Respiratory Failure Flashcards
what is type 1 respiratory failure?
PaO2 <8 kPa
PaCO2 normal
what is the pathophysiology behind type 1 respiratory failure?
ventilation-perfusion (V/Q) mismatch
volume of air passing in and out of the lungs is comparatively smaller than the volume of blood perfusing the lungs
what are the causes of type 1 respiratory failure?
- asthma
- congestive cardiac failure
- pulmonary embolism
- pneumonia
- pneumothorax
what is the pathophysiology behind low ventilation/perfusion (V/Q) ratio?
poor ventilation with oxygen but adequeate perfusion by blood
examples of conditions that lead to low V/Q?
- bronchoconstriction (e.g. asthma)
- airway collapse in emphysema
- mucus plug
- congestive cardiac failure
what is the pathophysiology behind high ventilation/perfusion (V/Q) ratio?
adequate ventilation by oxygen but poor perfusion by blood
examples of conditions which lead to high V/Q?
- pulmonary embolism
what is type 2 respiratory failure?
PaO2 <8kPa
PaCO2 >6kPa
what is the pathophysiology behind type 2 respiratory failure?
due to alveolar hypoventilation - lungs fail to effectively oxygenate and blow off carbon dioxide
what are some causes of type 2 respiratory failure?
- obstructive lung diseases - COPD
- restrictive lung diseases - idiopathic pulmonary fibrosis
- depression of the respiratory centre - opiates
- neuromuscular diseases - guillian-barre syndrome, motor neuron disease
- thoracic wall disease - rib fracture
what medication can lead to type 2 respiratory failure?
opiates
what management is considered in uncompensated type 2 respiratory failure which is not responding to oxygen?
non-invasive ventilation (NIV)
what are the two types of type 2 respiratory failure?
compensated and uncompensated
what measurement is used to assess compensation in type 2 respiratory failure?
bicarbonate levels
what would raised bicarbonate levels indicate in type 2 respiratory failure?
compensation
