NBME Medicine Form 2 - Answers & Explanations
Updated: Nov 16, 2019
1) Enalapril • ACEi are protective against diabetic glomerulonephropathy
2) Idiopathic central diabetes insipidus • 50-100% increase in UOsm w/ DDAVP = Central DI • UOsm > 600 after deprivation = functional ADH (suggests primary polydipsia)
3) Amikacin • Aminoglycosides are nephrotoxic
4) Ambulatory ECG monitoring • Unexplained syncope without prodrome suggests arrhythmia as the cause
5) Bronchitis • Ronchi (low pitch = upper airway) are bronchiole airway sounds
• CAP would have CXR findings of consolidation/infiltrate
• Rales (crackles) + fever → pneumonia
6) Bicuspid aortic valve
• Systolic murmur peaking in late systole = crescendo-decrescendo murmur = Aortic Stenosis (causing slow-rising, sustained carotid pulse)
• Coarctation → brachial/femoral delay
• Rheumatic valve disease = MR w/ holosystolic murmur at apex
• VSD → holosystolic murmur w/ thrill at LSB
7) Measurement of serum creatinine concentration
• This patient already has signs of end-organ damage (HTN retinopathy) → screen other organs as well
• Serum creatinine indicates renal functioning
8) Decreased synaptic activity of cholinesterase
• Organophosphate toxicity
9) Administration of hepatitis B vaccine • IgM anti-HBc may be the sole maker of infection during the window period
10) Chronic myelogenous leukemia (CML) • Basophilia and Metamyelocytes < myelocytes = CML • No basophilia and Metamyelocytes > myelocytes = leukemoid reaction
11) PPD skin test • Patients with HIV should be screened for TB (regardless of CD4 count)
• If screening is positive → CXR to determine if latent or active
12) Duplex ultrasonography of the carotid arteries • U/S is cheaper than arteriography • Arteriography can cause embolization and risk another stroke
• CT with no abnormalities → no need for MRI
13) Decreased sensitivity, Increased specificity • Raising the cutoff point increases false negatives (decreases sensitivity) and decreases false positives (increases specificity)
14) Oxybutynin • Muscarinic antagonist that reduces bladder spasms and urge urinary incontinence (overactive bladder)
15) Abnormality of antiprotenase resulting in destruction of alveolar supporting structures
• Panacinar emphysema (alpha1-antitrypsin deficiency) → lower lobe destruction
• Centracinar emphysema (smoking induced) → upper lobe destruction
16) Increased vascular permeability
• ↑ CO with normal PCWP and LVEDV = distributive shock (most likely septicemia based on vitals and WBC)
• Inflammatory response → vasodilation → vascular content seeps into extravascular space → inability of oxygen to pass through → ↓ PO2
17) Empyema • Light’s criteria - fluid is exudative if ≥ 1 of the following is met:
• Pleural effusion protein/serum protein ratio > 0.5 • Pleural effusion LDH/serum LDH ratio > 0.6 • Pleural effusion LDH > 2/3 the upper limit of normal for serum LDH
• Empyema has pH < 7.2 (uncomplicated parapneumonic effusion has pH > 7.2)
• Not uncomplicated because gram-positive diplococci
18) Felty Syndrome • Rheumatoid arthritis + neutropenia + splenomegaly
19) Renal Failure • ESRD → uremic pruritis → scratching & excoriations • Kidney normally clears leptin; ESRD → ↑ leptin → anorexia
20) Prednisone therapy • Anti-smith antibodies = SLE
21) Adenocarcinoma of the lung • Most common primary lung cancer; more common in women and nonsmokers
• Peripherally located
22) Karyotype analysis • Klinefelter syndrome (XXY) → testicular atrophy, gynecomastia, tall, female hair distribution, developmental delay
23) Variant angina pectoris
• Aka prinzmetal or vasospastic angina → recurrent episodes of angina at rest
24) Abdominal paracentesis • Suspected spontaneous bacterial peritonitis in patients with cirrhosis that develop fever and change in mental status
• Suspected SBP → perform paracentesis → initiate empiric therapy with 3rd generation cephalosporin
25) Zinc
• Deficiency → ↓ alopecia, pustular skin rash, hypogonadism, impaired wound healing, impaired taste, immune dysfunction
26) Packed red blood cells • Hematocrit of 18% ≈ Hemoglobin of 6
• Hemoglobin < 7 → pRBC
27) Intravenous administration of 0.9% saline • Hypercalcemia → confusion; tx with fluids and calcitonin (short term) and bisphosphonates (long term)
• Indication for dialysis - AEIOU
• Acidosis, Electrolyte derangements (hyperkalemia), Intoxication (eg, ethylene glycol), Overload (of volume), Uremia
28) Varicella-zoster virus • Closely groups cluster = dermatomal distribution
29) Decreased myocardial contractility
• Immediately after an MI, the myocardium is stunned and won’t contract
• Stunned myocardium wont push out blood → atria pushing blood into an already filled ventricle → S3
30) Oral administration of an H2-receptor blocking agent
• Upright positioning alleviating symptoms → GERD
• Murmur is benign
31) Reassurance only
• Mid systolic click = MVP
• There is an association between MVP and anxiety (possibly → tachypnea), so all patients should be reassured about the benign nature of the condition
32) Pancreatitis • Presents with fever, tachycardia, hypotension, abdominal tenderness
• Alcoholism → ↑ risk • Saponification → hypocalcemia
• Complications include GI bleeding
33) Intravenous 0.9% saline • Short-term tx of hypercalcemia = normal saline hydration + calcitonin
• Restoring intravascular volume promotes urinary calcium excretion
• Long-term tx of hypercalcemia = bisphosphonates
34) Ipratropium therapy
• This anti-cholinergic is first line treatment in COPD exacerbation
35) MI within the past 6 months • This is a contraindication for surgery
36) Intravenous furosemide • JVD, bilateral crackles → pulmonary congestion/edema • Diuretics should be given to stop this patient from drowning in their own fluid
37) Avoidance of contact with weeds
• Linear vesicles 1 day after = allergic contact dermatitis (type IV HSR)
• Sporotrichosis takes days-weeks for a papule to form before spreading along lymphatic channel
38) Measurement of serum thyroid-stimulating hormone (TSH) concentration
• Heavy menstrual bleeding, weight gain, ↑ cholesterol, and myopathy are consistent with hypothyroidism
39) Decreased mean red cell volume • Heavy bleeding → ↓ Fe → Iron deficient anemia → ↓ MCV
40) Assess the patients decision making capacity • If a patient is having delusions, it would be practitioner malfeasance to let them leave AMA
41) Glucose concentration approximately equal to serum glucose concentration
• Cardiac insufficiency → transudate • Low glucose = exudative
42) 50% for each child, since PKD is autosomal dominant • This patient has a spontaneous, de novo, mutation (parents do no have it)
• The AR form is lethal very early on in life - this patient has the AD form
43) Surgical drainage • Pilonidal abscess should be drained surgically
• Wide excision if recurrent
44) Systemic sclerosis (scleroderma)
• Raynaud's + GI dysmotility and reflux are consistent with scleroderma
45) Aspiration of the knee joint
• Fall → hemarthrosis
• Blood is inflammatory to synovium → mild elevation in ESR (would be higher in a septic knee)
46) Osteonecrosis • Steroids → ↑ risk of avascular necrosis
• Crescent sign on right femoral head
47) Monospot • Teenager with sore throat, exudative pharyngitis and splenomegaly
48) Deficient mineralization of osteoid
• CKD → ↓ vitamin D → osteomalacia
• The acidosis in renal failure impairs the alkaline environment needed for bone mineralization
49) Fluid restriction • D5W + half NS → iatrogenic hypervolemic hyponatremia
• If asx, tx with fluid restriction (+/- salt tablets) • If altered mental status, 3% saline to slowly bring levels up
50) Clindamycin • Alcoholism → ↑ aspiration of oral anaerobes (which are higher in number in patients with poor dentition) → foul-smelling pneumonia with air-fluid levels
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