Are you studying metabolic alkalosis 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 alkalosis for nursing lecture exams and NCLEX.
In addition, you will learn how to differentiate metabolic alkalosis from metabolic acidosis. Don’t forget to take the metabolic acidosis and metabolic alkalosis quiz.
This article will cover:
- Metabolic alkalosis simplified
- Lab values expected with metabolic alkalosis
- Causes of metabolic alkalosis
- Signs and symptoms of metabolic alkalosis
- Nursing interventions for metabolic alkalosis
Lecture on Metabolic Alkalosis
Metabolic Alkalosis
Metabolic alkalosis in simple terms: a metabolic problem caused by the excessive loss of acids (H+) or increased amount of bicarb (HCO3) produced in the body that leads to an alkalotic state in the body. Disease processes and drugs can cause metabolic alkalosis.
When metabolic alkalosis happens in the body other systems try to compensate by hopefully fixing the blood’s pH and bicarb level. One system that does this is the respiratory system by stimulating the respiratory system to hypoventilate (decrease respirations) which will retain PaCO2 (carbon dioxide) so it will decrease the pH back to normal, hence you will start to see bradypnea in your patient.
If a patient is experiencing metabolic alkalosis they will present with the following labs:
- HCO3: increases >26
- Blood pH: increases >7.45
- CO2: >45 or normal (may be normal but if increased this is the body’s way of trying to compensate. Remember the respiratory system tries to decrease the pH from its alkalotic state by causing hypoventilation ( bradypnea). The respiratory system hopes that if the CO2 increases enough it will cause the pH to decrease and the kidneys will start to excrete the bicarb which will hopefully decrease the overall HCO3.
Remember what normal values are:
- pH 7.35-7.45
- PaCO2 35-45
- HCO3 22-26
Causes of Metabolic Alkalosis
Remember: “Alkali”
- Acid loss via stomach due nasogastric suction or vomiting
Low chloride level which increases the bicarb level
K+ loss (hypokalemia): this state causes wasting of chloride and increases reabsorption of bicarb
Aldosterone elevated (hyperaldosteronism): causes the renal tubule in the kidneys to keep sodium which wastes hydrogen ions (ex: potassium) and this causes you to keep bicarb (HCO3)
Loop & thiazide: causes the kidneys to waste hydrogen ions and chloride through the urine which in turn increases the bicarb
Increased sodium bicarb administration (trying to correct metabolic acidosis)
Signs and Symptoms of Metabolic alkalosis
- Bradypnea (hypoventilation) <12 bpm and respiratory failure
- Many symptoms due to low potassium (dysrhythmia), tetany, tremors, muscle weakness/cramping, tired, irritable
Nursing Interventions for Metabolic Alkalosis
- Treatment is based on: Finding the cause and correcting it!
- Monitor ECG (at risk for dysrhythmias), respiratory status (risk for respiratory failure) and neuro status.
- Monitor electrolytes: low potassium and chloride
- Administer replacement per doctor’s orders
- If vomiting give antiemetics to decrease loss of acids through emesis
- Hold diuretics that worsen alkalosis (loop and thiazides)
- Doctor may order Acetazolamide (Diamox): this is a carbonic anhydrase inhibitor and a diuretic which reduces the reabsorption of bicarb