Respiratory Flashcards
Cause of atypical CAP?
Mycoplasma pneumoniae
What % of chest expansion is the diaphragm responsible for in quiet respiration?
80%
What muscles are used for rapid deep breathing after a sprint?
Diaphragm, external intercostals, SCM
What is the anatomical dead space?
Volume of air occupying the conducting zone of the airways- nostrils to end of terminal bronchioles
What ventilation impairment can barbituate overdose cause?
Hypoventilation due to depression of the respiratory centre of the brainstem
Outline the cough reflex
- Deep inspiration followed by closure of glottis
- Strong contraction of expiratory muscles while glottis remains closed to raise intrathoracic pressure
- Sudden opening of the glottis = explosive discharge of air
What sign do both CF and bronchiectasis show on CT?
Signet ring sign- bronchiole bigger than associated artery
How can CF present?
Newborn screening
Can’t pass meconium ileus
Recurrent chest infections
Malabsorption due to blocked pancreatic ducts
TB drugs and their side effects?
Rifampicin – raises transaminases & induces cytochrome P450 (orange secretions)
- Isoniazid – peripheral neuropathy & hepatotoxicity
- Pyrazinamide – hepatotoxicity
- Ethambutol – visual disturbance
Cause of respiratory alkalosis in PE?
Hypoxaemia triggering peripheral chemoreceptors
Common cause of chronic type 2 respiratory failure?
COPD
Reason for distension of neck veins in PE?
Increased PA pressure makes it more difficult for right ventricle to empty
Differentiate between the function of central and peripheral chemoreceptors
Central - respond to pH changes in CSF - when CO2 diffuses into CSF ventilation increases to counteract chronic hypercapnia
Peripheral - first to respond to severe hypoxaemia
- carotid bodies ( glossopharyngeal) and aortic bodies (vagus)
- feedback to medullary resp centres to increase minutes ventilation
