HemeOnc

Question 1

Types and breakdown of Hgb in newborn blood

(December 2021)

Answer 1

HbF (fetal, α2/γ2) and HbA (adult, α2/β2) with the latter ~6-40% depending on time relative to transition from predominantly fetal to adult Hgb

Question 2

HbSS disease - what is it from Hgb standpoint and how do pRBC transfusions relative to newborn screen collection affect screening results

(December 2021)

Answer 2

Point mutation in β-globin gene where none are normal, so they lack HbA (α2/β2) and only have HbF and HbS. If transfused pre-PKU draw then could pick up HbA and be falsely negative. Recommend repeat 90 days post-transfusion or if collected <33 WGA, because preterm infants have less HbA inherently.

Question 3

Maternal medications that can increase the risk of early VKDB?

(December 2021)

Answer 3

Anticonvulsants (ie phenobarbital, phenytoin, carbamazepine), anticoagulants, and anti-TB drugs

Question 4

Time of onset and details of early v classic v late VKDB?

(December 2021)

Answer 4

-Early: first 24h; often severe & life-threatening. 25% ICH, cephalohematoma, subgaleal, intra-thoracic, intra-abdominal, GI tract, umbilical cord

-Classic: 2-7d; umbilical stump bruising/bleeding, circ site, GI tract, nose, rarely ICH

-Late: 2 wks- 6 mos; 30-60% ICH; generally exclusively breastfed infants who did not receive IM Vitamin K or malabsorptive disorders. Skin/GI tract bleeds also possible. Of note, oral VK helps with early and classic but not late onset VKDB

Question 5

Diagnostic criteria for VKDB

(December 2021)

Answer 5

(i) PT greater than or equal to 4x control (ii) normal or increased platelets (iii) normal fibrinogen and degradation products (iv) normalization of PT after VK administration

Question 6

Types of exchange transfusion, amount of blood volume replaced and % blood volume exchanged

(December 2021)

Answer 6

-partial volume: aims to modulate infant’s Hct while maintaining their blood volume ie normal saline for polycythemia with hyper viscosity syndrome

-single volume: replaces ~80 mL/kg of blood with ~60% of blood volume being exchanged. ?Maybe fewer side effects but not recommended over double due to risk:benefit re: reducing kernicterus

-double volume: replaces ~160 mL/kg of blood with ~85% of blood volume being exchanged.

Question 7

Potential complications from exchange transfusion

(December 2021)

Answer 7

-hypotension, metabolic acidosis
-A/Bs
-arrhythmias
-hypocalcemia, hyperkalemia
-hypoglycemia
-NEC
-coagulopathy
-thrombocytopenia
-infection, air embolism

Question 8

What is the most common germ cell tumor (GCT) in neonates? Primary treatment? Monitoring post-treatment?

(March 2022)

Answer 8

-teratoma
-postnatal surgical resection in any site
-Recurrence is low even in tumors with yolk sac or malignant components
-monitor serially with exam, imaging, and serum AFP levels and in rare case of recurrence then cisplatin or carboplatin-based chemotherapy is used