CVPR

Question 1

Causes of anion gap metabolic acidosis

Answer 1

MUDPILES - methanol (formic acid), uremia, DKA, propylene glycol, iron tablets/isoniazid, lactic acid, ethanol/ethylene glycol, salicylates

Question 2

Causes of non-anion gap metabolic acidosis

Answer 2

HARDASS - hyperalimentation, Addison disease, renal tubular acidosis, diarrhea, acetazolamide, spironolactone, saline infusion

Question 3

Anion gap calculation and normal range

Answer 3

Na+ - (Cl- + HCO3-) should be between 6-12

Question 4

Causes of metabolic alkalosis (H+ loss/HCO3- excess)

Answer 4

Vomiting, loop diuretics, antacid use, hyperaldosteronism

Question 5

Respiratory compensation for metabolic acidosis

Answer 5

Winters formula: PCO2 = 1.5[HCO3-] + 8 +/- 2. If PCO2 > predicted then there is a concomitant respiratory acidosis. If PCO2 < predicted then there is a concomitant respiratory alkalosis

Question 6

Congenital diaphragmatic hernia

Answer 6

Failure of the pleuroperitoneal canal (foramen of Bochdalek) to close. Causes protrusion of abdominal viscera into the chest (usually on left side). Often causes pulmonary hypoplasia which can lead to death because of lack of space for lung development.

Question 7

Bronchoconstricting chemicals

Answer 7

Leukotriene C4, D4, and E4. Blocking 5-lipoxygenase or inhibiting leukotriene receptors can alleviate asthma symptoms.

Question 8

Fick principle

Answer 8

The rate of O2 utiliation by the body is equal to the cardiac output time the difference between the O2 content of the systemic arterial blood and the oxygen content of the systemic venous blood. O2 consumption (whole body) = CO x (arterial oxygen content - venous oxygen content)

Question 9

R-R interval

Answer 9

Tells you how many seconds each heart beat takes. The inverse is beats/sec and you can multiply that by 60 and it’s your heartrate

Question 10

Primary metabolic disturbance vs primary respiratory disturbance of pH

Answer 10

If the pH and PaCO2 change in the same direction (i.e. both increase) then this is a primary metabolic disturbance. If they change in opposite directions than it is a primary respiratory disturbance

Question 11

Clonidine

Answer 11

Third line last resort antihypertensive agent that can be given as a transdermal patch. A2 agonist that decreases PVR, HR, and BP. Can cause dry mouth, sedation, and sexual dysfunction. Sudden discontinuation can cause sudden increase in sympathetic outflow and rebound hypertension.

Question 12

Trimethoprim-sulfamethoxazole

Answer 12

First line therapy for uncomplicated UTIs. Blocks synthesis of folate which is essential for nucleotide synthesis. TMP inhibits bacterial dihydrofolate reductase and SMX inhibits dihydropteroate synthase. Can cause megaloblastic anemia from folate inhibition.

Question 13

Vancomycin

Answer 13

Blocks peptidoglycan synthesis by binding D-ala-D-ala in cell wall precursors. Use restricted to multidrug resistant gram-positive bacteria.

Question 14

Coxsackievirus

Answer 14

Picornavirus. Positive, single-stranded, naked, icosahedral RNA viruses. Common cause of pericarditis preceded by a viral URI. Can also cause viral myocarditis.

Question 15

Rheumatic heart disease/Rheumatic fever

Answer 15

Valvular damage, rash, chorea, fever, and polyarthritis are characteristic of rheumatic fever. Later you can develop CHF due to valve damage (esp mitral and aortic). Commonly associated with Aschoff bodies, which are noncaseating granulomas with multinucleated giant cells, Anitschokow cells (enlarged macrophages with ovoid, wavy, rod-like nucleus, and increased ASO titers. Consequence of pharyngeal infection with group A streptococcus pyogenes. Type II hypersensitivity with antibodies that react to M protein in strep that cross react to self antigens in the heart (molecular mimicry). Jones criteria -> joints (migratory polyarthritis), heart (Carditis), subcutaneous skin nodules, erythema marginatum, and sydenham chorea. Treat with penicillin.

Question 16

Sarcoidosis

Answer 16

Multiorgan inflammatory disorder of unknown origin. Most frequently involves lung but can also affect lymph nodes, skin, eyes, kidneys, heart, and CNS. GRAIN -> gamma-globulinemia, RA, elevated angiotensin-converting enzyme levels, interstitial fibrosis, and noncaseating granulomas. Often has bilateral hilar lymphadenopathy of the lungs. Treated with immunosuppressants such as glucocorticoids or methotrexate for more chronic disease.

Question 17

Pneumocystis jirovecii

Answer 17

causes pneumocystis pneumonia. Yeast-like fungus. Most infections are asymptomatic but can be symptomatic in immunosuppressed patients. Diffuse, bilateral ground-glass opacities. Diagnosed by lung biopsy or lavage which yields disc-shaped yeast seen on methenamine silver stain. Treated with TMP-SMX or pentamidine for people with sulfa allergies.

Question 18

Prinzmetal (variant) angina

Answer 18

Coronary artery vasospasm. Occurs at rest. Chest pain with sudden onset that radiates to left shoulder or jaw that is relieved by sublingual nitroglycerin. Often in younger patients. Transient ST elevation on ECG. Smoking is a risk factor and triggers can include cocaine, alcohol and triptans. Treat with Ca2+ channel blockers, nitrates, and smoking cessation.

Question 19

Granulomatosis with polyangiitis

Answer 19

Upper respiratory tract: perforation of nasal septum, chronic sinusitis, otitis media, mastoiditis. Lower respiratory tract: hemoptysis, cough, dyspnea
Renal: hematuria, red cell casts. Triad: focal necrotizing vasculitis, necrotizing granulomas in the lung and upper airway, necrotizing glomerulonephritis. PR3-ANCA/c-ANCA positive. Large nodular densities on CXR. Treat with cyclophosphamide/corticosteroids.

Question 20

Cystic fibrosis

Answer 20

AR defect in CFTR gene on chromosome 7 (most commonly deletion of Phe508. Most common lethal genetic disease in caucasian population. Leads to a misfolded protein that is retained in RER and not transported to cell membrane. Leads to decreased Cl- secretion and thus increase in Na+ and H2O reabsorption in epithelial cells. Leads to secretion of thick mucus into lungs/GI tract. Cl- concentration >60 mEq/L in sweat is diagnostic. Can also cause contraction alkalosis and hypokalemia because more K and H are secreted in place of Na+ and H2O. Increased immunoreactive trypsinogen. Predisoposes to Pseudomonas infections, bronchitis, and bronchiectasis, malabsorption with steatorrhea, biliary cirrhosis, liver disease, infertility in men/subfertility in women, nasal polyps, clubbing of nails. Can treat with chest physiotherapy, albuterol, dornase alfa (DNAse), and hypertonic saline. Z pack and ibuprofen/pancreatic enzymes can slow progression

Question 21

Acute poststreptococcal glomerulonephritis

Answer 21

Most frequently in children. Occurs 2-4 weeks after group A streptococcal infection or skin. Resolves spontaneously. Type III hypersensitivity reaction. Presents with peripheral and periorbital edema, cola-colored urine, hypertension. Positive strep titers, decreased C3 (complement) levels. LM - glomeruli enlarged and hypercellular. IF - starry sky/lumpy bumpy granular appearance due to IgG, IgM, and C3 deposition along GBM and mesangium. EM - subEPithelial immune complex humps

Question 22

Most common cause of bronchiolitis in children < 5 years old

Answer 22

RSV (paramyxoviridae). Can cause rhinorrhea, fever, cough, sneezing, cyanosis, breathing difficulty, bilateral wheezing/rhonchi. Pathogenesis is due to surface protein F, which causes respiratory epithelial cells to fuse and form multinucleated cells. Palivizumab (Ab against F protein) prevents RSV pneumonia in premature infants. Treatment is ribavirin. Parainfluenza (croup), measles, and mumps are all paramyxoviridae and also have F protein.

Question 23

Kawasaki disease

Answer 23

Medium vessel vasculitis. Often seen in Asian children under 4 years old. CRASH and burn = Conjunctival injection, Rash (polymorphous -> desquamating), Adenopathy (cervical), Strawberry tongue (oral mucositis), Hand-foot changes (edema, erythema), fever. May develop coronary artery aneurysms; thrombosis or rupture can cause death. Treat with IVIG and aspirin

Question 24

Aspergillus fumigatus

Answer 24

Causes invasive aspergillosis in immunocompromised (neutropenic) patients with chronic granulomatous disease. Septate hyphae that branch at 45 degrees. Produces conidia in radiating chains at the end of conidiophore. Some species produce aflatoxins which are associated with HCC. CT can show an air-crescent sign which is an area of consolidation with an air pocket in the shape of a crescent around it (reabsorption of necrotic tissue following an invasive fungal infection). This is usually a good sign as it is a sign of resolving neutropenia.

Question 25

Libman-Sacks Endocarditis

Answer 25

Nonbacterial, small verrucous thrombi usually on mitral or aortic valve and can be present on either surface of the value (but typically the undersurface). Seen in people with SLE.