Performing and Interpreting ABGs Flashcards
What value best reflects acid base balance?
pH
What is pH
A measure of the concentration of hydrogen ions
What is pH relationship to hydrogen ions?
Inverse relationship
What is the normal pH of arterial blood?
Normal is 7.4
Normal range is 7.35-7.45
What is the term for low arterial pH?
acidemia
What is the term for high arterial pH?
Alkalemia
What can happen if a patients pH is out of range?
- Decreased oxygen delivery tissues
- Changes to myocardial contractility
- Electrolyte disturbances
What are the primary organs responsible for maintaining acid base balance?
Lungs + Kidneys
What symptoms are associated with alkalemia?
- Irritability
- Dysrythmias
- Convulsions
- Death
What are the symptoms associated with acidemia?
- Drowsy
- Lethargy
- Coma
- Death
What is the normal range of HCO3 in an ABG?
22-26 mEq/L
What is considered normal oxygenation levels?
80-100 mmHG
What is considered mild hypoxemia?
60-80 mmHg
What is considered moderate hypoxemia?
40-59 mmHg
What is considered severe hypoxemia?
<40 mmHg
What is the mathematical relationship between PaCO2 and pH?
+12 mmHg PaCO2 = -0.1 pH
-12 mmHg PaCO2 = +0.1 pH
What is the mathematical relationship between HCO3 and pH?
+6 mEq/L HCO3 = +0.1 pH
-6 mEq/L HCO3 = -0.1 pH
Where are the primary locations for drawing ABGs?
Radial
Brachial
Femoral
What are the potential barriers to drawing an ABG?
- Surgical shunts or fistulas
- Limb alert bands
- Hematomas
- Infections
- Scar tissue
- Recent failed attempt
What are common complications are associated with ABGs?
- Hematoma
- Vasospasm
- Bleeding/hemorrhage
- Infection
What are less common complications associated with ABGs?
- Vasovagal reaction
- Thrombi/emboli
- Traumatic damage to blood vessels
- Traumatic damage to proximal nerves
- Arteriovenous fistulas
What is the purpose of the modified allens test?
To confirm collateral circulation
When performing a modified allens test, what is the acceptable time period for the palm to flush?
5-15 seconds
