Respiratory failure and ARDS Flashcards
what are the 2 causes of hypoxemic respiratory failure?
ventilation/perfusion mismatch
impaired gas diffusion
what are the 2 determinants of ventilation?
tidal volume and respiratory rate
what are the 3 steps to evaluate respiratory failure
physical
imaging
ABG
what are the causes of hypoxemia in the setting of normal A-a gradient?
altitude (Pbar)
FIO2 (outer space or under water)
PaCO2
True or False: patients who are hypoxemia because of alveolar hypoventilation have hypoxemia respiratory failure
False: Patients with hypoxemia due to alveolar hypoventilation have hypercapnic respiratory failure
What excludes the diagnosis of hypoxemic respiratory failure?
a normal A-a gradient
what kind of patient would have a diagnosis of chronic hypoxemia?
a patient on 2L of oxygen with a 92% saturation
what kind of patient would have a diagnosis of acute on chronic hypoxemia?
a patient normally on 2L of oxygen with good sats now has sats of 82% that improves to 92% on 6L of air
what is the formula for figuring out acute or chronic respiratory failure?
delta pH/ delta PaCO2 (7.4 - pH)/ (40 - PaCO2)
if the equation for respiratory failure equals 0.008 what type of failure is this?
acute respiratory failure
if the equation for respiratory failure equals 0.006 what type of failure is this?
acute on chronic failure
if the equation for respiratory failure equals 0.003 what type of failure is this?
chronic respiratory failure
How do you determine the patient’s oxygenation on a ventilator?
FIO2 and PEEP
why is a PEEP necessary?
because the patient normally has their glottis to create a back pressure and when you intubate, this bypasses the glottis so therefore a synthetic back pressure must be implemented
what is the definition of ARDS?
occurs within 1 week of known clinical insult or worsening respiratory symptoms
it is not fully explained by cardiac failure or fluid overload
