USMLE Step 3 exam 2024 When would you order a head CT with or without contrast? - correct answer ✔✔ With - looks for abscesses or intracranial masses
WITHOUT - looks for acute bleeding which appears white. Contrast also appears white and can obscure bleeding. Like in intracranial hemorrhage
Parents bring teen daughter to ED for cutting herself. No intent to commit suicide per daughter. Does she require hospitalization while you work her up for safety reasons? - correct answer ✔✔ NO. There is no intent to commit suicide in curing disorders. Just done to cope w/emotions. Pt will need full psych work up.
Metzner's index - correct answer ✔✔ MCV/RBC. Helps to differentiate IDA from beta-thalassemia. Alpha or Beta-thalassemia if <13
IDA if > 13
The 4 types of shock and how they affect RAP, PCWP, CI, SVR - correct answer ✔✔ Explain what SPIN and SNOUT mean for specificity and sensitivity - correct answer ✔✔ Specificity = TN/(TN+FP)
- SP-P-IN - if a test is positive for a disease then it rules IN that disease. Use a highly specific test after a screening test to confirm that the person actually has that disease
- low rate of false positives
Sensitivity = TP/(TP+FN)
- SN-N-OUT - if a test is negative for a disease then it rules OUT that disease. Use a highly sensitive test on screening tests to rule out diseases
- low rate of false negatives what is the formula for anion gap? what is normal anion gap? - correct answer ✔✔ Na+ - (Cl- + HCO3-)
What is the order for family members designated as surrogate? - correct answer ✔✔ Spouse, adult children, parent, adult sibling, nearest living relative, close friend
Define: Hirsutism - correct answer ✔✔ Hirsutism (HUR-soot-iz-um) is a condition in women that results in excessive growth of dark or coarse hair in a male-like pattern
What is the normal range for bicarbonate? - correct answer ✔✔ 22-28
How can you tell the difference btw A fib w/RVR and multifocal atrial tachycardia? - correct answer ✔✔ Both are narrow complex tachycardias (QRS<120 bc atrial) w/irregular R-R intervals
AFRVR - No P waves
MAT - ≥3 different types of P waves seen, HR>100
How can you tell if a question is asking you to calculate the relative risk? The relative risk reduction? Or the absolute risk reduction? - correct answer ✔✔ If the question says "What is the reduction in risk?" then it wants the RRR.
If the question says "What is the magnitude of risk between these two treatment groups?" then it wants
RR
- RR = risk in exposed group/risk in control group
If the question says "What is the ARR?" Then it wants ARR
What is the mechanism behind tertiary hyperparathyroidism and what is the treatment? - correct answer✔✔ - Occurs in CKD and renal osteodystrophy when you have inability to excrete phosphate and inability to convert inactive vitamin D3 to active 1,25 dihydroxyvitamin D resulting in hypercalcemia due to bone losses of Ca2+ - Initially you start making more PTH in response to hypocalcemia and hyperphosphatemia. Then as Ca2+ and PO43- increase you have uncontrolled secretion of PTH and elevation in Ca2+ and PO43-
- The only treatment is PARATHYROIDECTOMY bc the parathyroid will just continue making PTH forever. A renal transplant will not fix this
Which fracture happens from falling on flexion vs extension of the wrist? - correct answer ✔✔ Flexion - bending wrist forward. Smith fracture. Extension - falling on an outstretched hand. They will term this "tripping and falling forward", they don't say outstretched hand, you are to assume it. Colles fracture and Ulnar styloid fracture
In a septic patient with hyperglycemia how can you tell if the hyperglycemia is due to undiagnosed DM? What is another cause of hyperglycemia in these patients? - correct answer ✔✔ - Septic patients often have high BG bc of elevated cortisol release, pro-inflammatory cytokines and catecholamine release but they may not actually have DM. This is called STRESS HYPERGLYCEMIA
- If the pt has random BG >200 + signs of hyperglycemia like polyuria, polydipsia, weight loss (in children w/DM1), polyphagia OR HbA1c ≥ 6.5 OR fasting plasma glucose >126 OR oral glucose tolerance test 2 hr later w/BG>200 then this is DM
- Always check an A1c and this will tell you if there is a chronic elevation in BG signifying undx'd DM1 or 2
Slipped Capital Femoral Epiphysis on X ray and treatment - correct answer ✔✔ IMMEDIATE SURGICAL PINNING
56 yo M w/ARDS intubated in ICU for 7d then extubated. 1 wk later he is irritable and confused in evenings and prescribed zolpidem to help w/sleeping. Montreal Cognitive assessment shows 25/30 w/deficits in memory and attention. He has flattened affect and psychomotor retardation. Long term prognosis? - correct answer ✔✔ Dx: Post-intensive Care Syndrome (PICS)
Risk factors: ARDS, prolonged ventilation, ICU delirium
Pathophysiology: CNS hypoxia, neuroinflmmation, metabolic dysruption, massive inflammation
Outcome: LIKELY TO HAVE MEMORY AND CONCENTRATION DEFECTS FOR YEARS - Usually they have deficits in one or more of the three areas for years
How can you tell inflammatory acne from comedonal and nodular acne? What is the difference in treatment? - correct answer ✔✔ - Basically inflammatory looks almost the same as comedomal but in inflammatory the lesions are inflamed papules and pustules. In comedomal they start off as closed or open comedones but can then progress to inflamed populous and nodules.
- For both comedonal and inflammatory you give topical retinoids. For inflammatory you add benzoyl peroxide and then topical antibiotics
- you never give PO abx except for nodular aka cystic acne
- in general the tx steps for all types are in order: topical benzoyl peroxide>topical retinoids > topical abx
> PO abx > PO retinoids
How do you determine the next test to perform after diagnosing unstable angina or NSTEMI? - correct answer✔✔ - Calculate the TIMI score to determine if pt needs to go to cath rn
What CD4 count do AIDS opportunistic infections develop? - correct answer ✔✔ <100
The USMLE does not give you WBC count for CSF. What WBC count is suggestive of bacterial meningitis?
- correct answer✔✔ >1000
Immune reconstitution syndrome - correct answer ✔✔ Immune Reconstitution Syndrome, Immune Restoration Disease. In HIV infection, an exaggerated inflammatory reaction to a disease-causing microorganism that sometimes occurs when the immune system begins to recover following treatment with antiretroviral (ARV) drugs.
What are the only antibiotics that cover pseudomonas? - correct answer ✔✔ - Anti-pseudomonal penicillins
- Cephalosporins - 3rd & 4th gen
- Monobactams - Carbapenems
- Fluoroquinolones
WITHOUT - looks for acute bleeding which appears white. Contrast also appears white and can obscure bleeding. Like in intracranial hemorrhage
Parents bring teen daughter to ED for cutting herself. No intent to commit suicide per daughter. Does she require hospitalization while you work her up for safety reasons? - correct answer ✔✔ NO. There is no intent to commit suicide in curing disorders. Just done to cope w/emotions. Pt will need full psych work up.
Metzner's index - correct answer ✔✔ MCV/RBC. Helps to differentiate IDA from beta-thalassemia. Alpha or Beta-thalassemia if <13
IDA if > 13
The 4 types of shock and how they affect RAP, PCWP, CI, SVR - correct answer ✔✔ Explain what SPIN and SNOUT mean for specificity and sensitivity - correct answer ✔✔ Specificity = TN/(TN+FP)
- SP-P-IN - if a test is positive for a disease then it rules IN that disease. Use a highly specific test after a screening test to confirm that the person actually has that disease
- low rate of false positives
Sensitivity = TP/(TP+FN)
- SN-N-OUT - if a test is negative for a disease then it rules OUT that disease. Use a highly sensitive test on screening tests to rule out diseases
- low rate of false negatives what is the formula for anion gap? what is normal anion gap? - correct answer ✔✔ Na+ - (Cl- + HCO3-)
What is the order for family members designated as surrogate? - correct answer ✔✔ Spouse, adult children, parent, adult sibling, nearest living relative, close friend
Define: Hirsutism - correct answer ✔✔ Hirsutism (HUR-soot-iz-um) is a condition in women that results in excessive growth of dark or coarse hair in a male-like pattern
What is the normal range for bicarbonate? - correct answer ✔✔ 22-28
How can you tell the difference btw A fib w/RVR and multifocal atrial tachycardia? - correct answer ✔✔ Both are narrow complex tachycardias (QRS<120 bc atrial) w/irregular R-R intervals
AFRVR - No P waves
MAT - ≥3 different types of P waves seen, HR>100
How can you tell if a question is asking you to calculate the relative risk? The relative risk reduction? Or the absolute risk reduction? - correct answer ✔✔ If the question says "What is the reduction in risk?" then it wants the RRR.
If the question says "What is the magnitude of risk between these two treatment groups?" then it wants
RR
- RR = risk in exposed group/risk in control group
If the question says "What is the ARR?" Then it wants ARR
What is the mechanism behind tertiary hyperparathyroidism and what is the treatment? - correct answer✔✔ - Occurs in CKD and renal osteodystrophy when you have inability to excrete phosphate and inability to convert inactive vitamin D3 to active 1,25 dihydroxyvitamin D resulting in hypercalcemia due to bone losses of Ca2+ - Initially you start making more PTH in response to hypocalcemia and hyperphosphatemia. Then as Ca2+ and PO43- increase you have uncontrolled secretion of PTH and elevation in Ca2+ and PO43-
- The only treatment is PARATHYROIDECTOMY bc the parathyroid will just continue making PTH forever. A renal transplant will not fix this
Which fracture happens from falling on flexion vs extension of the wrist? - correct answer ✔✔ Flexion - bending wrist forward. Smith fracture. Extension - falling on an outstretched hand. They will term this "tripping and falling forward", they don't say outstretched hand, you are to assume it. Colles fracture and Ulnar styloid fracture
In a septic patient with hyperglycemia how can you tell if the hyperglycemia is due to undiagnosed DM? What is another cause of hyperglycemia in these patients? - correct answer ✔✔ - Septic patients often have high BG bc of elevated cortisol release, pro-inflammatory cytokines and catecholamine release but they may not actually have DM. This is called STRESS HYPERGLYCEMIA
- If the pt has random BG >200 + signs of hyperglycemia like polyuria, polydipsia, weight loss (in children w/DM1), polyphagia OR HbA1c ≥ 6.5 OR fasting plasma glucose >126 OR oral glucose tolerance test 2 hr later w/BG>200 then this is DM
- Always check an A1c and this will tell you if there is a chronic elevation in BG signifying undx'd DM1 or 2
Slipped Capital Femoral Epiphysis on X ray and treatment - correct answer ✔✔ IMMEDIATE SURGICAL PINNING
56 yo M w/ARDS intubated in ICU for 7d then extubated. 1 wk later he is irritable and confused in evenings and prescribed zolpidem to help w/sleeping. Montreal Cognitive assessment shows 25/30 w/deficits in memory and attention. He has flattened affect and psychomotor retardation. Long term prognosis? - correct answer ✔✔ Dx: Post-intensive Care Syndrome (PICS)
Risk factors: ARDS, prolonged ventilation, ICU delirium
Pathophysiology: CNS hypoxia, neuroinflmmation, metabolic dysruption, massive inflammation
Outcome: LIKELY TO HAVE MEMORY AND CONCENTRATION DEFECTS FOR YEARS - Usually they have deficits in one or more of the three areas for years
How can you tell inflammatory acne from comedonal and nodular acne? What is the difference in treatment? - correct answer ✔✔ - Basically inflammatory looks almost the same as comedomal but in inflammatory the lesions are inflamed papules and pustules. In comedomal they start off as closed or open comedones but can then progress to inflamed populous and nodules.
- For both comedonal and inflammatory you give topical retinoids. For inflammatory you add benzoyl peroxide and then topical antibiotics
- you never give PO abx except for nodular aka cystic acne
- in general the tx steps for all types are in order: topical benzoyl peroxide>topical retinoids > topical abx
> PO abx > PO retinoids
How do you determine the next test to perform after diagnosing unstable angina or NSTEMI? - correct answer✔✔ - Calculate the TIMI score to determine if pt needs to go to cath rn
What CD4 count do AIDS opportunistic infections develop? - correct answer ✔✔ <100
The USMLE does not give you WBC count for CSF. What WBC count is suggestive of bacterial meningitis?
- correct answer✔✔ >1000
Immune reconstitution syndrome - correct answer ✔✔ Immune Reconstitution Syndrome, Immune Restoration Disease. In HIV infection, an exaggerated inflammatory reaction to a disease-causing microorganism that sometimes occurs when the immune system begins to recover following treatment with antiretroviral (ARV) drugs.
What are the only antibiotics that cover pseudomonas? - correct answer ✔✔ - Anti-pseudomonal penicillins
- Cephalosporins - 3rd & 4th gen
- Monobactams - Carbapenems
- Fluoroquinolones
