Why does pyloric stenosis cause hyponatremia?

This prolonged vomiting causes progressive loss of fluids rich in hydrochloric acid, which causes the kidneys to retain hydrogen ions in favor of potassium. The dehydration may result in hypernatremia or hyponatremia and may result in prerenal renal failure.

What is the key associated symptom for pyloric stenosis?

Signs include: Vomiting after feeding. The baby may vomit forcefully, ejecting breast milk or formula up to several feet away (projectile vomiting). Vomiting might be mild at first and gradually become more severe as the pylorus opening narrows.

How does pyloric stenosis correct metabolic alkalosis?

Purpose: Pyloromyotomy has been the treatment of choice for hypertrophic pyloric stenosis (HPS) for the past century. In most HPS cases, there is mild metabolic alkalosis, which requires intravenous fluid resuscitation with 5% dextrose/normal saline for 1-2 days.

Why is bicarbonate elevated in pyloric stenosis?

This pathophysiology is understood, considering that emesis results in hydrogen and chloride ion losses. The pancreas will secrete bicarbonate when stimulated by hydrogen reaching the duodenum but without this stimulus, there results an increase in serum bicarbonate and subsequent alkalosis.

Why is potassium low in pyloric stenosis?

ELECTROLYTE ABNORMALITIES Pyloric stenosis usually results in metabolic alkalosis with associated hypochloremia and hypokalemia due to a loss of hydrogen and chloride ions from vomiting gastric contents.

Why is there hypokalemia in gastric outlet obstruction?

Prolonged vomiting causes loss of hydrochloric acid and produces an increase of bicarbonate in the plasma to compensate for the lost chloride and sodium. The result is a hypokalemic hypochloremic metabolic alkalosis.

Why does pyloric stenosis cause metabolic alkalosis?

How do you diagnose pyloric stenosis?

Diagnosis of Pyloric Stenosis Blood tests – done to evaluate dehydration and mineral imbalances. Abdominal ultrasound — the gold standard for diagnosing pyloric stenosis. This is an imaging technique that uses high frequency sound waves and a computer to create images of blood vessels, tissues, and organs.

What is Hyperchloremic acidosis?

Hyperchloremic acidosis is a disease state where acidosis (pH less than 7.35) develops with an increase in ionic chloride. Understanding the physiological pH buffering system is important. The major pH buffer system in the human body is the bicarbonate/carbon dioxide (HCO3/CO2) chemical equilibrium system.[1][2][3]

Why is urine acidic in pyloric stenosis?

INFANTS WITH PYLORIC STENOSIS The excess loss of Cl depletes extracellular chloride and with the luminal loss of Hydrogen ions produces a metabolic alkalosis. The kidney tries to initially maintain blood pH by excreting an alkaline urine.

What is hypochloremic metabolic alkalosis?

Hypochloremic alkalosis results from either low chloride intake or excessive chloride wasting. Whereas low chloride intake is very uncommon, excessive chloride wasting often occurs in hospitalized children, usually as a result of diuretic therapy or nasogastric tube suctioning.

What electrolyte imbalance occurs in gastric outlet obstruction?

The classic electrolyte disorder of patients with long-standing gastric outlet obstruction is a hypochloremic, hypokalemic metabolic alkalosis.