An elderly client is admitted with elevated magnesium level related to a history of renal insufficiency and excess use of antacids and laxatives containing magnesium

Question

On admission assessment, the nurse notes which clinical manifestations that correlate to hypermagnesemia? Select all that apply.
A) Hyporeflexia
B) Blood pressure 180/90
C) Tetanic muscle contractions
D) Muscle weakness causing shallow breathing
E) Paresthesia of the lips

Answer 1

Ans: A, D
Feedback:
The signs and symptoms occur only when serum magnesium levels exceed 4.0 mg/dL. Hypermagnesemia affects neuromuscular and cardiovascular function. Increased levels of magnesium cause hyporeflexia and muscle weakness. Blood pressure is decreased, and the ECG shows an increase in the PR interval, a shortening of the QT interval, T-wave abnormalities, and prolongation of the QRS and PR intervals. Severe hypermagnesemia is associated with muscle and respiratory paralysis, complete heart block, and cardiac arrest. Signs of magnesium deficiency are not usually apparent until the serum magnesium is less than 1.0 mEq/L. Hypomagnesemia is characterized by an increase in neuromuscular excitability as evidenced by hyperactive deep tendon reflexes, paresthesias (i.e., numbness, pricking, tingling sensation), muscle fasciculations, and tetanic muscle contractions.