Pleural Space Disease

Question 1

Pleural Effusion

DIscuss the potential clinical findings

Answer 1

• Tachypnoea
• Orthopnoea
• Rapid, shallow breathing
• Increased abdominal effort
• Paradoxical abdominal movement
• Muffled lung/heart sounds - ventrally
• Clinical findings may relate to causative disease
  
  • Fever
  • Heart murmur / gallop rhythm
  • Trauma

Question 2

Describe the phenomenon of

1. Lung Entrapment
2. Trapped Lung

Answer 2

1. Lung entrapment refers to the failure of a lung to re-expand during the removal of pleural effusion. The problem most often occurs with inflammatory or neoplastic effusion and the formation of an immature fibrin layer on the visceral pleura
2. Trapped lung causes failure of lung expansion during removal of pleural effusion as the visceral pleural has become thickened and fibrous, essentially constricting the underlying lung. This is most commonly seen in cases of long standing, chronic effusion.

Question 3

List the definitions of pneumothorax

Answer 3

1. Spontaneous
2. Traumatic
3. iatrogenic
4. Open
5. Closed

Note: Tension pneumothorax can be either spontaneous, iatrogenic or traumatic but is usually closed.

Question 4

Pleural Fluid Physiology

Describe the normal production and movement of fluid through the pleural place

Answer 4

• The rate of fluid production is determined by Starling’s Laws
  
  • Vascular hydrostatic pressure
  • Hydrostatic pressure in the interstitium (approaches zero to slightly negative in the lung)
  • Capilliary oncotic pressure
  • Oncotic pressure within the interstitium (lower than that within the capilliary)
• The factors that promote fluid filtration out of the capilliary bed include the capilliary hydrostatic pressure and the oncotic pressure within the interstitium
• The same factors promote fluid resporption on the venule side (parietal pleura).
• The forces leading to fluid leak on the arteriolar side are slightly higher than those on the venule side leading to a small volume of fluid leaking into and remaining within the pleural space
• The residual fluid is removed via lymphatic drainage.

Question 5

Pleural Fluid Physiology

Describe the mechanisms that cause formation of a transudate

Question 6

Pleural Fluid Physiology

Describe the mechanisms that result in formation of a modified transudate (with examples)

Question 7

Pleural Fluid Physiology

Describe the mechanisms that result in formation of an exudate

Question 8

Pleural Fluid Physiology

Describe the mechanisms that result in formation of a chylous effusion

Question 9

Pleural Fluid Physiology

Describe the mechanisms that result in formation of a haemorrhagic effusion