Respiratory Failure Flashcards
Define type 1 and type 2 respiratory failure?
Type 1 respiratory failure O2 less than 8.0kPa
In Type 2 = 2 things wrong
pO2 less than 8.0kPa
pCO2 greater than 6.5kPa
What are the implications of high arterial pCO2?
Acute: Respiratory acidosis, CO2 forms carbonic acid. Can lead to unconsciousness and death.
Chronic: Chronically high levels will desensitize a persons hypercapnic drive to breath therefore they rely on their hypoxic drive
It is therefore dangerous to give high flow O2 in patients with COPD as it will cause the respirartory rate to drop and cause increased CO2 retention.
What are the causes of ventilatory failure?
Neurogenic:
Any damage to the respiratory centre in the medulla oblongata or pons e.g pontine demyelination in rapidly developed hyponatraemia, damage to the ant. horn cells in ALS, opiate overdose, Guillian-barre.
Neuromuscular:
Myasthenia Crisis: Dysfunction in the neuromuscular junctions supplying the respiratory muscles causing ventilatory failure.
Chest Wall Problems:
Fractures/Trauma
Too painful to properly ventilate.
Damaged nn supply to the respiratory muscles:
Diaphragm, External intercostals,
Accessory muscles: Scalenes and Sternocleidomastoid
Respiratory problems: Fibrosis COPD Severe Asthma Tb Sever Pneumonia Lobar collapse Huge PE
Outline the effect of chest wall and spinal deformity on respiratory failure?
Deviation in the shape of the chest wall away from normal impacts respiratory function as it can limit chest expansion.
Kyphoscoliosis: Over curved and s shaped spine. Impedes proper chest expansion and therefore can cause type 1 respiratory failure.
How is ventilatory failure managed?
A to E assessment
Type 1 give O2 therapy.
Treat underlying cause.
Consider providing assisted ventilation. Non invasive ventilation (CPAP or BIPAP) or endotracheal tube.
What are the metabolic causes of an acidosis?
Ketoacidosis (DKA)
Ingestion (salicylate poisoning)
Lactate (sepsis)
Ureamia
KIL U mnemonic
