Respiratory failure (ARF) Flashcards
Acute respiratory failure is not a disease but a what ?
Symptom
Why is acute respiratory failure a symptom?
because respiratory failure reflects insufficient lung function, usually being caused by an underlying condition
As mentioned previously acute respiratory failure is usually a result from an underlying condition, remembers its a symptom, not a disease, can you give examples to what others systems can cause respiratory failure ?
cardiac system
Centeral nervous system
how does respiratory failure occur ?
when oxygenation, ventilation or both are inadequate
What is the term called when you do not have enough oxygen in the blood ?
Hypoxemia
What is the term called when you have too much carbon dioxide in the blood called ?
hypercapnia
what are the 2 ways you can get respiratory failure?
either from the lack of oxygen
or
from having too much carbon dioxide
can patients have both types of respiratory failure at the same time ?
yes
how does acute respiratory failure present itself in a patient?
usually tachycardia, low blood pressure, increase respiratory rate and confusion may occur
how does chronic respiratory failure present itself in a patient?
develops slowly over days and weeks, generally starts off stable changes into changes that are no longer compensatory for the patient
its very common sense to know that when a patient is having a hard time breathing because hypoxemic respiratory failures is the depletion of air, but do you think hypercapnic respiratory failure does the same for the patient?
no, its not from the lack of air, its from the lack of explection of air
what are the 4 ways that hypoxemic respiratory failure occurs ?
V/Q mismatch
Shunt
Diffusion Impairment
Alevolar hypoventilation
what is v/q mismatch for hypoxemic respiratory failure, explain to me what this is ?
v/q mismatch is when ventilation ( airflow ) or perfusion ( blood flow ) in the lungs is impaired,
meaning its preventing the lungs from optimally delivering oxygen to the blood
what are some causes of v/q mismatch ?
lung disease
- COPD, asthma, atelectasis
Pain
- increased stress causes metabolic rate, meaning it increases the need of o2
atelectasis
pulmonary embolism
what is the first treatment for v/q mismatch, or in general when a patient is experiencing hypoxemic respiratory failure?
sit them up, provide 02 and treat the underlying cause
what are some common diagnostic methods we can use on a patient to see hypoxemic respiratory failure?
ABGs
pulse ox
LOC assessment
respiratory assessment
what is a shunt in the terms of hypoxemic respiratory failure ?
blood leaves the heart without gas exchange - extreme v/q mismatch
in other terms, blood will leave the heart however it will not receive fresh oxygen and not get rid of the carbon when trying to make that exchange
what’s the difference between shunt and a v/q mismatch?
v/q mismatch is the imbalance between ventilation and blood flow
shunt is from the result of reduced ventilation relate to blood Flow, leading to decreases oxygenation
what are 3 main causes of shunting in hypoxemic respiratory failure?
anatomic shunt ( heart )
- ventricular septal defect
intrapulmonary/capillary shunt
- blood flows through pulmonary capillaries without exchanging gases
- pneumonia for example
mechanical ventilation with high levels of oxygen
what is diffusion impairment of hypoxemic respiratory failure?
gas exchange across alveolar - capillary membrane is compromised by scarring of alveoli due to fibrosis or fluid in alveoli
gas exchange is happening so like oxygen and carbon dioxide are being able to change, however due to scarring in the alveoli, its preventing that, so think of like if scars were there, this wouldn’t be happening
what is a classical sign of diffusion impairment ?
you are breathing fine when resting, but then the second you do any movement or exercise, hypoxemic
patho behind this is because when you move, cardiac output causes blood to flow faster to the heart and there is no time to diffusion
what is alveolar hypoventilation in hypoxemic respiratory failure?
its a decreased ventilation learning to increase CO2 in the body
- mainly its associated with hypercapnic respiratory failure but since there is no air being pumped through, thats why its hypoxemic