NBME Medicine Form 6 - Answers & Explanations

Author: Sagie Haziza & Gennadiy Guralnik

Editor: Jordan Abrams

1) Abnormal red blood cell membrane

• Hereditary spherocytosis: jaundice, anemia, high-normal MHCH, loss of central pallor

• ⊖ Direct Coombs rules out AIHA

• Cholecystectomy → chronic hemolysis → indirect bilirubin gallstones

2) Positive findings for anti-centromere antibody

• CREST syndrome: calcinosis cutis, Raynaud phenomenon, esophageal dysmotility,

sclerodactyly, telangiectasia

3) Syringomyelia

• Cystic cavity in spinal cord → block of anterior white commissure (spinothalamic tract) →

bilateral, cape-like loss of pain and temperature

• Fine touch sensation preserved

• Associated with Chiari 1 malformation

4) Ruptured papillary muscle

• Acute, usually within 3-5 days post MI

• Typically with RCA infarction (posteromedial papillary muscle)

• Clinical findings: Severe pulmonary edema, new holosystolic murmur

5) No further testing is indicated

• Normal BP (140/90)

• Hematocrit normal (42%)

• No RBC in urinalysis

• HR ↑ because of pain/SNS

6) Ambulatory ECG monitoring

• Indications: syncope, near syncope or dizziness occurring on a near daily basis

○ Palpitations

○ Afib for assessment of rate or rhythm control

○ Ectopic or premature atrial beats

7) Severity of hypoxemia

• COPD → ↑ shunting → ↑ hypoxic vasoconstriction → pulmonary hypertension (loud S2/P2,

prominent pulmonary arteries, JVD)

8) No further tests are indicated

• Preoperative cardiac assessment includes: ECG, echo and stress test

• Stress test is only indicated when the patient has poor functional capacity: breathless or

chest pain with activity

9) Jarisch-Herxheimer reaction

• Treatment for syphilis (or other spirochetes [eg, lyme disease, leptospirosis]) → toxin release from killed bacteria

• Clinical findings: acute onset fever, chills, myalgia

10) Metformin

• Diabetic patients with comorbid pneumonia have ↑ risk of lactic acidosis if taking

metformin

• Metformin is also contraindicated in patients with liver failure, renal failure or sepsis

11) Surgical excision of apocrine tissue

• Occlusion of follicular pilosebaceous unit → Hidradenitis suppurativa

• Commonly affects intertriginous skin areas (eg, axilla, groin)

• Treatment is early radical excision of affected area

12) Hydration

• Preventative measures for contrast induced kidney injury: peri-procedural saline

hydration, use lowest volume of contrast agent, hold NSAIDs

13) Acyclovir

• Acute (<1 week) fever, altered mental status, or focal neurological symptoms are consistent

with HSV meningitis

• Treatment: Acyclovir

14) Airway compromise

• Tonsillitis with massive edema may occlude airway

15) Intravenous administration of 0.9% saline

• Treatment for suspected variceal hemorrhage: place 2 large bore IV (volume resuscitation),

IV octreotide, Abx → Endoscopic therapy

16) 80%

• 80 positive infections on new stool test

• 100 positive infections on gold standard biopsy

• Sensitivity = 80/100

17) Washing the area of involvement

• After a needle stick injury, a patient with immunization to Hep B does not need vaccine/booster, but should sterilize the area

18) Inflammation caused by release of cytokine by effector and memory T lymphocytes

• Type 4 delayed hypersensitivity

19) Corticosteroids therapy

• ↓ platelets <30,000 or symptoms of ITP → treat with corticosteroids, IVIG or splenectomy if refractory

• Megakaryocytes seen on bone marrow aspiration

20) Chlamydia trachomatis

• Tender boggy prostate, WBCs on urinalysis, ⊖ culture in young patient

• Intracellular indicates chlamydia (vs. gonorrhea)

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21) Ulnar nerve compression

• Ulnar nerve (C8-T1) insult → hypothenar atrophy + interosseous muscle

dysfunction (ab/adduction of fingers [paper slipping from fingers])

22) Swallowing study

• Oropharyngeal dysphagia clinical presentation: Chronic cough after meals, mild dysarthria,

history of multi infarct dementia

• Dx: video fluoroscopic barium swallow

23) Iron

• Anemia with hypochromasia (central pallor) is consistent with iron deficiency anemia

• Not sideroblastic (no basophilic stippling seen)

• Not megaloblastic (no hyper-segmented neutrophils)

24) Serum protein electrophoresis

• Multiple myeloma: hypercalcemia, renal failure, anemia, bone lytic lesions

25) Subcutaneous administration of enoxaparin

• Evidence of DVT on ultrasound→ enoxaparin is the next best step

• Warfarin takes several days to work and is not the best treatment

26) Lisinopril

• ACEi → ↓ mortality in HFrEF (heart failure with reduced ejection fraction)

• Metoprolol and spironolactone would not work well in an acute setting because they could

↓ cardiac output (CO)