Pulmonary Embolism vs. Gastroenteritis: Symptom Comparison
Pulmonary embolism (PE) and gastroenteritis ("stomach flu") generally present with distinctly different symptoms, though there can be some overlap that may lead to diagnostic confusion in certain cases.
Key Symptom Differences
Pulmonary Embolism Presentation
The most common clinical features of PE include:
- Dyspnea (shortness of breath) - present in up to 70% of cases 1
- Tachypnea (rapid breathing >20/min) 1
- Pleuritic chest pain 1
- Apprehension/anxiety 1, 2
- Tachycardia 1, 2
- Cough 1, 2
- Hemoptysis (coughing up blood) 1, 2
Gastroenteritis Presentation
Typical symptoms of gastroenteritis include:
- Nausea and vomiting
- Diarrhea
- Abdominal pain/cramping
- Fever
- Malaise
Potential Diagnostic Confusion
While these conditions typically present differently, there are several scenarios where confusion may occur:
Nausea and vomiting in PE: Although not among the most common symptoms, PE can sometimes present with nausea and vomiting, particularly in pediatric patients or those with large emboli 3. This can lead to misdiagnosis as gastroenteritis.
Abdominal pain: Some patients with PE may experience abdominal discomfort, especially with right heart strain, which could be confused with the abdominal pain of gastroenteritis.
Non-specific symptoms: Both conditions can present with general malaise and fatigue.
Critical Distinguishing Features
To differentiate between these conditions:
Respiratory symptoms: The presence of dyspnea, tachypnea, or pleuritic chest pain strongly suggests PE rather than gastroenteritis 1, 2. The British Thoracic Society guidelines emphasize that the absence of dyspnea, tachypnea, and pleuritic pain together virtually excludes PE 1.
Risk factors: Consider PE risk factors including recent immobilization, history of DVT/PE, malignancy, oral contraceptive use, pregnancy, or recent surgery 1, 2.
Vital signs: Tachycardia and tachypnea are more characteristic of PE than uncomplicated gastroenteritis 1.
Diagnostic Approach When Symptoms Overlap
When symptoms are ambiguous:
Apply clinical prediction rules: Use validated tools like the Wells score or revised Geneva score to estimate PE probability 2.
Consider D-dimer testing: For patients with low or intermediate probability of PE 2.
Imaging: CTPA is the first-line imaging test for suspected PE with sensitivity of 83% and specificity of 96% 2.
Special Considerations
Pediatric oncology patients: These patients may present with atypical PE symptoms, including isolated nausea and vomiting 3. Maintain high suspicion in this population.
Elderly patients: May have atypical presentations of both conditions.
Conclusion
While PE and gastroenteritis typically present with different symptom clusters, clinicians should be aware that PE can occasionally present with gastrointestinal symptoms. The presence of respiratory symptoms (dyspnea, tachypnea, pleuritic pain) strongly suggests PE, while their absence makes PE highly unlikely 1. When diagnostic uncertainty exists, appropriate risk stratification and testing should be pursued to avoid missing a potentially fatal PE.