Houston, We Have Results
The ARDS classification of a P/F ratio of 125
What is moderate ARDS?
The components of the alveolar air equation
What is FiO2 X (PB - PH20) - (PACO2 / RQ) ?
where RQ may be 0.8
Define gas diffusion
What is gas molecules moving across a membrane from high pressure areas to low pressure areas?
True or false: membrane thickness affects molecular ability to diffuse across it
What is true?
COPD, restrictive lung disorders, and conditions resulting in hypoventilation are examples of this type of shunt
What is an alveolar shunt?
The ventilator tubing was dirty and changed out with a longer circuit. The patient now presents acidotic because this has occurred
What is increased dead space and/or the need for increased minute ventilation?
How to calculate the A-a gradient, where 'A' is the partial pressure of oxygen in the alveoli and 'a' is the partial pressure of oxygen in the arteries
What is PAO2 - PaO2?
Five factors that affect the loading and offloading of oxygen
What is blood pH, body temperature, erythrocyte concentration, structure/shape of hemoglobin, and adverse hemoglobin chemical combinations?
What is alkalosis? May also accept low body temperature.
This shunt sends venous blood from the right heart to the left heart without gas exchange
What is a physiologic shunt?
The reason(s) a mountain hiker requires deeper breathing and may encounter varying levels of hypoxia in higher altitudes, similar to that of pilots without added oxygen
What is the barometric pressure drops and therefore the arterial oxygen content is decreased and may lead to hypoxemia?
What is the P/F ratio of a patient with a PaO2 of 89 mm Hg using an FiO2 of 45%
What is 197.78, or 198?
Acidity affects the uptake of oxygen by...
What is reducing the ability to obtain oxyhemoglobin?
This condition hardens and changes the shape of hemoglobin, and increases the risk of clot development
What is sickle cell?
This combination with hemoglobin increases the affinity for oxygen but loses oxygen binding capacity due to the presence of ferric ions
What is methemoglobin?
The presence of this is why young infants may have a left shift on the oxyhemoglobin curve with less tissue oxygen unloading
What is fetal hemoglobin?
The formula for arterial oxygen content that is the sum of oxygen that is actually combined to Hb and dissolved in plasma
What is (0.003 X PaO2) + (1.34 X Hb X SaO2) ?
True or false: tissue hypoxia does not occur when PaO2 is normal
What is false?
(think of blood loss or variant Hb)
The presence of this easily displaces true oxygen carrying capacity by half because it has a greater affinity for hemoglobin binding and will still show good oxygen saturations
What is carboxyhemoglobin?
This may be indicative of a low V/Q and suggest ventilation is less than normal while perfusion may be unaffected or greater than normal
What is atelectasis or alveolar collapse?
What is a normal A-a gradient?
CO2 is primarily removed from the body through this event
What is hydrolysis in erythrocytes where carbonic anhydrase breaks down CO2 into HCO3 for buffering, equilibrium, and diffusion?
Septic shock may increase lactic acidosis due to...
What is an unmet oxygen demand leading to anaerobic metabolism and the accumulation of lactic acidosis?
Describe the 50/50 rule
What is an estimation of significant shunt presence when the patient is on more than 50% FiO2 but their PaO2 is less than 50 mm Hg?