In a patient Tetany like spasm is seen. Which are caused by due to imbalance of which electrolyte?

Appeared in: NORCET 3 - 2022 (Shift-2)

Explanation

Hypocalcemia, a serum calcium level below 9.0 mg/dL, is the primary cause of tetany.
Low calcium levels increase the excitability of nerve cell membranes by increasing sodium permeability.
This heightened neuromuscular excitability leads to spontaneous and involuntary muscle contractions, known as tetany.
Classic signs include carpopedal spasms, tingling around the mouth and extremities, and positive Chvostek's and Trousseau's signs.

Option A: Hypokalemia (low potassium) leads to decreased neuromuscular excitability, causing muscle weakness, flaccid paralysis, and cardiac dysrhythmias, not the hyper-excitability seen in tetany.
Option C: Hypercalcemia (high calcium) has the opposite effect of hypocalcemia; it decreases neuromuscular excitability.
Option D: Hyponatremia (low sodium) primarily affects the central nervous system by causing cerebral edema, leading to symptoms like confusion, headache, and seizures. Tetany is not a characteristic sign.

Visual 1: Diagram: Illustration of Trousseau's sign, showing the characteristic carpal spasm after inflating a blood pressure cuff.
Visual 2: Diagram: Illustration of Chvostek's sign, showing the location for tapping the facial nerve and the resulting facial muscle twitch.

Clinical Relevance

Nursing practice connection: Use the key finding related to Electrolyte Imbalances and Neuromuscular Manifestations to guide bedside assessment, documentation, and the next nursing action.
Nurses must be able to recognize the signs of hypocalcemia (tetany, Chvostek's, Trousseau's) promptly, as it can lead to life-threatening complications like laryngospasm and seizures.
Immediate nursing priorities include ensuring patient safety by implementing seizure precautions and maintaining a patent airway.
When administering IV calcium, the nurse must infuse it slowly and monitor the patient's cardiac rhythm and IV site closely to prevent complications like cardiac arrest or tissue damage.

How to Approach the Question

First, identify the key clinical sign presented in the question stem, which is 'Tetany like spasm'.
Recall the major functions of common electrolytes (Calcium, Potassium, Sodium, Magnesium) and their effect on neuromuscular function.
Specifically, remember that calcium stabilizes nerve membranes. Therefore, a lack of calcium (hypocalcemia) would lead to instability and hyper-excitability.
Correlate hyper-excitability with the symptom of tetany (involuntary muscle spasms).
Eliminate the other options by recalling their primary manifestations: Hypokalemia causes weakness, Hypercalcemia causes lethargy, and Hyponatremia causes CNS changes.

Concept Tested & Keywords

Q1AKBqq6MVWrleD0RczaRb

Practise the full NORCET 3 - 2022 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.