Metabolic Acidosis in Pediatrics

Metabolic Acidosis in Pediatrics

Metabolic Acidosis is usually caused by a depletion of bicarbonate in the stool or either an increase in ketone bodies such as acetoacetic acid, acetone, or beta hydroxybutyric acis in the blood stream. It is a clinical alteration wherein a decrease in pH (increase in H+ concentration) and a low plasma bicarbonate concentration is exhibited. This malady is precipitated by vomiting, gastric suction, diarrhea or diabetic ketoacidosis.

Causes

Metabolic Acidosis occurs on variety of causes, but most frequently is predisposed by the following conditions:

  • Increased body acids (acetoacetic acid, acetone, or beta hydroxybutyric acis)
  • Decreased bicarbonates
  • Shock
  • Starvation
  • Increased acid intake
  • Alcohol ketoacidosis
  • Renal Failure
  • Diabetic ketoacidosis

Manifestations

A child with metabolic acidosis would usually present as lethargic, quite confused and is having increased pulses. However these manifestations may vary depending on the severity of the acidosis. The following lists the most common signs and symptoms:

  • Headache
  • Confusion
  • Drowsiness
  • Lethargy
  • Warm and dry skin (happens during severe acidosis)
  • Nausea
  • Vomiting
  • Peripheral vasodilation
  • Decreased cardiac output
  • Decreased blood pressure
  • Cold and clammy skin (happens during mild acidosis)
  • Tachycardia
  • Dysrhythmias
  • Shock
  • Increased and rapid respirations
  • Deep respirations

Assessment and Diagnostics

In order to diagnose metabolic acidosis, the following laboratories and diagnostic tools are used:

  • The principal indicator that indeed there is a metabolic acidosis is a decrease in bicarbonate level
  • Arterial Blood Gas measurements – diagnose and verifies acid imbalance (metabolic acidosis)
    • Bicarbonate level is low (less than 22 mEq/L)
    • pH level is low (less than 7.35)
    • Increase in potassium levels – a shift of potassium ions outside the cells
    • Decrease in potassium levels – a shift of potassium ions back to the cell after the acidosis is corrected
    • CO2 levels increased, therefore hyperventilation occurs, a compensatory mechanism to decrease the CO2 levels
    • Electrocardiogram (ECG) – detects dysrhythmias that is caused by increased potassium

Management

  • Management of metabolic acidosis in children is the same as with adults, that is correcting the metabolic defect.
  • Oxygen administration
  • Correct DKA with insulin or glucose
  • Vital signs monitoring
  • If too much consumption of chloride is the cause, then most probably the treatment will be focused on eliminating its source.
  • If the pH is less than 7.1 and the bicarbonate level is less than 10mEq/L, bicarbonate is administered as ordered.
  • Potassium levels are monitored closely and are corrected after the acidosis is intervened.
  • If the bicarbonate levels reached less than 12 mEq/L, alkalyzing agents are given as ordered.

Byron Webb Romero, RN, MSN

Finished BSN at Lyceum of the Philippines University, and Master of Science in Nursing Major in Adult Health Nursing at the University of the East Ramon Magsaysay Memorial Medical Center. Currently working at Manila Doctors College of Nursing as a Team Leader for Level I and II, Lecturer for Professional Nursing Subjects, and also a Clinical Instructor.

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