Pulse Oximetry
What is the normal digital delay on a pulse oximeter
10 sec from periphery to display
What are the two ways blood is transported in the body
Dissolved in plasma and bound to HgB
What does SaO2 stand for and how is it obtained
Saturated oxygen in the arteries(little a)and is obtained with an ABG
The oxyhemoglobin disassociation curve has to with relationship between SaO2 and this...
PaO2 Partial pressure of oxygen
How is transcutaneous CO2 collected and where should it be placed
A sensor ( Severinghaus sensor)that warms the capillary blood flow through the skin ie: forearm, chest, stomach
What is considered below normal SpO2
Below 90%
How much O2 is bound to HgB
98%
What does SpO2 stand for
Saturated oxygen estimated by a pulse oximeter
At what point on the curve does the oxygen strongly gravitate to HgB and what direction does it shift
Hint : higher than 65 and lower than 75 mmhg
70 mmhg and shifts up and to the left
How is CO2 collected from EtCO2 cannula
A nasal oral cannula that collects end of expired air and shows CO2 levels at the capillary membrane using " flow verses time" waveform.
It uses an infrared carbon dioxide gas analyzer
How do you determine the SaO2 ratio
( remember the apartment building)
How many sites are filled divided by how many sites are available
4 sites all filled =100% Oxyhemoglobin
3 site filed=75%
2 sites filled=50%
1 site filled=25%
1-2%
What does PaO2 stand for
Partial Pressure of Oxygen collected with an ABG
P means partial pressure
little a means artery
If affinity of oxygen is weak at 10-50mmhg,what direction does the curve move
Down and to the right
What is normal EtCO2
45mmhg
How does a pulse oximeter determine SpO2
two lights wave lengths and absorption of light through the blood vessels
How many oxygen molecules can bind to each hemoglobin molecule. ( Remember the apartment complex)
Four
Describe cyanosis as an clinical indicator of hypoxemia
Bluish grey color around nose, mouth and nail beds
Name some patients whose CO2 should be monitored
Pediatrics ,hypoventilation,, COPD patients with CO2 retention, neuromuscular diseases, trach patients
What is the most important patient feature to insure an accurate reading on a pulse oximeter
Patient perfusion
A hemoglobin molecule that is saturated with oxygen is called ...
Oxyhempglobin
Which of these values are NOT collected by capnography
Ventilation
perfusion
metabolism
cyanosis
Cyanosis
What is the window of accuracy on a pulse oximeter
70%
What does Oxygen Affinity mean
The willingness of the hemoglobin to accept Oxygen
What information is collected from EtCO2 cannula
CO2 production and respiratory patterns
How is the reading on a pulse oximeter change if a patient is on supplemental oxygen
It will read higher than the actual saturation
The wave form on the waveform of capnography is NOT affected on a patient with COPD
True or False
False
Because they have reduced Vt, there is no clear distinction of exhalation to be measured
What is portion of exhaled air from the back of the mouth and throat called
Dead space