Hypermagnesemia may be associated with neonatal hypotonia.
Patient selection: neonate with hypotonia
Situations where encountered:
(1) treatment of maternal eclampsia with magnesium sulfate
(2) use of magnesium antacids in the newborn
(3) impaired renal excretion of magnesium
Clinical features:
(1) encephalopathy
(2) hypotonia with depressed deep tendon reflexes
(3) ileus, causing abdominal distention and feeding difficulties
(4) bradycardia
(5) mild respiratory distress
Measuring the serum magnesium concentration usually identifies the hypermagnesemia.
The clinical findings improve once the magnesium levels have returned to normal.
