NBME Medicine Form 5 - Answers & Explanations

Updated: Mar 6, 2020

Editor: Jordan Abrams

1) Valvular insufficiency of deep veins

● Mild edema due to incompetent valves + varicose veins due to saphenous vein reflux + area of hyperpigmentation (stasis dermatitis) over left ankle

2) Not eating mahimahi

● Histamine toxicity (scombroid poisoning) symptoms resembling anaphylaxis: flushing, headache and light-headedness (may also see urticaria, itching)

● Symptoms generally present within 10 minutes of eating dark-meat fish (eg, mahimahi)

3) Antihypertensive therapy

● HTN is greatest risk factor for both ischemic and hemorrhagic stroke (~4x the risk of a CVA compared to a normotensive individual)

● HTN → ↑ shearing forces on vascular endothelium → exacerbated atherosclerosis

4) Toxic adenoma of thyroid gland

● Toxic thyroid adenoma (hyper-functioning thyroid nodule) → hyperthyroidism sxs (eg, weight loss, palpitations, heat intolerance, fatigue, tachycardia, etc.)

● Labs: ↓ TSH, ↑ free T3 & T4, ↑ radioactive iodine (RAI) uptake in a single nodule

● DDx: ○ Subacute (de Quervain) thyroiditis would have a tender/painful goiter

○ Graves disease would show ↑ RAI uptake in diffuse pattern

○ Toxic multinodular goiter would ↑ RAI uptake in multiple nodules

5) Penicillin

• Painless chancroid on glans of penis is characteristic of Syphillis

6) Pancreatic adenocarcinoma

● Pancreatic tumor can commonly compress and dilate pancreatic duct and common bile duct (double duct sign) → ↑ ALP and ↑ Direct Bilirubin

● Unexplained migratory thrombophlebitis can also commonly be seen in Pancreatic Adenocarcinoma

7) B-Thalassemia trait

● ↓ synthesis of Beta chains → ↑ HbA2 (2 alpha chains, 2 delta chains)

● Beta Thalassemia trait is most often asymptomatic in presentation

8) Tuberculosis

● Common Tuberculosis symptoms include fever, chills, hemoptysis

● Reactivation Tuberculosis preferentially affects the apices of the lung

9) Catheterization of bladder

● Bladder obstruction/distention commonly presents with dysuria and a tender suprapubic mass

● Treatment → Catheterization to relieve obstruction and void distended bladder

10) Complete Heart block

● P waves and QRS complexes are not associated with one another

● R-R interval is also regular

11) Hypomagnesemia

● Severely hypomagnesemia → suppressed PTH → hypocalcemia

● Alcoholism may lead to hypomagnesemia

12) Add simvastatin to her current regimen

● Age 40-75 with Diabetes Mellitus → Statins are indicated

● Statins blocks rate limiting enzyme (HMG-CoA Reductase) in cholesterol production

13) Hematogenous dissemination of distant infection

● Pott disease (extra-pulmonary tuberculosis)

● hematogenous seeding of a distant infectious focus → infection of the vertebral bone → contiguous spread to the intervertebral discs and adjacent vertebrae

14) Adequate control of blood pressure

● HTN → left ventricular hypertrophy (LVH) and ↓ ejection fraction (EF)

● Blood pressure control can prevent further permanent damage to heart

15) Tracheomalacia

● Weakening of supporting tracheal cartilage → collapse of trachea upon expiration

● Long term intubation → tracheal weakening and structural damage of tracheal cartilage

16) Cor Pulmonale

● Impaired function of the right ventricle (RV) due to pulmonary hypertension (pulmonary systolic pressure >25 mmHg)

● Symptoms: dyspnea, fatigue, exertional angina

● Signs: JVD, ascites, hepatomegaly, and pitting edema

17) 0.9% Saline

● Administration of IV Isotonic Saline prior to CT can generally help to restore renal perfusion and prevent renal damage via IV contrast (contrast nephropathy)

18) Nephrogenic diabetes insipidus

● Hypercalcemia can induce nephron damage → diabetes insipidus (DI) → polyuria, polydipsia, dehydration and volume depletion

● Nephrogenic DI → Failure of the kidney to respond to ADH

19) Crohn's disease

● Crohn’s Disease is characterized by chronic abdominal pain, diarrhea, weight loss and evidence of inflammation

20) Hot tub use

● Hypersensitivity pneumonitis caused by Mycobacterium avium complex (hot tub lung)

21) Add fluticasone

● Mild persistent asthma → add ICS (inhaled corticosteroid) to SABA (short acting beta agonist [eg, albuterol PRN])

22) Lymphangitis

● Lymphangitis → Inflammation of lymphatic channels that occurs as a result of infection or trauma at a site distal to the channel

● It will generally follow a pattern of red track marks along lymphatics

● Infection → ↑White Blood Cell (WBC), Left Shift, fever

23) Serum anti mitochondrial antibody assays

● Primary biliary cholangitis (PBC) characteristically presents with ↑ anti-mitochondrial antibodies and cholestatic pattern of liver injury (↑↑ ALP, ↑ AST and ALT) in middle-aged women

● Pathogenesis: autoimmune destruction of small bile ducts → intrahepatic cholestasis

● Presents insidiously with fatigue and pruritus

24) CT scan of abdomen

● ↑↑ Dehydroepiandrosterone (DHEAS) and no suppression of cortisol after overnight dexamethasone → Adrenal origin

● CT scan of abdomen to visualize Adrenal tumor secreting DHEAS

25) Alendronate

● Long term treatment of osteoporosis → bisphosphonates, calcium and vitamin D supplementation

● Bisphosphonates inhibit osteoclast activity

26) Nitrofurantoin therapy

● Treatment of uncomplicated cystitis → nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or Fosfomycin

27) Acute respiratory distress syndrome

● Acute Respiratory Distress Syndrome (ARDS) → Non - Cardiogenic lung injury → Inflammation → fluid leakage into alveoli

● Bilateral lung opacities are generally seen on Chest X- Ray

● Common risk factor for ARDS → trauma (i.e. Intubation)

● ARDS can present with hypoxemia with a PaO2/FiO2 ratio < 300mmHG