1. Chronic NBNB vomiting (w/ weight loss) in an infant:
--Refuses food: likely GERD (esp younger than 3-4 months) since kids’ abdominal/diaphragm muscles are weak and can’t keep food down. At >3-4 months, think other causes. An inflammatory malabsorption (esp with diarrhea), intussuception (esp with blood in stool

--Doesn’t refuse food: think obstruction vs milk allergy.  In a neonate or young infant, think congenital obstruction, in an older kid, think constipation. R/o with abd x-ray to look for fecal impaction, u/s to look for pyloric stenosis. Think cow’s milk allergy if the kid has recently been weaned from breast milk (unless the mom drank a ton of cow’s milk, there will have been little cow milk protein in her milk). Change to very hydrolyzed formula (nutramigen) and see if it resolves. 

2. Bartter’s syndrome (NKCC2 R mutation): it’s like they’re on Lasix all the time. Shutting down the receptor means greater volume of more dilute urine- you can’t remove salt at TALH, so you can’t remove water in collecting ducts. You lose the cycling of K (K comes in through NKCC, goes out through K channel), so you lose the net positive charge in kidney tubule lumen, which is the driving force for the reabsorption of divalent cations. This leads to kidney wasting of Ca & Mg. You don’t waste Na, since your kidneys ramp up reabsorption of Na at the DCT and CD, at the price of losing K and H. Additionally, the loss of Cl at NKCC means that your body will also reclaim bicarbonate to make up the charge balance, worsening the alkalosis. Treatment is to figure out which electrolytes are low, and to replenish.

3. Gittleman’s syndrome: NaCl R mutation: its like you’re on a thiazide diuretic all the time. Gordon’s syndrome: mutation in the regulation of NaCl, leading to increased expression, the opposite of being on a thiazide: you retain water and salt, and become hypertensive. Tx with a thiazide diuretic (now isn’t that convenient?

4. Lasix tolerance: starting Lasix diureses great at first, but over time the kidneys compensate. I.e. upregulation of Na-Cl receptors in the DCT. This compensatory process is driven in part by hypochloremia. Replenishing chloride will often cause diuresis to resume, as will adding a thiazide diuretic (which will possibly worsen the hypochloremia

5. Complete asthma history:

--Age of dx, +eczema/allergies, previous classification: symptoms/week (wheezing, coughing, SOB), nighttime symptoms/month (waking up to cough

--History: number of ER/hospital visits in the last year/lifetime. Lifetime ICU/intubation/bipap. How often do you miss school/work or does asthma interfere with activities.

--Medication: rescue inhaler/nebs, controller medicine, allergy medicine. Ask: how often are each used/using a spacer?

--Triggers: smoke, weather, exercise, pets, scents, mold, colds.

--Family Hx of atopy

6. Rolandic epilepsy: a benign epilepsy of childhood, peak incidence at 7-9 years of age, usually resolves by 13 on its own. Associated with centro-temporal spikes on EEG. A partial simple epilepsy that involves the face muscles, occurs generally at night (can be missed). Can generalize to tonic-clonic seizures. Generally not managed with AED: meds decrease generalization, but don’t decrease incidence of partial seizures. 

7. DDx of hemoptysis in a child:

--Infectious: TB, lung abscess (strep/staph), bronchiectasis (CF)

--Mechanical: foreign object, tracheal erosion from suctioning someone on a ventilator, trauma

--Rheum: Wegener’s (GPA), goodpasture, sarcoidosis, churg-strauss

--Vascular/Blood: AVM, PE

--Other: diffuse alveolar damage (precursor to ARDS), malignancy

--Cardiac: diastolic failure => backup of blood in lungs => pulmonary hypertension & blood leaking into alveoli. Think mitral stenosis, diastolic heart failure (amyloid/sarcoid), pulmonary hypertension. 

--Differentiate from hematemesis: pH (hematemesis will be acidic, hemoptysis will be alkaline), appearance (hemoptysis will be frothy) 

8. Babies fed exclusively goat's milk or who are vegan/fed with breastmilk from a vegan woman can suffer from B12 or folate deficiency and end up with megaloblastic anemia, or worse, methylmalonic acidemia --- inability to convert MMA to succinyl-CoA, MMA accumulates in myelin and can lead to seizures, neurodevelopmental consequences. 

9. The only indications for soy formula are galactosemia, or strict vegetarian diet. Babies that are allergic to milk have a 10-15% cross-allergy with soy, so it's better to put them on hydrolyzed cow's milk formula. 

10. Review of hypersensitivities: 

--type 1: anaphylaxis, IgE mediated

--type 2: autoantibodies against fixed structure (i.e. basement membrane-- goodpastures)

--type 3: autoantibodies against non-fixed antigen (i..e. IgM against IgG)

--type 4: cell-mediated, delayed.