A client is brought to the emergency department reporting chest pain. Assessment shows vital signs that include a blood pressure (BP) of 155/88 mm Hg, pulse 88 beats per minute (BPM), and respirations 20 breaths per minute. The nurse administers nitroglycerin 0.4 mg sublingually. The treatment is found to be effective when the reassessment of vital signs shows which data?

1. A

   BP 160/70 mm Hg, Pulse-98 BPM, RR-20 breaths per minute

2. B

   BP 90/60 mm Hg, Pulse-48 BPM, RR-24 breaths per minute

3. C

   BP 170/82 mm Hg, Pulse-60 BPM, RR-24 breaths per minute

4. D

   BP 88/56 mm Hg, Pulse-92 BPM, RR-20 breaths per minute

Appeared in: NORCET -4 , 2023

Explanation

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• Nitroglycerin is a vasodilator, meaning it widens blood vessels. This action is its primary mechanism for relieving chest pain by reducing the heart's workload.
• Widening the veins (venodilation) decreases the amount of blood returning to the heart (preload). Widening the arteries (arterial dilation) reduces the pressure the heart has to pump against (afterload).
• Both preload and afterload reduction cause a decrease in blood pressure. The initial BP of 155/88 mm Hg dropping to 88/56 mm Hg is a clear indicator of this effect.
• As a compensatory response to the sudden drop in blood pressure, the body's baroreceptors trigger the heart to beat faster to maintain adequate blood flow to vital organs. This is called reflex tachycardia.
• The pulse increasing from 88 BPM to 92 BPM demonstrates this expected compensatory reflex tachycardia.
• Therefore, the combination of significantly decreased blood pressure and a slightly increased pulse rate confirms the medication is working as intended.

Why Other Options Were Wrong

• Option B: This option shows an increase in systolic blood pressure (from 155 to 160 mm Hg). Nitroglycerin's primary effect is vasodilation, which should lower, not raise, blood pressure.
• Option C: Although the blood pressure has decreased, the heart rate has also dropped significantly to 48 BPM (bradycardia). The expected compensatory response to nitroglycerin-induced hypotension is reflex tachycardia (increased heart rate), not bradycardia.
• Option D: This option shows a significant increase in systolic blood pressure (from 155 to 170 mm Hg), which is the opposite of nitroglycerin's vasodilatory effect.

Related Visual

• Visual 1: Flowchart: Illustrating the mechanism of action of nitroglycerin. Start with 'Nitroglycerin Administration' -> 'Release of Nitric Oxide' -> 'Smooth Muscle Relaxation (Vasodilation)' -> 'Decreased Preload & Afterload' -> 'Decreased Myocardial O2 Demand' & 'Decreased Blood Pressure'. A side branch from 'Decreased Blood Pressure' leads to 'Baroreceptor Stimulation' -> 'Reflex Tachycardia'.

Clinical Relevance

• Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Pharmacological effects of nitroglycerin and its impact on vital signs in acute care settings.
• A key nursing responsibility is to monitor vital signs before and after administering nitroglycerin to assess for therapeutic effects (pain relief, decreased BP) and adverse effects (severe hypotension, headache, reflex tachycardia).
• If a patient's systolic BP is below 90 mm Hg, the nurse should hold the dose and notify the provider, as further vasodilation could lead to dangerous hypotension and inadequate organ perfusion.
• Patients should be instructed to sit or lie down before taking sublingual nitroglycerin to prevent falls or injury from potential dizziness or syncope caused by orthostatic hypotension.

How to Approach the Question

• First, identify the core of the question: What are the expected vital sign changes after giving nitroglycerin?
• Recall the primary pharmacological action of nitroglycerin. It is a vasodilator.
• Determine how vasodilation affects blood pressure. Widening blood vessels lowers resistance, so blood pressure should decrease.
• Consider the body's compensatory mechanisms. When blood pressure drops, the heart rate typically increases to compensate (reflex tachycardia).
• Evaluate each option against this expected pattern: decreased BP and increased pulse.
• Option A (BP 88/56, Pulse 92) matches this pattern. The other options show increased BP or decreased pulse, which are inconsistent with the expected response.

Concept Tested & Keywords

• Concept Tested: Pharmacological effects of nitroglycerin and its impact on vital signs.
• Stem keywords: chest pain, nitroglycerin, vital signs, blood pressure, pulse
• Lead-in keywords: effective
• Clinical cues: Initial BP of 155/88 mm Hg and pulse of 88 BPM provide the baseline to evaluate the drug's effect.

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Q6R4vHSfyMEuFqccljJqR1

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