PLEURAL SYNDROMES Flashcards
CLASSIFICATION
- Pleural effusion
- Pleuritic syndrome (“dry”)
- Pleural fibrosis/ Pachypleuritis
- Pneumothorax
Pleura=
a thin membrane that covers the inner surfaces of the
thoracic cavity. It consists of a layer of mesothelial cells
supported by a network of connective and fibroelastic tissue.
1.Parietal pleura
2.Visceral pleura
Anatomy
- Pleural space
- Pleural fluid: 5 -20 ml
Parietal + Visceral Pleura
Parietal pleurae
• cover the inner surface of the thoracic cavity
Visceral pleurae
• cover all surfaces of the lungs
PLEURAL FLUID
Acts as a lubricant to minimize friction between the chest wall and
lung as they move against each other during inspiration and expiration
FUNCTIONS OF PLEURAL FLUID ( total 7 functions)
- spreads into interpleural space
- facilitate movement between the lung and chest wall
- enters from systemic capillaries -> parietal pleurae
- exits via parietal pleural stomas and lymphatic
- depends on the oncotic and hydrostatic pressures within the parietal and visceral pleura as well as the pressure within the pleural space itself
- Hydrostatic pressure in the parietal pleura is similar to systemic circulation (30 cm H2O), whereas that of the
- visceral pleura is similar to the pulmonary circulation (10 cm H2O)
- composition ≈ plasma, but lower in protein (< 1.5 g/dL)
Characteristics of
Normal pleural fluid ( total 6 characteristics)
- clear plasma ultra filtrate
- pH 7.60-7.64
- protein content less than 2% (1-2 g/dL)
- fewer than 1000 WBCs /cmm
- glucose content similar to that of plasma
- LDH level less than 50% of plasma
- Na, K, Ca concentration similar to interstitial fluid
Analysis
- Macroscopic Appearance
- Biochemistry
- Cytology
- Cellularity
- Cultures
Symptoms + signs
Symptoms:
- Pleuritic chest pain
- Dry cough
- Dyspnea
Signs:
- Pleural friction rub
- Particular signs - Pleural effusion syndrome
- Pleural fibrosis syndrome
PLEURITIC CHEST PAIN
Character : a vague discomfort OR sharp pain
Worsens by deep inhalation, chest expansion
Location: depending on affected pleura
• indicates inflammation of the parietal pleura
• usually felt over the inflamed site E.g. or on radiation area
Diaphragmatic pleura → shoulder
Central pleura radiates → back, neck, shoulder
intra-abdominal referred from irritation of 6th intercostal nerve
Special situations:PLEURITIC CHEST PAIN
Missing in interlobar effusion, some chronic effusion
• Continuous, not influenced by respiration in:
• Pleural tumor
• Empyema
• Massive Pleural effusion
PLEURITIC CHEST PAIN : DIFFERENTIAL DIAGNOSIS
Rib fracture = Fixed location+ bone crepitation
• Costochondritis
• Herpes zoster = pain on nerves + vesicles
• Tracheobronchitis - burning over trachea + sputum
• Angina pectoris
• Pericarditis
PLEURITIC COUGH
- “dry”, without sputum production
- Irritative
- Associated usually with pleuritic chest pain
- DETERMINED by: Pleural irritation
DYSPNEA in pleural syndromes
Progressive
• Generated by pain
• Associated tachypnea ±
• Indicates a large effusion (usually > 500 ml)
• In pleural effusions: depends on pleural elasticity, time to accumulation (duration), quantity of the fluid and preexistent underlying pulmonary disease
DYSPNEA in pleural syndromes , Mechanism
Rapid installation of large effusion
• Compression of the lung when large eff.
• Displacement of mediastinum, if exceeds 2000 ml
• Interferences with diaphragmatic musculature activity
• ↓ Vital capacity (VC)
• + Hypoxemia that do not respond to oxygen administration
Pleural friction rub (Auscultation)
Corresponding to the pain location
• Maximum intensity on posterior axillary line
• Present throughout respiratory cycle
• Loudest at end inspiration and early expiration
• Great variability, Seldom present
• Best heard over the area of pleural inflammation
• Described as a
• Rubbing or grating (eg. leather rubbing on leather)
• Harsh
• Dry
• Scratchy sound
• Disappears with breath holding
Pleural effusion
an abnormal accumulation of fluid in the pleural space
Excess fluid results from the disruption of the equilibrium that exists across pleural membranes.
Intrapleural fluid
approximately 0.3 mL/kg of hypooncotic fluid (approximately 1 g/dL protein)
turnover 0.15 mL/kg/hour