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), hypertension (HTN), and gastroesophageal reflux disorder (GERD).
  • Physical examination: Findings such as end-expiratory wheezes and persistent SOB can guide further investigation 2.
  • Diagnostic tests:
    • Imaging studies like CT scans of the chest may be ordered to rule out conditions such as pulmonary embolus (PE) or to identify obstructing masses in the bronchus 2.
    • Bronchoscopy may be performed to investigate suspected foreign bodies or other airway obstructions 2.
  • Consideration of uncommon causes: Beyond common causes like COPD and pneumonia, clinicians should be aware of less common etiologies, as highlighted in 3.

Evidence-Based Approach

An evidence-based approach to evaluating SOB, as discussed in 4, involves considering a broad range of potential causes and tailoring the workup accordingly. This may include:

  • Literature review: Staying updated with the latest research on causes of dyspnea other than reversible airway disease 4.
  • Recommendations for further research: Continuously seeking new evidence to improve diagnostic accuracy and treatment outcomes for patients with SOB 4.

Specific Considerations

In certain cases, such as acute cardiogenic pulmonary edema, specific treatments like noninvasive ventilation (including CPAP or NIPPV) may be beneficial in reducing mortality and improving symptoms, as shown in 5. Additionally, being aware of pitfalls in the evaluation of SOB, as discussed in 6, can help clinicians provide more accurate and timely diagnoses.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Shortness of breath: Looking beyond the usual suspects.

The Journal of family practice, 2016

Research

Evaluation of the patient with shortness of breath: an evidence based approach.

Emergency medicine clinics of North America, 1999

Research

Noninvasive ventilation in acute cardiogenic pulmonary edema.

The New England journal of medicine, 2008

Research

Pitfalls in the evaluation of shortness of breath.

Emergency medicine clinics of North America, 2010

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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