Pediatric Cardiology and Hematology

Question 1

The NEW, FANCY test for hereditary spherocytosis

Answer 1

• Eosin-5-maleimide binding test
• Analyzes the interaction between a dye and certain proteins on the RBC surface through flow cytometry
• Fast, highly sensitive, highly specific
• Now preferred to the osmotic fragility study for diagnosis of hereditary spherocytosis

Question 2

Bleeding time is a simple but sensitive marker of ___

Answer 2

Bleeding time is a simple but sensitive marker of platelet function

Do not confuse this for a coagulation test

Question 3

Eisenmenger syndrome may occur in. . .

Answer 3

• VSD (within months of birth)
• ASD (later in life, often young adulthood)
• Patent ductus arteriosus
  
  • The three forms of acyanotic congenital heart disease

Question 4

Why doesn’t VSD have fixed split S2?

Answer 4

Think about it this way:

An ASD allows for an increase in RV preload

A VSD does not increase RV preload by as much since the AV valve has closed and precludes the RV from filling through the pulmonary vein by way of the LA

Question 5

You close an ASD with ___.

You close a VSD with ___.

Answer 5

You close an ASD with a device (interventional radiology).

You close a VSD with surgery.

Question 6

Tetralogy of Fallot is a ___ associated with ___.

Transposition of the great vessels is a ___ associated with ___.

Answer 6

Tetralogy of Fallot is an endocardial cushion defect associated with Down syndrome.

Transposition of the great vessels is a failure of embryologic heart twisting associated with diabetes mellitus (not gestational).

Question 7

TET spell

Answer 7

Kid who is blue and then pinks up when he squats

Pathognomonic for tetralogy of Fallot

Question 8

Claudication in a child is highly suggestive of. . .

Answer 8

. . . coarctation of the aorta

Question 9

Hemoglobin A2

Answer 9

Alpha2 Delta2

Found at low levels in normal adult human blood

Question 10

Embryonic hemoglobin

Answer 10

• Four types:
  
  1. Hb Gower I: ζ₂ε₂
  2. Hb Gower II: α₂ε₂
  3. Hb Portland I: ζ₂γ₂
  4. Hb Portland II: ζ₂β₂
• The Gower forms are the main ones produce in the yolk sac blood islands during embryonic development
• The Portland forms are more scarce and unstable, present at only small amounts during embryonic and fetal development

Question 11

A patient with sickle cell disease is expected to have a ___ creatinine

Answer 11

A patient with sickle cell disease is expected to have a low creatinine

This is due to the hyperfiltration that occurs in the early stages of sickle cell disease due to episodic microvascular renal obstruction from sickled cells, particularly in the medulla.

If a patient with sickle cell disease has a high-normal creatinine, it may indicate an AKI

Question 12

A patient with sickle cell disease is much more likely to have __ gallstones

Answer 12

A patient with sickle cell disease is much more likely to have pigmented gallstones

Question 13

What labs do you probably want baselines for in your sickle cell patients?

Answer 13

• Bili
• Hgb
• Retic count
• LDH
• Cr

Question 14

Deferoxamine

Answer 14

Strong chelator of iron and aluminum

Given to patients with iron overload from chronic transfusions, such as sickle cell or thalassemia major patients

Question 15

Transfusing 1 unit of red cells is roughly equivalent to having ___ worth of iron supplements

Answer 15

Transfusing 1 unit of red cells is roughly equivalent to having 1 years worth worth of iron supplements

So, if someone is getting transfused, they should NOT take supplemental iron

Question 16

For all intents and purposes, you should assume that any patient with sickle cell disease has no ___.

Answer 16

For all intents and purposes, you should assume that any patient with sickle cell disease has no spleen.

Question 17

Penicillin prophylaxis in sickle cell disease

Answer 17

Given from birth to age 5 due to poor splenic function

Some may need it until adulthood. They will also need full pneumococcal vaccination (13-valent and 23-valent).

Question 18

How to think about osteomyelitis etiologies and sickle cell

Answer 18

Someone with sickle cell who gets osteomyelitis is still most likely to have Staph aureus, just like everybody else. S. aureus is just the most common cause of osteomyelitis in everyone, far and away. Salmonella is the second most common cause in those with sickle cell disease.

However, if someone presents with Salmonella osteomyelitis, you should ask yourself if they have sickle cell disease. Only people with sickle cell disease get Salmonella osteomyelitis. But, not every sickle celler with osteomyelitis has Salmonella.

Question 19

Managing avascular necrosis of bone in sickle cell patients

Answer 19

• Often will involve the hip
• Conservative management for 4-6 months (crutches, NSAIDs) is the approach of choice
  
  • If no improvement, go to surgery

Question 20

Indications for exchange transfusion in sickle cell disease

Answer 20

• Stroke
• Acute chest (chest pain, dyspnea,lung infiltrate)
• +/- Priapism (try drainage of penis first)

Question 21

Treating sickle cell crisis

Answer 21

• Exchange transfusion emergently if indicated (acute chest, stroke, +/- priapism)
• Otherwise (most cases):
  
  • IV fluids
  • Oxygen
  • Pain control
• If evidence of infection, treat appropriately
• Follow-up with psychosocial stressors if presenting in crisis with normal labs

Question 22

Hb SC disease

Answer 22

Low Hb, but no or extremely rare sickle cell crises

Question 23

Hb Sβ⁺

Answer 23

• One copy S, one β⁺ (β with slightly lower expression)
• Mild form of SS disease

Question 24

Hb Sβ⁰

Answer 24

• One copy Hb S, one absent β allele
• Most severe form of SS disease

Question 25

Who should get PGE1 therapy? (congenital heart disease)

Answer 25

* **All *_unstable_* infants with suspected CHD of any etiology**

Question 26

Cyanosis correlates to. . .

Answer 26

. . . **the absolute concentration of deoxygenated hemoglobin (~5 g/dL)**

Question 27

Initial workup of a cyanotic newborn

Answer 27

* Goal is to determine whther the goal is cardiac or non-cardiac in origin * Workup includes: * CXR * EKG * Hyperoxia test (FiO₂)

Question 28

When does rib notching appear on CXR for patients with coarctation of the aorta?

Answer 28

Beyond age 5 it becomes reliable

Question 29

PFO treatment

Answer 29

None unless there is ever evidence of paradoxical embolism

Question 30

VSD murmurs

Answer 30

* **Holosystolic at L sternal border** * SOMETIMES an **accompanying diastolic murmur at apex** due to high flow through mitral valve

Question 31

Tricuspid atresia

Answer 31

* Type of cyanotic congenital heart disease * Will present as soon as ductus arteriosus begins to close (first 4 days of life) * LVH will usually be present * Treat w/ PGE1 as bridge to surgery

Question 32

Patients with a VSD and slow progression of Eisenmenger syndrome may present with ___ found incidentally on labs taken for another purpose

Answer 32

Patients with a VSD and slow progression of Eisenmenger syndrome may present with **polycythemia** found incidentally on labs taken for another purpose

Question 33

When considering whether indomethacin might be helpful for suspected PDA, you should take into account. . .

Answer 33

The **total age gestational and post-gestational age** of the child If the child is **premature**, **indomethacin** is likely to succeed. If the child is **term** and is past the first few days of life, **surgery** will likely be required.

Question 34

Primary and secondary prevention of rheumatic fever

Answer 34

* **Primary prevention:** Prompt treatment of Streptococcus pyogenes pharyngitis (with penicillins) * **Secondary prevention:** Intramuscular penicillin G benzathine OR oral macrolides monthly * If no carditis, for 5 years or until age 21 * If carditis, for 10 years or until age 21 * If carditis and permanent valve damage, for 10 years or until age 40

Question 35

Acute treatment of rheumatic fever

Answer 35

**Antibiotics** (penicillin V usually sufficient) and **NSAIDs** (aspirin preferred for adults, but ibuprofen or naproxen for kids)

Question 36

How long after streptococcal pharyngitis does rheumatic fever tend to set in?

Answer 36

2-4 weeks following pharyngitis

Question 37

Best initial test for endocarditis

Answer 37

Obtain 3 sets of blood cultures

Question 38

Treatment for acute re-entrant tachycardia of WPW syndrome

Answer 38

Procainamide

Question 39

Duke criteria

Answer 39

Question 40

Therapies for HOCM

Answer 40

* First-line: Beta blockers * Second-line: NDHP CCBs * Severe disease: * Characterized by dyspnea and chest pain (NYHA III-IV), repeated exertional syncope or presyncope. * Treat w/ surgical septal myectomy. If poor surgical candidate, dual chamber pacemaker may be considered. In end-stage obstructive disease, heart transplant may be only option.

Question 41

First-line for congenital long QT syndrome

Answer 41

beta blockers

Question 42

Howell-Jolly bodies

Answer 42

Red cells with nuclear remnants. Seen in patients with asplenia or poor spleen function (as in sickle cell, for example)

Question 43

Renal pathophysiology in patients with sickle cell trait

Answer 43

* Associated with decreased ability to concentrate urine (**hyposthenuria**) and with **renal papillary necrosis** * Hematuria associated with the above is a common finding * Also higher risk of **CKD, UTIs,** and **renal medullary carcinoma**

Question 44

Most frequent cause of priapism in children and young teens

Answer 44

Sickle cell disease

Question 45

Diamond Blackfan Anemia

Answer 45

* Congenital syndrome of **macrocytic anemia** and **short stature,** **webbed neck,** low set ears, **small jaw,** and **triphalangeal thumbs.** * Anemia is usually isolated (no leukopenia or thrombocytopenia) and VERY macrocytic (\>120s, more so than megaloblastic anemia). There will be no multilobular neutrophils on smear.

Question 46

Fanconi anemia

Answer 46

* Autosomal recessive defect in crosslink repair * Wide variety of manifestations * Often with **pancytopenia, cafe-au-lait spots, microcephaly, strabismus, horseshoe kidney** * Predisposition to developing **leukemias** and **myeloproliferative disorders at a young age**

Question 47

Drugs that may cause aplastic anemia

Answer 47

* Carbamazepine * Methimazole * Prophylthiouracil * NSAIDs * Cytostatic drugs * Chloramphenicol

Question 48

Normal ___ has a high NPV against iron deficiency anemia

Answer 48

Normal **RDW** has a high NPV against iron deficiency anemia

Question 49

Hemoglobin Barts

Answer 49

γ₄ Seen in alpha thalassemia. Levels are highest in complete alpha thalassemia and less so in the less severe forms of alpha thalassemia.

Question 50

Characteristic findings of apslastic anemia vs myelofibrosis on BM biopsy

Answer 50

* Aplastic anemia: Few progenitor cells, lots of fate * Myelofibrosis: Few progenitor cells, lots of collagen

Question 51

Sepsis in a sickle cell patient

Answer 51

Most commonly S. pneumoniae, E. coli, Salmonella, or P. aeruginosa Treat w/ ceftriaxone

Question 52

When is exchange transfusion indicated in sickle cell patients?

Answer 52

1. Acute chest syndrome (chest pain, respiratory difficulty, infiltrate in CXR) 2. Multi-organ failure

Question 53

Differentiating TTP and HUS

Answer 53

TTP presents in adults and is more likely to have a neurologic component HUS presents in kids (usually following diarrhea) and may be due to shiga toxin or complement activation, less likely to have a neurologic component.

Question 54

When do you start a pediatric patient on hemodialysis for AKI?

Answer 54

When significant acidosis is present in context of oliguria

Question 55

Therapy for HUS

Answer 55

* DO NOT give abx or antimotility agents * Dialysis needed in up to 50% of patients * Plasma exchange therapy is for refractory cases * Eculizumab if aHUS is suspected * Report the case -- HUS following diarrhea is a nationally notifiable condition

Question 56

Diagnosis of malaria

Answer 56

Thick and thin blood smears Thick: initial test to detect parasites Thin: Confirmation and speciation of parasites

Question 57

G6PD hemolysis often sets in ___ days following exposure to a trigger

Answer 57

G6PD hemolysis often sets in **2-3** days following exposure to a trigger

Question 58

Diagram of congenital platelet defects

Answer 58

Question 59

Patients with hereditary spherocytosis are at increased risk for \_\_\_. This is often how they present -- their compensated anemia becomes decompensated due to \_\_\_.

Answer 59

Patients with hereditary spherocytosis are at increased risk for **folate deficiency**. This is often how they present -- their compensated anemia becomes decompensated due to **superimposed megaloblastic anemia**. They may also have **glossitis, cheilitis, and dysphagia** when they come in secondary to their folate deficiency.

Question 60

HUS vs aHUS vs TTP

Answer 60

* HUS Triad: Acute renal failure, MAHA, thrombocytopenia *in the setting of **recent dysentery*** and ***without fever*, in children** * aHUS Pentad: **Prominent a****cute renal failure,**MAHA, thrombocytopenia, fever, and *sometimes* neurologic symptoms,**in adults without Hx dysentery** * TTP Pentad: *Sometimes* acute renal failure, MAHA, thrombocytopenia, fever, and **prominent** **neurologic symptoms, in adults without Hx dysentery** * Neurologic symptoms = AMS

Question 61

Etiologies of aHUS

Answer 61

* Congenital: Complement defect * Acquired: Anti-complement factor H antibody

Question 62

Quick takeaways for differentiating HUS, aHUS, and TTP

Answer 62

* HUS: Dysentery in Hx, may be afebrile * aHUS: No dysentery, good ADAMTS13 activity (\>10%), renal failure most prominent * TTP: No dysentery, bad ADAMTS13 activity (\<10%), altered mental status most prominent

Question 63

Two uses for eculizumab

Answer 63

**Eculizumab STOPS complement activity** So, it is used in: **1) aHUS** **2) PNH**

Question 64

Treatment of TTP

Answer 64

Any case of TTP IS AN EMERGENCY Treat with **plasmaphoresis** with **FFP** and **cryosupernatant** -- DO NOT GIVE cryoprecipitate, this will cause a DIC-like picture