UPSC MainsMEDICAL-SCIENCE-PAPER-II201510 Marks
Q1.

Acute Breathlessness in NRI: Diagnosis & Investigation

A 40-year-old Non-Resident Indian visiting India develops acute, sudden breathlessness one week after landing in India. A resident of USA, he has no such previous history of breathlessness. (i) List the differential diagnosis. (ii) How would you investigate this patient?

How to Approach

This question requires a systematic approach to differential diagnosis and investigation of acute breathlessness in a traveler. The answer should prioritize common and serious causes, considering the patient’s travel history. Structure the answer into two parts: (i) listing the differential diagnoses, categorized by likelihood and severity, and (ii) outlining a logical investigative approach, starting with non-invasive tests and progressing to more invasive ones as needed. Focus on conditions relevant to travel to India from the USA.

Model Answer

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Introduction

Acute breathlessness is a common presenting complaint with a broad differential diagnosis, ranging from benign to life-threatening conditions. In a 40-year-old Non-Resident Indian (NRI) presenting with sudden onset breathlessness one week after arriving in India, a careful consideration of travel-related exposures and pre-existing conditions is crucial. The patient’s lack of prior history suggests an acquired condition triggered by the travel or environment. A systematic approach to diagnosis is essential to ensure timely and appropriate management. This response will outline the potential differential diagnoses and a stepwise investigative plan.

(i) Differential Diagnosis

The differential diagnosis should be categorized based on the likelihood and severity of the condition.

High Probability/Serious Conditions:

  • Pulmonary Embolism (PE): Long-haul travel is a significant risk factor for venous thromboembolism.
  • Pneumonia: Community-acquired pneumonia is common, and atypical pneumonias (e.g., Mycoplasma, Legionella) should be considered.
  • Acute Coronary Syndrome (ACS): Although the patient has no prior history, ACS can present atypically.
  • Severe Asthma Exacerbation: Even without prior history, new-onset asthma or an exacerbation of previously undiagnosed asthma is possible, potentially triggered by environmental allergens or pollutants.

Intermediate Probability:

  • Tuberculosis (TB): India has a high prevalence of TB. Recent exposure, even without prior infection, is possible.
  • Acute Bronchitis: Often viral, but can be bacterial.
  • Pneumothorax: Spontaneous pneumothorax, though less common in this age group, should be considered.
  • Allergic Bronchopulmonary Aspergillosis (ABPA): In individuals with underlying asthma or cystic fibrosis (less likely given the history), exposure to fungal spores can trigger this.

Low Probability:

  • Interstitial Lung Disease (ILD): Less likely with acute onset, but possible.
  • Heart Failure: Unlikely without prior cardiac history, but should be considered if other causes are ruled out.
  • Foreign Body Aspiration: Less likely in this age group, but possible if there's a history of choking.

(ii) Investigative Approach

The investigation should be stepwise, starting with non-invasive tests and progressing to more invasive ones if necessary.

Initial Assessment (Bedside):

  • History: Detailed history focusing on the onset, duration, and character of breathlessness, associated symptoms (chest pain, cough, fever, sputum production, leg swelling), travel details, exposure history, and any relevant medical history.
  • Physical Examination: Vital signs (including oxygen saturation), auscultation of the lungs, assessment for signs of DVT (deep vein thrombosis), and cardiac examination.

Non-Invasive Investigations:

  • Pulse Oximetry: To assess oxygen saturation.
  • Chest X-ray (CXR): To identify pneumonia, pneumothorax, or other lung abnormalities.
  • Electrocardiogram (ECG): To rule out ACS or arrhythmias.
  • Complete Blood Count (CBC): To assess for infection or anemia.
  • Arterial Blood Gas (ABG): To assess oxygenation, ventilation, and acid-base balance.
  • D-dimer: To assess the probability of PE (high sensitivity, low specificity).

Further Investigations (Based on Initial Findings):

Initial Finding Further Investigation
Suspicion of PE (high D-dimer, risk factors) CT Pulmonary Angiogram (CTPA)
Suspicion of Pneumonia Sputum culture and sensitivity, Procalcitonin, Blood cultures
Suspicion of TB Sputum for AFB (Acid-Fast Bacilli), GeneXpert MTB/RIF assay, Mantoux test or IGRA (Interferon-Gamma Release Assay)
Unclear Diagnosis High-Resolution CT (HRCT) of the chest, Bronchoscopy with BAL (Bronchoalveolar Lavage)
Suspicion of ACS Cardiac Enzymes (Troponin), Echocardiogram

Important Considerations: Given the patient’s travel history, consider testing for endemic infections prevalent in India. A thorough environmental exposure history is also crucial.

Conclusion

In conclusion, a 40-year-old NRI presenting with acute breathlessness after travel to India requires a systematic evaluation. Pulmonary embolism, pneumonia, and acute coronary syndrome are high-priority considerations. A stepwise investigative approach, starting with non-invasive tests and guided by clinical findings, is essential. Ruling out serious conditions and considering travel-related exposures are crucial for accurate diagnosis and effective management. Early and appropriate intervention can significantly improve patient outcomes.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

GeneXpert MTB/RIF assay
A nucleic acid amplification test (NAAT) used for the rapid detection of Mycobacterium tuberculosis and rifampicin resistance.

Key Statistics

The incidence of venous thromboembolism (VTE), including PE, is estimated to be 1-2 per 1000 person-years, increasing significantly with prolonged travel.

Source: Heit JA, et al. Trends in the incidence of venous thromboembolism. Circulation. 2012;125(17):2214-2222.

India accounts for approximately 27% of the global TB burden (as of 2023).

Source: World Health Organization (WHO) Global Tuberculosis Report 2023

Examples

Case of Travel-Related PE

A 55-year-old man developed sudden onset breathlessness and chest pain 12 hours after a 14-hour flight. CTPA revealed a PE, and he was successfully treated with anticoagulation.

Frequently Asked Questions

What is the role of D-dimer in evaluating breathlessness?

D-dimer is a fibrin degradation product. Elevated levels suggest the presence of a clot, but it's not specific to PE and can be elevated in other conditions like infection or inflammation. A negative D-dimer can help rule out PE in low-risk patients.

Topics Covered

MedicinePulmonologyRespiratory SystemDifferential DiagnosisInvestigations