Medical Emergencies · patient case question
Does Patient A's uninvestigated heart murmur require antibiotic prophylaxis before extraction?
Patient case: A murmur, a virus and a bottle of hand sanitizer
Patient: Two patients and a practice question
Chief Complaint: A: “I need this broken tooth out.” B: attends with his sister, who has questions.
Background: A, 52-year-old male: a heart murmur was noted years ago at a routine physical and never investigated further. No prosthetic valve, no previous endocarditis, no congenital heart disease, no transplant. B, 38-year-old male: HIV positive, on antiretroviral therapy, viral load undetectable, CD4 610. His sister asks whether it is safe for the family to share utensils with him.
Vital Signs: A: BP 126/78 mmHg · HR 74 bpm
Findings: A: tooth #31 non-restorable. Alcohol-based hand rub is in use throughout the practice.
Show answer and explanation
Correct answer: B. No — a murmur alone is not an indication
- A. The timing or character of a murmur does not determine the need for prophylaxis. The underlying cardiac diagnosis does.
- B. CORRECT. The 2021 AHA list is short and specific: a PROSTHETIC VALVE or prosthetic material used in valve repair; PREVIOUS INFECTIVE ENDOCARDITIS; UNREPAIRED CYANOTIC congenital heart disease, or repaired disease with a residual defect adjacent to the patch or device, or within six months of repair; and CARDIAC TRANSPLANT recipients who develop valvulopathy. A MURMUR is a physical sign, not a diagnosis — most are innocent or functional, and even most pathological murmurs, including mitral valve prolapse, bicuspid aortic valve and rheumatic valve disease, were REMOVED from the prophylaxis list in the 2007 revision. What the murmur does warrant is medical evaluation to establish its cause, which may itself reveal an indication.
- C. Clindamycin was REMOVED from the AHA regimen in 2021 because of Clostridioides difficile risk, so it would be the wrong drug even where an indication existed.
- D. Amoxicillin 2 g one hour before the procedure is the correct REGIMEN, but this patient has no qualifying indication for it.
Note: The other half of the rule is the PROCEDURE. Even in a patient who qualifies, prophylaxis is required only for procedures involving manipulation of gingival tissue, the periapical region of teeth, or perforation of the oral mucosa. It is not required for routine anaesthetic injection through non-infected tissue, radiographs, orthodontic appliance placement, or the shedding of primary teeth.
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