Breathlessness- extra from lectures Flashcards
Flow volume loops
Plot of Inspiratory and Expiratory Flow (y-axis) against volume (x-axis)
Maximally forced inspiratory and expiratory manoeuvres
Useful for identifying the location of obstruction
Dynamic/variable extra-thoracic obstruction
Functional vocal cord paralysis
Extra-thoracic tracheomalacia
Polychondritis
Dynamic/Variable intra-thoracic obstruction
Tracheomalacia
Tracheal lesions
Fixed upper airway obstruction
Tracheal stenosis
Extra-thoracic compression (tumour/goitre)
Peripheral/lower airways obstruction
COPD
Asthma
Brochiolitis
Different measurements of lung volume
Tidal Volume = Volume of air in and out during normal breathing
Functional Residual Capacity = Volume of air in lungs at end of normal expiration
Total Lung Capacity = Volume of air in lungs after full inspiration
Residual Volume = Gas remaining in the lungs after full expiration
Vital Capacity = Volume of air expelled by a full expiration from position of full inspiration
Conditions causing increased and decreased lung volume
Increased lung volume- airflow obstruction (particularly raised residual volume), Emphysema
Decreased lung volume- Restrictive lung disease (lung parenchyma or extra-pulmonary)
TLCO and KCO
TLCO- Transfer factor for the Lung Carbon Monoxide. Measures the total ability of the lungs to transfer gas into the blood stream
KCO- transfer coefficient. Gas transfer per unit volume, reflects alveolar volume in the lung
What causes a reduced TLCO or KCO
Anything disrupting the alveolar membrane or reducing pulmonary capillary volume.
Conditions: Emphysema, Interstitial lung disease, Pulmonary hypertension, Pneumonia, Multiple PTE, Anaemia, Low cardiac output
What causes TLCO or KCO to be increased
By anything increasing the pulmonary capillary volume
- Asthma (decreased intrathoracic pressure)
- Alveolar haemorrhage (recent)
- Left to right shunts
- Polycythaemia
- Exercise
Conditions which cause the gas transfer (TLCO) to be reduced but the kco to not change
- Pneumonectomy
- Chest wall disease
TLCO and KCO: Airflow obstruction
Low TLCO : emphysema//bronchiolitis obliterans
Normal TLCO: COPD/bronchitis but no emphysema
Raised TLCO : Asthma
TLCO and KCO: Restriction (reduced FVC and reduced lung volume)
Low TLCO : ILD
Raised KCO: Extra pulmonary Restriction (obesity, pleural effusion, kyphoscoliosis, muscular weakness, pulmonary haemorrhage)
TLCO and KCO: Restriction (reduced FVC and reduced lung volume)
Low TLCO: ILD
Raised KCO: Extra pulmonary Restriction (obesity, pleural effusion, kyphoscoliosis, muscular weakness, pulmonary haemorrhage)
Isolated reduced TLCO with normal spirometry
- May suggest pulmonary vascular disease
- Anaemia
- CPFE
Raised TLCO and KCO
Polycythaemia, left to right shunt or pulmonary haemorrhage
Type 1 respiratory failure conditions
Pulmonary fibrosis
Pulmonary embolism
Pneumothorax
Acute severe asthma- only life threatening asthma is type 2
Difference between pneumonia and COPD on an x-ray
Pneumonia: consolidation on one side, wheeze
COPD: symmetrical, hyperinflated (bigger)
Heart failure- chest x-ray
In chronic heart failure you get pleural effusion
Pleural effusion has a meniscus
There may be an absent costophrenic angle due to fluid
How does the trachea move in a chest x-ray
Pleural effusion: Trachea shifts away
Lung collapse: Trachea shifts towards
Emphysema: chest x-ray
Hyperinflation
Narrow mediastinum
Hyperluency
Bullae
How many ribs cover the lungs
5th-7th rib hits the diaphragm
In emphysema it is more
Tension pneumothorax treatment
Air is let into the pleural space which causes a pressure imbalance
Put a needle into the 2nd intercostal midclavicular line to treat it
Then put the pleural drain int the 5th intercostal space midaxillary line
What investigation confirms the diagnosis of pulmonary embolism
CT pulmonary angiogram