Week 8 - Respiratory Flashcards
What is spirometry?
Forced expiration from total lung capacity followed by full inspiration. Best of 3
What are some pitfalls to spirometry?
Trained technician, effort and technique dependent, patient frailty, pain or too unwell.
What would spirometry show in COPD
Obstrucitve. FEV1/FVC <70% FEV1 >80% mild 50-79% moderate 30-49% severe <30% very severe
What are some causes of restrictive spirometry?
Interstitial lung disease (IPF, sarcoidosis), Obesity, pneumonia, poor effort and technique, neuromuscular disease
What effect does smoking have on the lungs?
Reduced filial motility, airway inflammation, mucus and goblet cell hypertrophy, increased protease activity and reduced anti-protease activity. Squamous metaplasia
What might reduced transfer factor show?
Restrictive lung disease
What are some conditions that cause transudate?
Heart failure, cirrhosis, hypothyroidism, renal failure
What are some condition cause exudate?
Malignancy, infection, TB, AI , drug induced
What is obstructive sleep apnoea?
Recurrent episodes of parietal or complete upper airway obstruction during sleep, intermittent hypoxia and sleep fragmnetation
Define chronic bronchitis.
Production of sputum on most days for at least 3 months in at leats 2 years.
Define emphysema
Abnormal, permanent enlargement of the airspaces distal to the terminal bronchioles.
Explain the mechanism of airflow obstruction in COPD
Loss of elasticity and alveolar attachments due to emphysema. The airways collapse on expiration. This leads to air-trapping and so hyperinflation ->increased work of breathing –> breathless.
Goblet cell metaplasia with mucus plugging. Inflammation, thickening of bronchiolar wall.
What drug may cause non-idiopathic pulmonary fibrosis?
Methotrexate
What are the clinical effect of allergies on the airways?
Thickening of the septae, filling of alveolus with fluid, loss of oxygen, air space shadowing on CXR.
chronic exposure: Fibrosis, interstitial destruction from neutrophilic enzymes
What is primary pneumothorax?
Development of sub pleural blebs or bull at the lung apex.
Spontaneous rupture leads to tear in visceral pleura.
Elastic lung collapses
Treat conservatively
What is Secondary pneumothorax?
Underlying lung condition
Weakness in lung tissue
Increased airway pressure
Increased lung elasticity
Aspirate or ICD
What is the pathogenesis of lung cancer?
Chronic irritation/ stimulation of cells by carcinogens
Increased cell turnover
Progressive accumulation of genetic abnormalities in molecules involved in the cell cycle, signalling and angiogenesis
What do Azole drugs do?
Inhibit ergosterol, an essential component of fungal plasma membranes. - Destroy Fingal plasma mem
Define a positive bronchial hypersensitivity test.
Fallen FEV1 by 20% brought about by less than 8mg per ml of methacholine (or histamine or mannitol)
What causes a veil sign on a CXR?
Left upper lobe collapse
What causes the sail sign on CXR?
Left lower lobe collapse
What might a right upper lobe collapse look like on CXR?
Golden S sign
Elevation of horizontal fissure
Elevation of right hilum
What are some methods of measuring lung volume?
Helium dilution
Body plethysmography
Define apnoea.
The cessation or near cessation of airflow for more than 10 seconds. 4% oxygen desaturation
