Which of the following symptoms should be watched for a patient receiving a loop diuretic?

RRB Nsg. Superintendent-20 July 2019 (Shift-1)

Pharmacology

Medium

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-1)

Explanation

Loop diuretics (e.g., furosemide) are potent diuretics that cause significant excretion of potassium from the body, leading to hypokalemia (low serum potassium).
Potassium is essential for maintaining normal cardiac electrical activity and muscle contraction.
Low potassium levels disrupt the heart's electrical stability and weaken muscle function, which clinically manifests as cardiac arrhythmias and a weak, irregular pulse.

Option A: Loop diuretics decrease the body's total fluid volume, which leads to a reduction in blood pressure (hypotension), not an increase.
Option C: These are non-specific neurological symptoms. While severe electrolyte imbalances like hyponatremia (also a risk with diuretics) can cause confusion, the most direct and life-threatening effect of potassium loss is on the heart.
Option D: Paresthesias (numbness and tingling) are a classic symptom of hyperkalemia (high potassium), which is the opposite of the effect caused by loop diuretics.

Visual 1: Diagram: The Nephron. A diagram showing the different segments of the renal tubule, highlighting the Loop of Henle, which is the primary site of action for loop diuretics.
Visual 2: ECG Strip: Hypokalemia. An image comparing a normal ECG waveform to one showing the characteristic changes of hypokalemia, such as flattened T-waves and the presence of a U-wave.

Clinical Relevance

Nursing practice connection: Use the key finding related to Adverse effects of loop diuretics to guide bedside assessment, documentation, and the next nursing action.
The nurse's priority when caring for a patient on a loop diuretic is to monitor for signs of hypokalemia and hypotension. This includes regularly checking vital signs (especially pulse and blood pressure), assessing for muscle weakness, and reviewing serum potassium lab results.
Severe hypokalemia (potassium less than 2.5 mEq/L) is a medical emergency that can lead to life-threatening cardiac arrest. Prompt recognition and reporting of an irregular pulse are critical for patient safety.
What if the patient was taking a potassium-sparing diuretic like spironolactone instead? The nurse's priority would shift to monitoring for signs of hyperkalemia, with key symptoms being paresthesias, muscle weakness, and peaked T-waves on an ECG.

How to Approach the Question

First, identify the core subject of the question, which is the side effects of a 'loop diuretic'.
Recall the primary mechanism of loop diuretics. They cause significant fluid and electrolyte loss, most notably potassium.
Connect the primary side effect, potassium loss (hypokalemia), to its physiological consequences.
Evaluate each option based on the effects of hypokalemia. A weak, irregular pulse is a direct result of hypokalemia's impact on cardiac muscle and electrical conduction.
Systematically eliminate the other options. Loop diuretics cause hypotension (not hypertension). Restlessness is non-specific. Paresthesias are a sign of the opposite condition, hyperkalemia.
Conclude that the most specific and critical symptom to monitor for is the weak, irregular pulse.

Concept Tested & Keywords

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