Medical Emergencies · single question
When a patient gets up from the dental chair and experiences dizziness and lightheadedness, what is the most likely cause? (Patient has hypertension and takes Lisinopril)
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Correct answer: C. Orthostatic hypotension
Orthostatic (postural) hypotension is a drop in blood pressure ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing. ACE inhibitors (like lisinopril) cause vasodilation and can exacerbate orthostatic hypotension, especially when patients rise quickly from a supine position in the dental chair. Management: raise chair slowly, have patient sit for 1-2 minutes before standing, lower feet first.
- A. Incorrect. Hypoglycemia would cause other symptoms (confusion, diaphoresis, trembling) and is not specifically associated with position change.
- B. CORRECT. Orthostatic hypotension from ACE inhibitor (lisinopril) + sudden position change from supine in dental chair to upright causes postural blood pressure drop → dizziness/lightheadedness.
- C. Incorrect. True vasovagal syncope involves loss of consciousness — the patient has dizziness only, not unconsciousness. The position-change context points to orthostatic hypotension.
- D. Incorrect. Hypertensive crisis would cause severe headache, blurred vision, possibly chest pain — dizziness from chair rising is orthostatic, not hypertensive.
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