Medical Emergencies · single question
A pregnant patient in her third trimester starts feeling dizzy and lightheaded during treatment. What is the most likely cause?
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Correct answer: A. Pressure on the inferior vena cava and aorta (aortocaval compression)
- A. In the third trimester, the gravid uterus compresses the inferior vena cava and aorta when the patient is supine. This reduces venous return, causing hypotension and dizziness. Treatment: immediately tilt the patient to the LEFT lateral decubitus position.
- B. This is close but the specific mechanism is aortocaval compression, not just 'hypotension' generally.
- C. Hypoglycemia is possible in pregnancy but not specifically linked to the supine dental position — aortocaval compression is the classic third-trimester dental emergency.
- D. Labor would not cause sudden positional dizziness — it would present with contractions and pain.
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