Metabolic Alkalosis in Pediatrics

Metabolic Alkalosis in Pediatrics

Metabolic Alkalosis is a condition when there is bicarbonate retention and hydrogen ion loss. It is a clinical state characterized by high pH (decreased H+ concentration) and a high bicarbonate concentration in the plasma.  Usually, this occurs to children having prolonged vomiting, have ingested large amounts of bicarbonate antacids, had massive blood transfusions and nasogastric fluid loss (loss of hydrogen and chloride ions). Children who experience metabolic alkalosis appears to be weak, dizzy and would typically experience muscle cramps.

Causes

The following conditions are some of the predispoding factors of how children may be able to have metabolic alkalosis:

  • Decrease in body acids
  • Chronic ingestion of milk and calcium carbonate
  • Increase in bicarbonates
  • Prolonged nasogatric suctioning
  • Use of diuretics/diuretic therapy (thiazide, furosemide – promotes excretion of potassium)
  • Hypokalemiaa
  • Over consumption or use of antacids
  • Pyloric stenosis (gastric fluid loss)
  • Excessive adenosorticoid hormones (hyperaldosteronism, Cushing’s syndrome)
  • Cystic fibrosis

Manifestations

Children with metabolic alkalosis may manifest the following signs and symptoms:

  • Tingling of the fingers
  • Hypertonic muscles / muscle cramps
  • Depressed respiratory functions
  • Dizziness
  • Slow respirations
  • Shallow respirations
  • Disorientation
  • Hypokalemia
  • Ventricular disturbances
  • Decreased gastric motility
  • Seizures
  • Tremors
  • Muscle twitching
  • Atrial tachycardia
  • Paralytic ileus
  • Premature ventricular contractions
  • U- waves on the ECG

Assessment and Diagnosis

The following assessment and diagnostic tools will confirm the presence of metabolic alkalosis:

  • Arterial blood gas studies
    • Will reveal a pH greater than 7.45
    • Will reveal a bicarbonate concentration greater than 26 mEq/L
    • PaCO2 increase is evident – the lungs compensates for the excess bicarbonate levels by retaining CO2
    • Presence of hypokalemia
    • Urine chloride concentration
    • As a result of hypoventilation, hypoxemia occurs

Management

  • Just like any other imbalances, the treatment is aimed and focused on reversing the disorder.
  • Children with metabolic alkalosis are given adequate chloride to support the kidneys (absorbs sodium with chloride which allows the excretion of excess bicarbonates in the body).
  • For metabolic alkalosis caused by gastric suctioning, Histamine – 2 receptor antagonists are given as ordered, this drug reduces the production of gastric HCl, thus decreasing the alkalosis.
  • The body’s fluid volume should also be stabilized and restored. By administering sodium chloride fluids, alkalosis is prevented (prolonged volume depletion causes alkalosis).
  • For children with heart failure which could not tolerate rapid volume expansion, carbonic anhydrase inhibitors are used to treat the alkalosis.
  • In hypokalemic patients, KCl is indicated to replace both the lost potassium and chloride in the body.
  • Monitoring the child’s input and output is significantly helpful to manage alkalosis.

 

 

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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