NBME Medicine Form 4 - Answers & Explanations
Updated: Aug 28, 2020
1) X-ray of the chest • Clubbing of fingers & toes = hypertrophic osteoarthropathy
2) Hypercarbia • O2 supplementation → ↓ respiratory drive → retained CO2 (hypercarbia)
3) Mycoplasma pneumoniae • young, non-productive cough, low grade fever with patchy or diffuse interstitial infiltrate = atypical mycoplasma pneumonia
• CXR looks worse than the patient feels
4) Legionella pneumophila • Pneumonia + diarrhea = legionnaires disease • Pulse temperature dissociation (fever with relative bradycardia)
5) Renal artery stenosis • Carotid bruit = atherosclerosis of carotid artery; atherosclerosis in one vessel indicates multi vessel disease → RAS secondary to atherosclerosis
6) Erythropoietin • Corrected reticulocyte count is ~1.2%, meaning there is not enough marrow stimulation • Chronic kidney disease → ↓ EPO production
7) Pamidronate • Short term treatment of hypercalcemia is normal saline and calcitonin
• Long term treatment of hypercalcemia is bisphosphonates
8) Drug induced neutropenia • PTU and methimazole → neutropenia
9) Villous atrophy in the small bowel • D-xylose depends only on viable mucosa (not enzymatic breakdown) for absorption in the proximal small bowel • Celias disease → villous blunting → ↓ D-xylose absorption
10) Three-drug antiretroviral therapy only
• Start antiretrovirals straight away regardless of CD4 count
• Need to use three because of increased resistance
• No need for P. jiroveci prophylaxis because CD4 count >200
11) Direct current countershock • Direct current countershock = DC cardioversion • Wide QRS complex = ventricular tachycardia → shock
12) Choledocholithiasis
• This patients high amylase indicates there is a blockage at the pancreatic duct, and the elevated direct bilirubin indicates a blockage of the common bile duct
13) Left medial longitudinal fasciculus • The right PPRF send a signal to the left medial rectus via the left MLF; weakness of left adduction upon right gaze indicates a problem at the left MLF
14) Calcification of a bicuspid aortic valve • Systolic ejection murmur at the young age of 19 indicates a congenital cause
• Aortic stenosis (due to calcified bicuspid aortic valve) → ↑ LV pressure → hypertrophy and stiffening of the LV → S4
15) Supraspinatus tendon • Pain over lateral deltoid, awaking at night (lying on affected shoulder) and pain elicited from abduction against resistance = rotator cuff pathology
16) Acute tubular necrosis
• 3+ blood with no RBC’s → rhabdo → myoglobinuria → ATN
17) Seborrheic dermatitis • Usually appears on hairy areas (eg, scalp behind ears, beard, etc.)
• Greasy looking yellowish scaly rash • Associated with HIV & Parkinson disease
18) Switch from heparin to direct thrombin inhibitor therapy • Heparin-induced thrombocytopenia → stop all heparin products and start a direct thrombin inhibitor or fondaparinux
19) Gout
• Chronic alcohol use with asymmetric arthritis
20) MRI of the lumbosacral spine
• Compression of sacral nerves by tumor → Cauda Equine syndrome (B/L paralysis and numbness of LE, urinary incontinence (overflow), saddle anesthesia, absent DTRs below the knee)
• MRI is the modality of choice to diagnose nerve root compression
21) α1-antitrypsin deficiency
• Increased lucency at lung bases in young patient → panacinar emphysema
22) Hodgkin disease
• Single enlarged LN, pruritis, and absence on pharyngeal erythema make Hodgkin disease more likely than mono
• Pathologic lymphocytes are confined to affected nodes (unless a leukemic transformation occurs) which is why leukocyte count is not elevated
23) Addition of lisinopril to the medication regimen • ACEi → ↓ glomerular hyper-filtration associated with DM
24) Lisinopril therapy
• Hemorrhagic stroke are commonly caused by HTN
• Although weight reduction of 10kg lowers BP by 5-20 mmHg, this patient has already suffered a complication of HTN and must be treated aggressively with BP medication (while he continues to make lifestyle changes)
25) Nonketotic hyperosmolar state
• Glucose > 600 = HHS
26) Autoinfection • Reinfected himself from scratching his foot and then touching his groin area
• Resistance is unlikely since the rash went away with the first treatment
27) Autonomous T4 production
• Toxic adenoma
28) Discharge home with home hospice care • Without treatment, the life expectancy for stage IV non-small cell lung carcinoma is < 6 months
29) Upper endoscopy
• Alarm symptoms (dysphagia, weight loss, or anemia) → EGD
30) Rhabdomyolysis
• 2+ blood with no RBCs = myoglobinuria from rhabdo
31) Prosthetic aortic valve • Adenocarcinoma (hypercoagulable state) and prosthetic valves both require anticoagulation, but prosthetic valves require a higher INR - prosthetic valves have a higher chance of throwing a clot
32) Fine-needle aspiration of the lesion
• Cancer risk factors → FNA
• Normal or elevated TSH → FNA
• Low TSH → Iodine 123 scintigraphy (cold nodules → FNA, hot nodule → treat hyperthyroidism)
33) Weight loss • Weight loss → ↓ pressure on joints → ↓ risk of OA
34) Prerenal azotemia • Na < 10, FENa < 1, BUN/CR ration >20
35) Obstruction of the small bowel • ↑ bowel movement = SBO, ↓ bowel movement = ileus • Multiple bowel procedures → ↑ risk of adhesions (#1 cause of SBO)
36) Paroxysmal ventricular tachycardia • Suspect cardiac etiology in someone with hx heart disease and abnormal EKG (Q waves are from previous MI)
37) Influenza virus
• Should be given annually
38) Increasing the dose of lisinopril • Lisinopril is kidney protective and lowers BP - her BP remains above the goal of <140/<90
• Fixed split S2
40) Decreased vascular compliance
• ↑ age → stiffening of vessels → ↓ compliance
41) Debridement of the ulcer
• Area of necrosis (eschar) needs to be removed
42) Chlamydia trachomatis • Need giemsa stain to visualize chlamydia (gram stain does not work)
• Would show intracellular organisms if it were Neisseria gonorrhoeae
43) Oral contraceptive therapy • OCPs prevent endometrial hyperplasia due to unopposed estrogen in PCOS
• Clomiphene or metformin can be used to induce ovulation
44) Group B at year 3-4
• Steepest negative slope = biggest decline in survival
• The survival rate in any year for any group is the slope of the survival curve during that time period for that group. Group B at year 3-4 has the most negative slope which translates to biggest decline in survival, or poorest survival rate.
45) Labetalol • Decreases HR, BP and LV contractility (less aortic wall stress) • Nitro/hydralazine lower BP via vessel wall dilation, which can cause further stress and exacerbate the tear on the aorta
46) Laryngoscopy and endotracheal intubation
• This patient has epiglottitis - the airway must be secured
47) Quantitative immunoglobulin assay
• CLL → hypogammaglobulinemia
48) Chest x-ray
• Pulmonary barotrauma can occur if the diver fails to expel air from lungs during ascent; as he swims up to the surface the volume of gas expands → pneumothorax
49) Endoscopic retrograde cholangiopancreatography (ERCP)
• Symptomatic pseudocysts are drained with ERCP
50) Diverticulitis • Chronic constipation, LLQ pain, tenderness, bloody stools, fever
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