1. Child presents with fatigue, easy bruising. CBC comes up with a WBC of 100K, 98% blasts, hb 5 and platelets 5k. You suspect ALL.
Workup:
-BMP: ALL kids often have high K/Phos (since cells are lysing) and low Ca (since phos is high).
---Tx hyperK: shift K intracellularly (albuterol neb, insulin+glucose, bicarb if they're acidotic) and excrete it (lasix, kayexylate). Give kayexylate PO, not rectally, b/c kids with ALL are often effectively neutropenic. Even if their counts are high, their neutrophils suck/are blasts.
---To prevent Ca-Phos crystals, do not supplement Ca unless they are symptomatic, aim for a Ca*Phos<60, and do not alkalinize beyond 8.
---Keep an eye on BUN/Cr since crystal precipitation (urate/ca-phos) and tumor invasion/compression of GU system can cause renal failure.
-Uric Acid & LDH: both will give you a sense of tumor burden and of tumor lysis syndrome. To prevent uric acid crystals from forming, alkalinize slightly with bicarbonate.
-CXR: look for mediastinal mass
-Immunophenotyping: figure out if its acute vs chronic, lymphocytes vs monocytes, T-cell vs B-cell.
-Coag studies: PT/PTT & d-dimer/fibrinogen to r/o DIC
 2. Preventing tumor lysis syndrome: give allopurinol with chemotherapy. If someone is symptomatic, you can give a uricase, which directly breaks down urate. However, it is very expensive and thus not indicated for broad use in everyone. Steroids can help lower tumor burden in a slightly slower, more controlled way.
3. DDx of anterior mediastinal mass: lymphoma (hogkins/non-hodgkins), T-cell ALL (esp in teenager), thymoma, germ cell, thyroid. Posterior mediastinal mass: neuroblastoma (check urine/serum VMA/HVA)
4. It's hard/potentially dangerous to sedate someone with a mediastinal mass: they often have diminished respiratory capacity; in sedation, you lose negative intrathoracic pressure and respiratory muscle tone, further reducing ease of breathing (and also of mechanical ventilation). This can cause the mass to fall onto the mediastinum and compress either the respiratory structures (even a trach wouldn't help you then) or the major vessels, leading to a precipitous fall in preload and then to cardiac arrest.If you're going to sedate someone with a mediastinal mass, load them up with IV fluids beforehand and have an ECMO on standby.
5. Hyperleukocytosis can lead to leukostasis (sludging of WBC) esp if white count is in the hundreds of thousands. Sludging of capillaries in lungs (leading to respiratory insufficiency) and brain (leading to neurological deficits ranging from fatigue or behavior changes to ataxia, seizures, stroke) are most concerning. Kidneys can also take a hit.
6. In terms of leukostasis, myeloblasts are the worst because they are big, least deformable, and trap plasma between them. Lymphoblasts are slightly better (i.e. you need a higher "leukocrit" to have the same clinical sequelae) and mature lymphocytes are the best. The body will often decrease the hematocrit in an attempt to reduce blood viscosity-- thus, in someone with leukostasis, do not transfuse unless absolutely necessary, even if their hb is very low.
7. Spinal cord compression can happen in neuroblastomas, adrenal tumors, spinal  osteosarcoma. First sx is pain, then paresthesias, final loss is bladder/bowel. Tx is with high-dose steroids and laminectomy.
8. Any temperature over 100.4 F/38 C in a newborn (measured rectally) requires emergent hospitalization for at least 48 hours, with blood and urine cultures and a LP (neonate BBB is less developed). Most common bugs causing infection in a neonate: listeria, e.coli/GNR, enterococcus, GBS. (Slightly older neonate: HiB, S.pneumo, Neisseria). Treat empirically with Amp+Gent, or Amp+Cefotaxime in places with widespread gent resistance. Amp covers listeria, e.coli and other easy GNR (hib, kleb, proteus etc), and easy gram pos like strep and non-b-lactamase-staph. Cefotaxime is a 3rd generation cephalosporin like ceftriaxone, and has excellent gram negative coverage-- hits everything except pseudomonas.
9. Constipation is a common occurrence in kids. Treat with stool softeners first (PEG, like miralax): titrate up the dose if its not working at first. Go to stimulant laxatives (like senna) only after the stool softeners have failed. If you do give a stimulant, you must also concomitantly give a stool softener.
10. Treat a penicillin-induced allergic rash with benadryl (children: 1-2 mg/kg q6 hours)