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Medical Emergencies · patient case with 3 questions

The medically complex patient in the chair

Scenario: Three management questions in patients with cardiovascular and metabolic disease.

Question 1

A hypertensive patient on lisinopril needs an extraction. After local anaesthesia the blood pressure reads 150/95. What would you do?

  1. No modification needed — proceed with treatment
  2. Administer an extra 10 mg of lisinopril
  3. Place the patient supine and administer oxygen by mask
  4. Cancel and refer for urgent hypertensive management
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Correct answer: A. No modification needed — proceed with treatment

  • A. Correct. 150/95 is a mild, transient elevation entirely consistent with anxiety and the anaesthetic injection. It is well below the threshold for deferring care, so treatment proceeds with routine monitoring.
  • B. A dentist does not dose a patient's antihypertensive. Adjusting prescribed medication is the physician's role, and an extra dose risks hypotension.
  • C. Oxygen and repositioning treat hypotension or syncope, not a mildly raised reading in a comfortable patient.
  • D. Urgent referral is reserved for readings around 180/110 or above, or for a patient with symptoms of end-organ damage.

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Question 2

What is the maximum dose of epinephrine for a patient with significant cardiac disease?

  1. 0.2 mg
  2. 0.1 mg
  3. 0.04 mg
  4. 0.5 mg
Show answer and explanation

Correct answer: C. 0.04 mg

  • A. 0.2 mg is the ceiling for a healthy ASA I–II patient, roughly eleven cartridges of 1:100,000.
  • B. 0.1 mg is not a recognised ceiling for either group.
  • C. Correct. The cardiac-risk ceiling is 0.04 mg — about two cartridges of 1:100,000 epinephrine, since each 1.8 mL cartridge contains roughly 0.018 mg.
  • D. 0.5 mg is the dose of epinephrine given intramuscularly for anaphylaxis, not a local anaesthetic limit.

Note: Cardiac-risk patients here means ASA III–IV: recent MI or stroke, unstable angina, uncontrolled arrhythmia, or uncontrolled hypertension.

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Question 3

A patient with gout takes allopurinol. What would you expect to find in the temporomandibular joint?

  1. Amyloid deposits
  2. Monosodium urate crystals
  3. Calcium pyrophosphate crystals
  4. Cholesterol clefts
Show answer and explanation

Correct answer: B. Monosodium urate crystals

  • A. Amyloid deposition affects joints only in dialysis-related amyloidosis, a rare and unrelated entity.
  • B. Correct. Gout is deposition of monosodium urate crystals in and around joints; allopurinol lowers uric acid production by inhibiting xanthine oxidase.
  • C. Calcium pyrophosphate crystals cause pseudogout (chondrocalcinosis), a different crystal arthropathy not treated with allopurinol.
  • D. Cholesterol clefts appear in odontogenic cysts and chronic inflammatory lesions, not in joints.

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