ABG introduction & overview
ABGs can tell us what about our patients?
What is how well they are oxygenating, ventilating, and maintaining acid-base balance.
(Castro et al., 2024)
A blood gas would be considered alkalotic when the pH levels rise above this number..
What is 7.45
**Memory tool**
Think alka seltzer.. it fizzes UP (above normal pH range) when you drop it into a glass of water.
A blood gas would be considered acidotic when the pH falls below this number..
What is 7.35
**memory tool**
“A before B: Acidosis is Below 7.35”
This ABG value reflects the metabolic comment of acid base balance and is balanced by the kidneys..
What is HCO3 (Bicarbonate).
This ABG value reflects the respiratory component of acid base and is balanced by the lungs…
What is Carbon Dioxide (PaCO2).
**rationale**
PaCO2 tells us how well the lungs are removing CO2 from the body
Why are ABGs relevant to us as nurses?
What is they can detect life-threatening problems, guide interventions, monitor critically ill patients, and evaluate the bodies ability to compensate itself.
(Bernardo, 2024)
This ABG component is balanced by the kidneys would tell us if a person is in an Alkalotic state; also state the value..
What is HIGH pH, above 7.45
(Pruitt, 2024)
This ABG component is balanced by the kidneys and would tell us if a person is in an Acidotic state; also state the value..
What is LOW pH, less than 7.35
(Pruitt, 2024)
This is the normal range of HCO3 (Bicarbonate)..
What is 22-26
**memory tool**
BI (2 letters) CARBON (6 letters) =22-26
(Pruitt, 2024)
This is the normal range for PaCO2..
What is 35-45
**memory tool**
Pa similar to Na (sodium); Pa 35-45 = Na 135-145
(Pruitt, 2024)
Name a few scenarios (medical issues) that would indicate the drawing of ABGs..
What is COPD, DKA, Kidney failure, drug overdose, cardiac arrest, sepsis, severe vomitting/diarrhea, abnormal vital signs…
(Castro et al., 2024)
When Alkalosis (high pH) occurs, the body attempts to restore balance by retaining __ in the lungs and excreting __ in the kidneys.
HINT: how the body compensates itself to regain homeostasis
What is retaining carbon dioxide (CO2) in the lungs and excreting Bicarbonate (HCO3) in the kidneys.
(Castro et al., 2024)
When Acidosis (low pH) occurs, the body attempts to restore balance by removing ___ from the lungs and reabsorbing more ___ in the kidneys
HINT: how the body compensates itself to regain homeostasis
What is Carbon dioxide (CO2) from the lungs and Bicarbonate (HCO3) in the kidneys.
(Castro et al., 2024)
If HCO3 is out of range it means the ABG is ____ Alkalosis or Acidosis..
What is Metabolic.
**memory tool**
An easy way to interpret if an ABG is Metabolic vs. Respiratory is looking at the HCO3… if it’s outside the normal range, it’s metabolic!
If PaCO2 is out of range it means the ABG is ____ Alkalosis or Acidosis..
What is Respiratory.
**memory tool**
An easy way to interpret if an ABG is Metabolic vs. Respiratory is looking at the PaCO2… if it’s outside the normal range, it’s respiratory!
What is the method/procedure for obtaining an ABG?
What is an aseptic/clean procedure that requires blood draw from an ARTERY. Steps:
-Verify order & gather supplies
-Perform Allen test to check for good collateral blood flow
-Locate the artery, typically the radial
-Clean site & stick Pateint at a 30-45 degree angle
-Allow blood to fill the syringe (1-3ml)
-Remove needle and IMMEADIATELY apply pressure at the site for 5 min
-Send specimen to lab and document procedure
These bodily functions can cause the loss of large amounts of acid, causing the body to become alkalotic..
HINT: blowing off too much CO2, excreting of acid through bodily fluids
What is vomiting/NG suctioning, hyperventilation (anxiety/panic attacks), Diuretic use.
(Bernardo, 2024)
**Memory Tool**
“Blow fast, lose gas”
CO2 acts as an acid in the body to help maintain homeostasis, losing this acid causes pH levels to rise; loss of acid = alkalosis
These bodily functions can cause the build up of large amounts of acid, causing the body to become acidotic..
HINT: retaining of CO2, excess ___ acid, loose stools, ___ failure
What is hypoventilation (COPD, airway obstruction), lactic acid, diarrhea, kidney failure.
(Bernardo, 2024)
High HCO3 indicates metabolic ___ …
What is Metabolic alkalosis.
**memory tool**
“Bicarb is base. When Bicarb goes up, Alkalinity goes up” (like alka seltzer fizzes UP)
High PaCO2 indicates respiratory ___..
What is Acidosis.
**remember!! This is OPPOSITE of the metabolic ranges!! High vs. Low**
References
Bernardo, M. (2024). Analysing arterial blood gas results using the RoMe technique. Nursing Standard, 39(3), 40–43.
Castro, D., Patil, S. M., Zubair, M., & Keenaghan, M. (2024). Arterial blood gas. In StatPearls. StatPearls Publishing.
Pruitt, B. (2024). Strategies for interpreting arterial blood gases. Nursing, 54(1), 16–21.
These are some of the neurological symptoms of alkalosis that can occur when the acidity drops in the blood and the CNS experiences overexcitability..
What is muscle twitching, peripheral tingling, muscle cramping, lightheadedness
(Bernardo, 2024)
**rationale**
Alkalosis affects calcium balance, causing nerves to fire more easily (overexcitability)
**memory tool**
“Alka seltzer fizzes UP because it’s excited”
These are some of the neurological symptoms of acidosis that can occur when the acidity rises in the blood and the CNS becomes depressed..
What is confusion, lethargy, headache, decreased LOC, and coma (overall altered mental statu…
(Bernardo, 2024)
**Rationale**
Acid in the blood reduces neuronal excitability and brain function, causing CNS depression
Low HCO3 indicates metabolic ___ ..
What is acidosis.
Low HCO3 indicates respiratory ___…
What is Alkalosis.