Pediatrics: NBME 1 and 2 thread

[1dayatatime]

Ivp was wrong on my exam. any response is appreciated. thanks guys. sorry for the typos on my phone

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[Vexare]

15 year old boy examination before school basketball participation. 5 year history of well control type 1 diabetes. Uses 25 units of intermediate acting insulin and 12 units of short acting insulin every morning and 15 units of intermediate acting insulin and 7 units of short acting insulin each afternoon. Hemoglobin a1c 6.5% 2 weeks ago. Examination on remarkable. If you request advice about how to decrease his risk of diabetes related complications during his basketball practices what is the most appropriate recommendations?

A decrease the insulin dosage by 10 to 15% only on practice days (prevent exercise-induced hypoglycemia by decreasing insulin before practice; the other answer choices are either impractical or unnecessary)
b limit exercise to 30 minutes
c measure urine glucose concentration every 30 minutes during exercise
d only participate in non contact sport
E switch to short acting insulin

3 month old boy two day history of fever and irritability. Previous well child examinations normal. 50 percentile for length-weight head circumference. 100.6 degrees Fahrenheit temperature, pulse 130 / minute, respirations 26, blood pressure 85 over 50. He is fussy. Urine obtained by catheterization. Urine analysis shows protein 1 + , red blood cells 0 to 3, white blood cells 20 to 50, bacteria few gram negative rods. Urine culture grows greater than 100,000 colonies of e.coli. Treatment with antibiotics is begun. Which of the following is the most appropriate next step in diagnosis?
A. Ivp
C renal ultrasound (indicated in all first-time UTIs in children <2 yrs)
d CT scan abdomen
e dimercapto succinic acid scan

 

[IndwellingCatheter]

some more from NBME 1:
1) 5 ear old with fatigue for 3 weeks, acute onset of fever and chills for 2 hours. Traveled to asia 1 month ago and received chloroquine. Exam shows pallor and splenomegaly. HCT 22, leuko 18, platelets 80. Diagnosis?
assay for strep
assay for heterophile
measure PT and PTT ( i was thinking gram negative DIC but this is wrong so is heterophile test the answer? seems strange for acute onset of fever and chills though)
Measure AST and ALT
thick and thin blood smears

I think this may be a case of Evan's syndrome. So you'd want to assay for heterophile anti-bodies. First Aid 2016 page 393 states that infectious mononucleosis can trigger a cold (IgM) mediated autoimmune hemolytic anemia. As for the thrombocytopenia, check out Evan's syndrome. Also, the fatigue and splenomegaly kind of go towards mono too. I'm not certain though.

 

[CodeRedDew]

I think this may be a case of Evan's syndrome. So you'd want to assay for heterophile anti-bodies. First Aid 2016 page 393 states that infectious mononucleosis can trigger a cold (IgM) mediated autoimmune hemolytic anemia. As for the thrombocytopenia, check out Evan's syndrome. Also, the fatigue and splenomegaly kind of go towards mono too. I'm not certain though.

I can't remember what I put for that question as my peds clerkship was a while back, but I'd go with thick and thin blood smears - want to assess for some infectious process given his recent travel history in an area that is notorious for chloroquine-resistant malaria.

 

[Vexare]

I think this may be a case of Evan's syndrome. So you'd want to assay for heterophile anti-bodies. First Aid 2016 page 393 states that infectious mononucleosis can trigger a cold (IgM) mediated autoimmune hemolytic anemia. As for the thrombocytopenia, check out Evan's syndrome. Also, the fatigue and splenomegaly kind of go towards mono too. I'm not certain though.

I can't remember what I put for that question as my peds clerkship was a while back, but I'd go with thick and thin blood smears - want to assess for some infectious process given his recent travel history in an area that is notorious for chloroquine-resistant malaria.

Agree with thick and thin blood smears. Not the classic demographic or presentation for mono (fatigue yes, but acute onset of fever and chills no). However, malaria seems to fit everything in terms of symptoms and labs (thrombocytopenia, anemia, leukocytosis). The history is also relevant because many areas of Asia are known to be chloroquine-resistant (use mefloquine, atovoquone-proguanil or doxycycline depending on demographics etc instead).

 

[YameCaco]

A 3 year old boy is brought to the ED with 4 days of lethargy vomiting and diarrhea. He is unable to keep his fluids down and has not produced urine in the past 24 hours. Temperature shows 101.8 F. Examination shows sunken eyes, tacky oral mucosa, and dry lips. There is no rash. Lungs are clear. There is a midsystolic ejection murmur. Hyperactive bowel sounds. Labs show:
Anion gap metabolic acidosis, BUN of 40, and +1 proteinuria.
What is the most likely cause of the patients renal failure?

A. Bacterial Toxin
B. Immune complex nephropathy
C. Impaired renal perfusion
D. Obstructive uropathy (wrong)
E. Renal vein thrombosis

 

[Apoplexy__]

A 3 year old boy is brought to the ED with 4 days of lethargy vomiting and diarrhea. He is unable to keep his fluids down and has not produced urine in the past 24 hours. Temperature shows 101.8 F. Examination shows sunken eyes, tacky oral mucosa, and dry lips. There is no rash. Lungs are clear. There is a midsystolic ejection murmur. Hyperactive bowel sounds. Labs show:
Anion gap metabolic acidosis, BUN of 40, and +1 proteinuria.
What is the most likely cause of the patients renal failure?

A. Bacterial Toxin
B. Immune complex nephropathy
C. Impaired renal perfusion
D. Obstructive uropathy (wrong)
E. Renal vein thrombosis

Impaired renal perfusion (prerenal AKI). Vomiting/diarrhea gets it on your radar, and the clinical exam findings you listed clinch it. In fact, any time the NBME lists "dry oral mucosa", you can bet your life and firstborn that the patient is hypovolemic with 100% certainty.

If you chose D because you thought it might be a stone, the fever and mentioned bowel sounds suggest against it and favor a primary GI problem (enteritis).

 

[frenchyn]

Does anyone know what is the answer to this question from Form 2?
a 36 hour old boy remains in the hospital because of jaundice that developed 12 hours after birth. He has received phototherapy for the past 24 hours. He as born at term following uncomplicated pregnancy. Mother is O RH pos, Infant is A RH pos, APGAR was 7-9 respectively. Exam today shows jaundice below the knees, spleen tip is 1cm below the costal margin. The remainder of the exam shows no abnormalities.
HCT 12hr = 45 , indirect bili 12hr = 11.8
HCT 24hr =39 , indirect bili 24 hr = 17.5
HCT 36hr = 30 , indirect bili 36 hr = 22.2

Direct Coombs test is positive!
whats the most appropriate management at this time?

Observation
continue phototherapy
exchange transfusion
IV Fluids
Splenectomy

Answer is exchange transfusion. Exchange transfusion criteria is 25 or with neurologic deficits, but this baby has been on phototherapy for 24 hours with no improvement, that means he most likely need exchange transfusion next.

 

[God's_Child]

One of my amazing friends answered some of these q's for me

-1week old newborn has 1 day history of difficulty breathing and discoloration of extremities. Appears ill, temp = 97.5, pulse = 160, resp = 52, BP = 60/36 in upper extremities and unobtainable in lower extremities. Skin, mucous membranes, and nail beds are dusky, and there is mottled discoloration of the extremeties. Moderate intercostal retractiosn and grunting. Lungs clear. Holosystolic murmuc along left sternal border. Liver edge palpable 4cm below costal margin.
pH = 7.15, CO2 = 28, O2 = 98
Intubation, mechanical ventilation, and iv fluid initiated, but no improvement one hour later. x-ray shows cardiomegaly and pulmonary congestion. Explanation of this condition?
a. closure of ductus arteriosus (this is coarctation)
b. deacreased pulm vascular resistance
c. increased pulm vascular resistance
d. intracardiac right to left shunt
e. opening of ductus arteriosus

"Closure of the ductus arteriosus. This is a classic presentation for a patient with coarctation of the aorta. When they are first born, blood is able to get past the coarctation because blood flow through the ductus arteriosus enters the aorta distal to the coarctation. When the ductus arteriosus closes in the first week of life, the left side of the heart then sees a massive increase in afterload, leading to heart failure"

16 y/o boy, 3 day hx of gain of pressure in left cheek. Hx of strep pneumo now w/ H. flu induced sinusitis. Most likely cause of patient's recurrent infections?

a) Combined immunodeficiency
b) Complement deficiency
c) Impaired cell-mediated immunity
d) Impaired chemotaxis
e) Impaired humoral immunity


"Impaired humoral immunity in the setting of Common Variable Immunodeficiency; in questions it will often be individuals in their teens or 20's who have recurrent sinopulmonary infections, most often with encapsulated organisms; Combine immunodeficiency = SCID = Recurrent infections with many types of organisms, failure to thrive, etc.; Complement deficiency classically leads to recurrent Neisseria infections; Impaired cell-mediated immunity will get same infections as HIV patient; Impaired chemotaxis will have same presentation as leukocyte adhesion deficiency (delayed umbilical cord separation, recurrent skin abscesses without pus, etc.)"