Chest pain DDx

Question 1

What is the difference between a pneumothorax and a tension pneumothorax?

Answer 1

• Pneumothorax: abnormal collection of air in the pleural space without a buildup of pressure
• Tension pneumorthorax: a pneumpthorax due to trauma to the lung
  
  • as the patient continues to breathe they pull air into the new space → pressure to build → affects nearby organs → tension pneumothorax

Question 2

Causes of pneumothorax’s

Answer 2

Pneumothorax causes:

• Primary: no apparent cause
  
  • Tall, thin (marfans), smokers
• Secondary: in the presence of lung disease; smoking, COPD, asthma, TB
• Traumatic

Question 3

Treatment of Pneumothoraces?

Answer 3

• Primary:
  
  • Small (<2cm): will resolve without tx, monitor only
  • >2cm or SOB: chest drain
• Secondary:
  
  • ​>50yrs or >2cm rim +/- SOB: Chest drain inserted, otherwise air aspirated with a syringe
  • Admit for minimum 24hours***
  • Surgery may be required if this is unsuccessful or repeated episodes. (pleurodosis or pleurectomy)

Question 4

Characteristic features of a pneumothorax:

Answer 4

• dyspnoea/SOB
• Sudden, stabbing Chest pain (often pleuritic)
• Diaphoresis
• Tachypnoea
• Tachycardia

P-THORAX: Pleuritic pain, Tracheal deviation, Hyperresonance, Onset sudden, Reduced breath sounds (and dyspnea), Absent fremitus, X-rays show collapse.

Question 5

Difference between pneumothorax on xray?

Answer 5

• Tension pneumothorax:
  
  • Displacement of the mediastinum to the contralateral side
  • flattening of the cardiac border on the ipsilateral side
• Spontaneous pneumothorax:
  
  • No displacement of the mediastinum as there is no pressure issue

Question 6

Pleural effusions are ______________ and are usually classified as either ______ or ______

Answer 6

Pleural effusions are accumulations of fluid within the pleural space and are usually classified as either transudates or exudates

By the origin of the fluid:

• Serous fluid (hydrothorax)
• Blood (haemothorax)
• Chyle (chylothorax)
• Pus (pyothorax or empyema)
• Urine (urinothorax)

By pathophysiology:

• Transudative pleural effusion
• Exudative pleural effusion

Question 7

What is the difference between a transudate or an exudate.

Hint: it’s based on how that fluid got into the space in the first place

Answer 7

Transudate (<30g/L protein): pushed through capillary due to high capillary pressures. **Doesn’t contain proteins** Change in hydrostatic pressure

• Heart failure
• Hypoalbuminaemia (Cirrhosis, nephrotic syndrome, malabsorbtion)
• Meigs Syndrome

Exudative (>30g/L protein): fluid that leaks due to inflammation around the cells of the capillaries . **Contains proteins** Inflammatory

• infection: pneumonia, TB, subphrenic abscess
• Connective tissue disease: RA, SLE
• Neoplasia: lung cancer, mets, mesothelioma
• Pancreatitis
• Lupus

Question 8

Features of a pleural effusion

Answer 8

• dyspnoea/SOB, non-productive cough or chest pain
• Dullness to percussion, reduced breath sounds and reduced chest expansion

Question 9

How to investigate pleural effusions

Answer 9

• Imaging
  
  • PA CXR on all patients
  • USS recommended
  • Contrast CT is now increasingly performed to investigate the underlying cause
• Pleural aspiration (rec. with USS)
  
  • Fluid sent for pH, protein, LDH, cytology and microbiology

Question 10

What is the purpose of Light’s Criteria?

Answer 10

To help distinguish between a transudate and an exudate when the protein is between 25-35g/L

“An exudate is likely if at least one of the following criteria are met:”

• pleural fluid protein divided by serum protein >0.5
• pleural fluid LDH divided by serum LDH >0.6
• pleural fluid LDH more than two-thirds the upper limits of normal serum LDH

Question 11

Features of pericarditis, emphasis on the distinctive features

Answer 11

• Chest pain (may be pleuritic) that is often relieved by sitting forward
• Non-productive cough
• SOB
• Flu-like symptoms
• Pericardial rub
• Tachypnoea
• Tachycardia

Question 12

Common causes of Pericarditis

Hint: not all are infective causes!

Answer 12

• Viral infections (coxsackie)
• TB
• Trauma
• Post MI
• Connective tissue disease
• Hypothyroidism
• Malignancy

Question 13

What two distinctive things do you expect to see on an ECG in a patient with pericarditis?

Answer 13

1. Widespread ‘saddle-shaped’ ST elevation
2. PR depression: most specific marker for pericarditis

Question 14

What specific causes of pericarditis can cause constrictive percarditis? What other pathology can this often be confused with?

Answer 14

• Any cause of pericarditis can actually cause constrictive pericarditis, however TB is a particularly common cause
• This can often be confused with cardiac tamponade, however there are some key differences!

Question 15

What would you see on CXR in a patient with constrictive pericarditis?

Answer 15

Pericardial calcification

(* which would NOT be seen in cardiac tamponade)