Respiratory Flashcards
What does surfactant do?
lowers surface tension, keeping the alveoli from collapsing after exhalation
What does ARDS stand for
Acute Respiratory Distress Syndrome
What is respiratory failure?
Failure in gas exchange due to lung failure
How does respiratory failure occur?
Impaired gas exchange, decreased ventilation or both
What are the two types of respiratory failure and what happens?
TYPE 1 - Hypoxemic - due to failure of gas exchange function of lung.
TYPE 2 - Hypercapneic - hypoxemic due to ventilatiory pump failure (decreased ventilations)
Causes of each type of respiratory failure?
TYPE 1 - Restrictive lung disease, severe pneumonia, atelactasis
TYPE 2 - Upper airway obstruction, laryngospasm, Weak/paralyzed resp muscles, OD, Muscular Dystrophy, Chest wall injury, Asthma
What is a VQ mismatch?
areas of lung ventilated but not perfused or vice versa
Describe the VQ mismatch seen in advanced COPD
CO2 retention due to decreased effective alveolar ventilation leads to a region of the lung not being perfused and thus no gas exchange.
Whats important to remember when oxygenating a potential VQ mismatch patient?
O2 success depends on degree of mismatching present, and in prolonged periods in people w/ chronic lung disease O2 may decrease respiratory drive.
What is impaired diffusion?
gas exchange between the alveolar air and pulmonary blood is impeded because of an increase in the distance of diffusion or a decrease in the permeability or surface area of the respiratory membranes to the movement of gases.
How does increasing flow of O2 treat impaired diffusion?
overcomes decrease in diffusion by establishing a larger alveolar to capillary diffusion gradient.
What is type 2 respiratory failure?
Hypercapnic - unable to maintain sufficient alveolar ventilation to eliminate CO2 –> PaCO2 higher than 50, build-up of CO2 that alters pH as a result
What O2 sats and CO2 would be considered respiratory failure?
arterial PO2 of less than 60% on RA, CO2 of greater than 45mmhg or both.
Why is respiratory acidosis usually present in respiratory failure?
no compensatory mechanism for CO2 retention and thus increased acid production.
Signs of hypoxemia?
Cyanosis, tachypnea, restless, confusion, anxiety, delerium, fatigue, cardiac arrhythmias, HTN.
Initial CVS effects of hypoxemia?
tachycardia, increased CO, increased BP that can lead to arrhythmias
In hypoxemia what happens when the pulmonary vasculature constricts and why does it constrict?
constricts in response to decreased alveolar PO2 leading to hypoxemia and presenting with similar signs as cor pulmonale
What can profound acute hypoxemia cause?
retinal hemorrhages, convulsions, permanent brain damage
Peri arrest findings of someone in hypoxemic respiratory failure?
hypotension, bradycardia due to failure of compensatory mechanisms
What is hypercapnia?
Increased CO2 - adverse consequences due to resp acidosis - leading to depression of cardiac contractility, decreased resp muscle contractility and arterial vasodilation
What happens when etco2 goes above 60?
air hunger and tachypnea
What happens when end tidal increases above 80?
lethargy, disorientation, semi-comatose