Hypophosphatemia

A hypophosphatemia is defined as a serum phosphate level < 0.77 mmol/l, subject to the reference laboratory standards.

Clinical Presentation

Weakness, lethargy, decreased contractility of respiratory muscles, rhabdomyolysis, cardiac depression, encephalopathy, dysphagia, ileus, hemolysis, thrombocytopenia, impaired leukocyte and platelet functions.

It is common in intensive care units, where it is generally multifactorial.

Etiologies

Mainly due to redistribution: sepsis, correction of malnutrition, respiratory alkalosis, glucose infusions, correction of diabetic ketoacidosis. Other causes include urinary phosphate losses, Fanconi's renal syndrome, glycosuria, etc.

Therapeutic Management - Treatments

Systematic correction with potassium phosphate supplements KHPO4 20-80 mEq/day (e.g., 30 mEq over 2 hours followed by 30 mEq over 24 hours).

Etiological treatment when applicable.

Bibliography

EMC, Traité de néphrologie, Elsevier, 2018

Longo DL et al., Harrison - Principes de médecine interne, 18e éd., Lavoisier, 2013