USMLE Daily Rounds

USMLE questions, clinical reasoning & high-yield concepts, every day. 🩺

Think like a doctor. Answer like an examiner.

[USMLE Daily Rounds @USMLERounds]

Which condition characteristically presents with diffuse ST-segment elevations and PR-segment depressions on ECG?

A. Acute myocardial infarction
B. Acute pericarditis
C. Pulmonary embolism
D. Dilated cardiomyopathy

[USMLE Daily Rounds @USMLERounds]

HbA1C vs Fructosamine

#MedTwitter

[USMLE Daily Rounds @USMLERounds]

HbA1C vs Fructosamine

#MedTwitter

[USMLE Daily Rounds @USMLERounds]

A 32-year-old pregnant female at 28 weeks gestation comes in for routine prenatal visit. She has type 1 diabetes mellitus.

Her self-monitoring blood glucose logs show:
* Fasting: 90 – 95 mg/dL
* 1 hour postprandial: 130 – 140 mg/dL

However, her lab HbA1c is reported as 4.8%.

The physician also notes she has homozygous sickle cell anemia (HbSS).

Which of the following laboratory markers would provide the most accurate assessment of her glycemic control over the past 2 – 3 weeks?

A) Fasting plasma glucose
B) Fructosamine
C) HbA1c repeat test
D) OGTT
E) Urine ketones

Explain your answer in the comment section.

[USMLE Daily Rounds @USMLERounds]

Which DRUG is KING of this kingdom? 👑

[USMLE Daily Rounds @USMLERounds]

Which DRUG is KING of this kingdom? 👑

[USMLE Daily Rounds @USMLERounds]

🚨 A 7-year-old boy comes for follow-up.

One week ago he had episodes of bloody diarrhea that have now resolved.

Today:
* Elevated BUN and serum creatinine
* Anemia + thrombocytopenia
* Coagulation studies completely normal

His peripheral blood smear is shown in the image below.

=> What’s the most likely diagnosis?
=> What finding do you expect to see on that smear?

Reply with your reasons.

[USMLE Daily Rounds @USMLERounds]

Most Likely Diagnosis:

✅ Acute Pulmonary Embolism (PE) with right ventricular strain

Why?
=> Hospitalization is a major risk factor for venous thromboembolism.
=> The sudden onset of pleuritic chest pain, dyspnea, tachycardia, tachypnea, and hypoxemia is classic for PE.

=> Markedly elevated D-dimer supports ongoing thrombosis.

=> Mildly elevated troponin and elevated BNP suggest right ventricular (RV) strain, indicating an intermediate-risk (submassive) PE.

[USMLE Daily Rounds @USMLERounds]

🚨 A 68-year-old man with hypertension and CKD is admitted for community-acquired pneumonia.

On hospital day 3 he develops acute pleuritic chest pain and dyspnea.

Vitals: HR 118, BP 138/82, RR 26, O₂ sat 92% on 4L NC.

Labs:
* D-dimer markedly elevated
* Troponin mildly elevated
* BNP elevated
* Cr 2.8 mg/dL (baseline 1.9)

=> What is the most likely diagnosis?
=> What's the appropriate next step?

[USMLE Daily Rounds @USMLERounds]

🚨 A 7-year-old boy comes for follow-up.

One week ago he had episodes of bloody diarrhea that have now resolved.

Today:
* Elevated BUN and serum creatinine
* Anemia + thrombocytopenia
* Coagulation studies completely normal

His peripheral blood smear is shown in the image below.

=> What’s the most likely diagnosis?
=> What finding do you expect to see on that smear?

Reply with your reasons.

[USMLE Daily Rounds @USMLERounds]

Answer: B) Fructosamine ✅

=> HbA1c is unreliable in patients with sickle cell disease (HbSS) because the shortened red blood cell lifespan reduces the time available for hemoglobin glycation, resulting in a falsely low HbA1c.

=> Fructosamine measures glycated serum proteins (primarily albumin) and reflects average blood glucose over the previous 2-3 weeks, independent of red blood cell survival.

=> In this patient, the HbA1c of 4.8% is falsely reassuring despite glucose logs suggesting higher average glucose levels. Therefore, fructosamine provides the most accurate assessment of recent glycemic control.

[USMLE Daily Rounds @USMLERounds]

A 32-year-old pregnant female at 28 weeks gestation comes in for routine prenatal visit. She has type 1 diabetes mellitus.

Her self-monitoring blood glucose logs show:
* Fasting: 90 – 95 mg/dL
* 1 hour postprandial: 130 – 140 mg/dL

However, her lab HbA1c is reported as 4.8%.

The physician also notes she has homozygous sickle cell anemia (HbSS).

Which of the following laboratory markers would provide the most accurate assessment of her glycemic control over the past 2 – 3 weeks?

A) Fasting plasma glucose
B) Fructosamine
C) HbA1c repeat test
D) OGTT
E) Urine ketones

Explain your answer in the comment section.

[USMLE Daily Rounds @USMLERounds]

@Chiragrx07 Great

[USMLE Daily Rounds @USMLERounds]

🫀 Boot-shaped heart on CXR = ?

What are the 4 classic features?

Drop your answers.

[USMLE Daily Rounds @USMLERounds]

Why not the others?

A. Adenosine deaminase => SCID

B. Glucose-6-phosphatase => Von Gierke disease

D. Xanthine oxidase deficiency => Xanthinuria (low uric acid, not gout)

[USMLE Daily Rounds @USMLERounds]

Answer: C. HGPRT

=> The combination of developmental delay, self-mutilation (lip/finger biting), hyperuricemia, and gout is classic for Lesch-Nyhan syndrome.

=> Lesch-Nyhan syndrome is caused by deficiency of Hypoxanthine-Guanine Phosphoribosyltransferase (HGPRT), a purine salvage enzyme.

=> Loss of HGPRT leads to increased purine degradation and excess uric acid production, causing gout and neurologic manifestations.

[USMLE Daily Rounds @USMLERounds]

Answer: B. Severe Combined Immunodeficiency (SCID)

=> The thymus is the site of T-cell maturation, so an absent thymic shadow suggests a profound T-cell deficiency.

=> SCID is characterized by severe defects in both T-cell and B-cell function, leading to severe lymphopenia and recurrent infections early in life.

=> On chest X-ray, infants with SCID often have an absent thymic shadow due to lack of normal thymic development.

[USMLE Daily Rounds @USMLERounds]

An absent thymic shadow on a newborn X-ray combined with severe lymphopenia indicates which defect?

A. Bruton agammaglobulinemia
B. Severe combined immunodeficiency (SCID)
C. Chronic granulomatous disease
D. C5-C9 complement deficiency

[USMLE Daily Rounds @USMLERounds]

@_uakbar ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What’s the most common cause of pericarditis in a young healthy patient vs an older one?

[USMLE Daily Rounds @USMLERounds]

Which condition characteristically presents with diffuse ST-segment elevations and PR-segment depressions on ECG?

A. Acute myocardial infarction
B. Acute pericarditis
C. Pulmonary embolism
D. Dilated cardiomyopathy

[USMLE Daily Rounds @USMLERounds]

@medicinedr18 ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What drug is the first line of treatment?

[USMLE Daily Rounds @USMLERounds]

@ajlkfad2333 ✅ Correct

Diffuse concave ST elevation + PR depression = pericarditis until proven otherwise.

What’s one ECG finding that would make you worry about tamponade instead?