Nursing Fundamentals - Acid-Base Imbalance
They include respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis, classified according to whether the disturbance arises from respiratory (CO₂-related) or metabolic (HCO₃⁻‑related) mechanisms and whether it results in acidosis or alkalosis.
What are the 4 types of acid-base imbalances?
Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis
Key Terms
What are the 4 types of acid-base imbalances?
Respiratory acidosis
Respiratory alkalosis
Metabolic acidosis
Metabolic alkalosis
From what type of vessel is an acid-base gas sample (ABG) obtained?
Through a blood draw on an artery.
The radial artery is the most common.
What is the Allen test?
Test is done to make sure the radial artery has good blood circulation to the hand before getting a blood sample for an ABG.
What are the steps for doing an Allen test?
Apply pressure over ulnar and radial arteries at same time
Ask client to open and close hand a few times (hand should blanch/turn white)
<...What 3 lab values are used to determine an acid-base imbalance?
pH: indicates how acidic or alkaline the blood is.
CO2: indicates how much acid the client is holding onto or getting rid of through the lung...
What are the normal lab values for pH, CO2, and HCO3?
When are the abnormal values acidotic or alkalotic?
pH: (acidotic) ↓ 7.35 - 7.45 ↑ (alkalotic)
CO2: (alkalotic) ↓ 35 - 45 ↑ (acidotic)
HCO3: (acidotic) ↓ 22-26 ↑ (alkalotic)
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
What are the 4 types of acid-base imbalances? | Respiratory acidosis Respiratory alkalosis Metabolic acidosis Metabolic alkalosis |
From what type of vessel is an acid-base gas sample (ABG) obtained? | Through a blood draw on an artery. The radial artery is the most common. |
What is the Allen test? | Test is done to make sure the radial artery has good blood circulation to the hand before getting a blood sample for an ABG. |
What are the steps for doing an Allen test? | Apply pressure over ulnar and radial arteries at same time Ask client to open and close hand a few times (hand should blanch/turn white) Release ulnar (keep pressure on radial) Assess color of hand If hand doesn’t turn back to pink within 7 seconds, don’t use it |
What 3 lab values are used to determine an acid-base imbalance? | pH: indicates how acidic or alkaline the blood is. CO2: indicates how much acid the client is holding onto or getting rid of through the lungs. HCO3: indicates how much bicarbonate the client is holding onto or getting rid of through the kidneys. |
What are the normal lab values for pH, CO2, and HCO3? When are the abnormal values acidotic or alkalotic? | pH: (acidotic) ↓ 7.35 - 7.45 ↑ (alkalotic) CO2: (alkalotic) ↓ 35 - 45 ↑ (acidotic) HCO3: (acidotic) ↓ 22-26 ↑ (alkalotic) |
What are the steps to determine the type of acid-base imbalance? | Determine if the pH is acidic or alkalotic (that will determine if the overall imbalance is “acidosis” or “alkalosis”) Determine if both the CO2 and HCO3 is acidotic or alkalotic Determine if CO2 or HCO3 matches with pH If CO2 is the same as pH, then the imbalance is “Respiratory” If HCO3 is the same as pH, then the imbalance is “Metabolic” |
What is an uncompensated acid-base imbalance? | only one of the values is abnormal: CO2 or HCO3 and pH is abnormal |
What is a compensated acid-base imbalance? | If both CO2 and HCO3 are abnormal: partially compensated: pH is also abnormal fully compensated: pH is normal |
What is this acid-base imbalance? pH = 7.32 CO2 = 50 HCO3 = 24 | Respiratory Acidosis, uncompensated pH = 7.32 (acidosis) CO2 = 50 (acidosis) HCO3 = 24 (normal) |
What is this acid-base imbalance? pH = 7.50 CO2 = 32 HCO3 = 24 | Respiratory Alkalosis, uncompensated pH = 7.50 (alkalotic) CO2 = 32 (alkalotic) HCO3 = 24 (normal) |
What is this acid-base imbalance? pH = 7.30 CO2 = 40 HCO3 = 19 | Metabolic Acidosis, uncompensated pH = 7.30 (acidosis) CO2 = 40 (normal) HCO3 = 19 (acidosis) |
What is this acid-base imbalance? pH = 7.50 CO2 = 41 HCO3 = 28 | Metabolic Alkalosis, uncompensated pH = 7.50 (alkalosis) CO2 = 41 (normal) HCO3 = 28 (alkalosis) |
What is this acid-base imbalance? pH = 7.50 CO2 = 47 HCO3 = 28 | Metabolic Alkalosis, partially compensated pH = 7.50 (alkalosis) - abnormal CO2 = 47 (acidosis) - abnormal HCO3 = 28 (alkalosis) - abnormal Partially compensated is when both CO2 and HCO3 are both abnormal. pH is also abnormal. Only the CO2 compensated by going into an abnormal range, not the pH - so it was a partial compensation. |
What is this acid-base imbalance? pH = 7.36 CO2 = 50 HCO3 = 29 | Respiratory Acidosis, fully compensated pH = 7.36 - normal but closer to acidosis CO2 = 50 (acidosis) - abnormal HCO3 = 29 (alkalosis) - abnormal Fully compensated is when both CO2 and HCO3 are both abnormal. pH is normal but closer to either acidosis or alkalosis. The HCO3 compensated by going into the abnormal range, and then the pH compensated by going into the normal range - so it was a full compensation. |
What are the characteristic signs and symptoms of all acid-base imbalances, regardless of which type? (Immediate Complication) | Neuro symptoms: confusion and then coma Muscle symptoms: muscle weakness and dysrhythmias Most of the symptoms are caused by electrolyte imbalances. |
What is the main electrolyte imbalance for acidosis? | Acidosis = Hyperkalemia This is due to shifts in acid and electrolytes in the blood and cells. |
What is the main electrolyte imbalance for alkalosis? | Alkalosis = Hypokalemia and Hypocalcemia This is due to shifts in acid and electrolytes in the blood and cells. |
Why do lung diseases cause respiratory acidosis? | Lung diseases cause underventilation because the lungs are not able to expand. The client is unable to get rid of CO2 gas, causing acid build-up. |
Why do narcotics and opioids cause respiratory acidosis? | Narcotics and opioids cause underventilation because the medications suppress respirations. The client is unable to get rid of CO2 gas, causing acid build-up. |
Why does abdominal surgery cause respiratory acidosis? | Abdominal surgery can cause underventilation because the client is in pain and doesn’t want to breathe because it hurts. The client is unable to get rid of CO2 gas, causing acid build-up. |
What are the characteristic signs and symptoms for respiratory acidosis? | underventilation that can occur by decreased or increased respirations low O2 saturation level |
Why do hyperventilation or panic attacks cause respiratory alkalosis? | Breathing too fast causes the client to breathe out too much CO2 gas. |
Why do vomiting and gastrointestinal suction cause metabolic alkalosis? | There is acid in gastric secretions. When there is a loss of gastric secretions, the blood can become more alkalotic. |
Why does taking too many antacids cause metabolic alkalosis? | There is bicarbonate in antacids. Taking too many antacids makes the blood alkalotic. |
Why does diabetic ketone acidosis (DKA) cause metabolic acidosis? | DKA is when the blood sugar is very high. The body will use fat cells for energy instead. These fat cells breakdown into an acid called ketones. The ketones cause blood to be acidotic. |
Why does sepsis cause metabolic acidosis? | Sepsis is when there is an infection in the blood. Bacteria break down into acids, causing the blood to be acidotic. |
Why does diarrhea cause metabolic acidosis? | Diarrhea results in loss of base, causing the blood to become more acidic. |
Why does chronic kidney disease cause metabolic acidosis? | The kidneys are no longer working. They are unable to get rid of the acid in the blood. |
How are the acid-base imbalances treated? | Because there are many reasons for an acid-base imbalance, try to figure out the cause and treat that first. |
What is a quick-fix treatment for metabolic acidosis if the cause is not readily known? | Give sodium bicarbonate. |