Hyperkalemia in a neonate can result in hypotonia.
Mechanism: prolongation of the repolarization phases
Risk factors for hyperkalemia in the neonate include:
(1) decreased excretion of potassium by the kidney
(2) maternal magnesium therapy with hypermagnesemia
(3) acute hemolysis
Clinical findings:
(1) muscular paralysis with weakness
(2) ileus with hypoactive bowel sounds
(3) respiratory paralysis
Additional findings:
(1) abnormal ECG (peaked T waves, decrease R wave amplitude, wide QRS complex, prolonged PR interval)
(2) elevated serum potassium (without specimen hemolysis)
The hypotonia is reversible after the hyperkalemia is corrected.
