Are you studying metabolic acidosis and need to know a mnemonic on how to remember the causes? This article will give you a clever mnemonic and simplify the signs and symptoms and nursing interventions on how to remember metabolic acidosis for nursing lecture exams and NCLEX.
In addition, you will learn how to differentiate metabolic acidosis from metabolic alkalosis. Don’t forget to take the metabolic acidosis and metabolic alkalosis quiz.
This article will cover:
- Metabolic acidosis simplified
- Lab values expected with metabolic acidosis
- Causes of metabolic acidosis
- Signs and symptoms of metabolic acidosis
- Nursing interventions for metabolic acidosis
Lecture on Metabolic Acidosis
Metabolic Acidosis
Metabolic Acidosis in Simple Terms: a metabolic problem due to the buildup of acid in the body fluids which affects the bicarbonate (HCO3 levels) either from:
- increased acid production (ex: DKA where ketones (acids) increase in the body which decreases bicarbonate)
- decreased acid excretion (ex: renal failure where there is high amount of waste left in the body which causes the acids to increase and bicarb can’t control imbalance)
- loss of too much bicarb (diarrhea)
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When this acidic phenomena is taking place in the body other systems will try to compensate to increase the bicarb back to normal. One system that tries to compensate is the respiratory system.
In order to compensate, the respiratory system will cause the body to hyperventilate by increasing breathing through Kussmaul’s respirations. Kussmaul respirations are deep, rapid breathes. The body hopes this will help expel CO2 (an acid) which will “hopefully” increase the pH back to normal.
Lab values expected in Metabolic Acidosis:
- HCO3: decreased <22
- Blood pH: decreased <7.35
- CO2: <35 or normal (may be normal but if it is decreased this is the body’s way of trying to compensate). **Remember the respiratory system is causing hyperventilation. The respiratory system tries to increase the pH from its acidotic states through tachypnea with Kussmaul’s breathing. The goal is to “blow off” the CO2 which is acidic to help alleviate the already acidotic conditions in the body.
Memorize these normal values for ABGs:
- pH 7.35-7.45
- PaCO2 35-45
- HCO3 22-26
Causes of Metabolic Acidosis
ACIDS
Accumlation of lactate leading to lactic acidosis (sepsis, shock)
Chronic diarrhea*
Impaired renal function*
Diabetic Ketoacidosis (DKA): high ketones
Salicylates toxicity
*most common causes
Signs & Symptoms of Metabolic Acidosis
- Main signs: Kussmaul’s respiration: very deep, fast breathing (body’s way of trying to compensate by exhaling the excessive CO2…in hopes of increasing bicarb and blood pH)
- Confused, weak, flushing, low blood pressure, cardiac changes (hyperkalemia)
Nursing Interventions for Metabolic Acidosis
Goal is to find the reason for the acidosis and correct it. Interventions will vary depending on the cause:
- Monitor respiratory system
- Assess other electrolyte levels:
- Potassium: hyperkalemia can occur (monitor for ECG changes like tall t-waves)
- however when it resolves there can be an extracellular to intracellular shift of K+ back into the cell which will causes hypokalemia, especially with DKA treatment
- Potassium: hyperkalemia can occur (monitor for ECG changes like tall t-waves)
- Monitor neuro status, safety, and place in seizure precautions
- IV fluids per doctor’s order:
- Sodium bicarbonate, 0.9% Sodium Chloride (isotonic)
- Dialysis may be needed if the patient is experiencing acidosis due to renal failure
- Diabetic ketoacidosis: IV fluids and insulin administration
- monitor for hypokalemia because insulin moves potassium inside the cell