Course 04: Respiratory Medicine and Infectious Disease
Lesson 9 of 14. Explore the diagnostic and management frameworks, work through the case, and finish the linked 10-question practice set. Urgent presentations require an emergency-care pathway and review of local professional scope.
Pulmonary embolism risk and assessment
- Suspect PE with abrupt dyspnea, pleuritic pain, tachycardia, syncope, hypoxemia and risk factors such as prior VTE, recent surgery, malignancy or immobility.
- Clinical probability tools (e.g., Wells-based approach) guide D-dimer use and imaging; do not use a negative D-dimer to exclude PE in high clinical probability.
- Shock, marked hypoxemia or syncope with suspected PE demands emergency assessment, not delayed outpatient testing.
Imaging and differential
- CT pulmonary angiography is often used for eligible suspected PE; pregnancy, contrast contraindications and renal impairment may alter the imaging pathway.
- Chest radiograph can help identify competing conditions but does not reliably exclude PE.
- Consider pneumothorax, pneumonia, pericarditis, ACS and musculoskeletal pain with pleuritic chest pain.
Pleural pathology
- Pleural effusions may reflect heart failure, infection, malignancy, PE, liver or renal disease; imaging and diagnostic thoracentesis are indicated selectively.
- Fever, unilateral effusion and pleuritic pain can suggest complicated parapneumonic effusion/empyema needing prompt specialist drainage assessment.
- Avoid invasive procedures without attention to imaging guidance, coagulopathy and local expertise.
Pneumothorax and emergency response
- Sudden unilateral pleuritic pain and reduced breath sounds suggests pneumothorax; assess size and physiological impact.
- Tension pneumothorax with hypotension, severe respiratory distress and unilateral findings is a clinical emergency requiring immediate trained decompression, not waiting for radiography.
- Explain recurrence risk and follow-up requirements after treatment; activity/flight/diving advice is condition- and protocol-specific.
Applied clinical case
A 29-year-old develops sudden pleuritic chest pain, severe breathlessness, hypotension and markedly reduced right-sided air entry.
Show model clinical reasoning and disposition
Tension pneumothorax is possible; activate emergency services for immediate lifesaving decompression by trained professionals. Waiting for a chest radiograph could be fatal.
Clinical self-check
- When is D-dimer inappropriate to rule out PE?
- What indicates complicated pleural infection?
- Why is tension pneumothorax a clinical diagnosis?
Current guidance and further learning
- Canadian Thoracic Society guideline library (external)
- Choosing Wisely Canada: Respiratory medicine (external)