Ch. 5 Flashcards
What is the equation for Ve?
Vt x F
Definition of Ve?
Volume of air during normal RR inspired and expired over 1 min. OR rate of respirations per min.
How long do you measure Ve?
15 secs
Inc. rate usually reflects changes in ______ ?
Vent status
Inc. rate =
Hypoxia
Hypercapnia
Inc. temp
Dec. rate =
• CNS depression
• CO2 narcosis (hyper-oxygenation or O2 toxicity)
• Neuromuscular disease involving vent disorders
What is the respiratory exchange ratio (RER)?
The ratio between the volume of CO2 produced (VCO2) divided by the volume of O2 consumed (VO2).
Fun fact
The ratio of the body’s CO2 output to the uptake of CO2 indirectly shows the muscles oxidative capacity to get energy.
RER must be calculated….?
If the inspiratory volumes are used (machine does this).
What is the formula for RER?
VCO2/VO2
What is the normal for RER?
80%
RER ______ as CO2 production ______ ?
Increases ; increases
How do you measure RER?
• RIP- uses transducers to measure pulmonary ventilation by measuring the movement of the chest and abdominal wall.
• Volume displacement spirometer (water seal spirometer).
• Flow sensing spirometer
• O2 & CO2 analyzer
What are some calculations used for RER?
Vt = Ve/F
Ve = Vt x F
What is the usual range for Vt?
400-700 mls in a healthy adult
Ve must be calculated with _____ values to determine adequacy of the vent?
Blood gas (ABG)