respiratory medicine Flashcards
what are the 2 components of respiration?
ventilation
gas exchange
what is ventilation?
airway patency (how wide/narrow)
what is essential for gas exchange?
adequate number of alveoli
no fibrosis of alveolar wall
how will lungs appear on X-ray in health and with fluid?
appear black in health
fluid makes lungs appear white
fluid gathers at costal phrenic angles first
how many lobes does the left lung have?
2 - superior and inferior
how many lobes does the right lung have?
3- superior, middle and inferior
what is a lobectomy?
removal of a lobe so a tumour for example won’t compromise other lobes
what allows change in inter thoracic volume?
ribs
downwards contraction of diaphragm
what is the function of the external intercostal muscles?
elevate ribs
what is the function of the internal intercostal muscles?
depress ribs
what other muscles are involved in respiration?
sternocleidomastoid external and internal oblique transverse abdominus rectus abdominus pectorals major and minor
describe respiratory investigations.
sputum examination CXR - chest radiograph pulmonary function - spirometry VQ scan - ventilation/perfusion mismatch bronchoscopy CT PET MRI for soft tissue lesions
what would green sputum suggest?
pus and infection
what would yellow/white sputum suggest?
excess production of normal sputum
what would blood speckled sputum suggest?
malignancy or inflammation
how is pulmonary function measures?
PEFR - peak expiratory flow rate
FEV1 - forced expiratory volume
FEV1/VC - measures respiratory function
VC - vital capacity
what does a VQ scan look for?
obstructions e.g. tumours or embolism of deep vein thrombosis
when does type 2 respiratory failure occur?
type 2 occurs when ventilation is inadequate to deliver enough oxygen to blood and remove CO2
when does type 1 respiratory failure occur?
type 1 occurs when gas exchange fails through either emphysema, thickening of alveolar wall or VQ mismatch
what is gas exchange?
the ability of alveoli to get oxygen into and CO2 out of blood
what is emphysema?
inadequate alveoli surface area
what is VQ mismatch?
mismatch between where air goes into lungs and where blood goes into lungs
how does thickening of alveolar wall affect gas exchange?
makes diffusion harder
how will inadequate ventilation affect CO2 and O2 levels?
O2 levels fall, CO2 levels rise
what is the airway ability to transfer gas proportionate to?
radius x10^8
when are accessory muscles used?
times of stress/breathing difficulties
what are the symptoms of respiratory failure?
cough wheeze - expiratory noise stridor - inspiratory noise dyspnoea - difficult to breathe pain - general/inspiratory
what are the signs of respiratory failure?
- chest movement should be equal on side with breathing
- rate of respiration should be 12-15 breathes per min
- is air entry symmetrical/reduced?
- vocal resonance should be poor transmission of sound to stethoscope when patient speaks unless fluid or mass in lungs
- percussion note - resonant or dull
what are some ventilation diseases?
- asthma
- chronic obstructive pulmonary disease
- bronchiectasis
what are some gas exchange diseases?
- COPD - emphysema
- pulmonary fibrosis
- ventilation-perfusion mismatch
examples of respiratory disease?
- ventilation disease
- gas exchange disease
- respiratory infection
- inflammatory disease- CF, sarcoidosis
- lung malignancy
