UWorld Peds 9 PDF

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Renal/Urinary/Electrolytes 4018/4059: Minimal Change Disease  Most common cause of nephrotic syndrome in children under age 10 (very rare in teenage/adult years)  Presentation: fatigue, edema (orbital, facial, genital, sacral, LE; often mild in morning progressing to prominent through the day), & hypoalbuminemia  Pathophysiology: T-cell damage to podocytes of glomerular basement membrane (allows protein permeability). Often idiopathic. o Primary (idiopathic) is the most common cause o Secondary causes: Hodgkin Lymphoma (Reed-Sternburg Cells)/Thymoma/T-cell leukemia  Labs: Urine dipstick (shows protein), 24hr urine collection/random urinalysis (nephrotic range proteinuria, no hematuria), low serum bicarbonate, high serum Cl Biopsy: indicated for children >10yr or if not responding to empiric steroids o Light: no pathologic changes noted o Immuno: normal glomeruli without deposition of antibodies o Electron: diffuse effacement of podocyte foot processes  Dx: presentation + labs; biopsy only indicated in some situations  Tx: empiric steroid administration (extremely steroid responsive) o Further workup needed for those not responding to steroids 4828: Renal Tubular Acidosis  Presentation: o Infants/Young children: failure to thrive (acidic environment = poor cell division), poor weight gain, normal anion gap metabolic acidosis + hyperchloremia o Older children/Adults: recurrent calculi, muscle weakness, bone pain, myalgias  Nephrocalcinosis causing polyuria (failure of nephron)  Normal anion gap metabolic acidosis + hyperchloremia  Pathophysiology: genetic disorders that make the kidneys unable to maintain normal acid-base balance causing acidification of the blood/serum (acidosis)  Subtypes o Type 1 (Distal): poor Hydrogen secretion into urine causing retention of H+ ions  Metabolic acidosis; more alkaline urine (pH >5.5); low-normal serum K+  (+)urine anion gap (urine Na+ + urine K+ - urine Cl-)  Often associated with nephrolithiasis/family Hx of nephrolithiasis (genetic disorders)  Medications or autoimmune etiology are also possible  Tx: low dose oral alkaline solutions o Type 2 (Proximal): poor HCO3- resorption causing wasting in urine  Metabolic acidosis; normal acidic urine (pH 5yr o Normal until age 5; girls often potty trained earlier than boys o Primary: child never achieved “dryness” o Secondary: child achieved “dryness” for >6 months with re-emergence of bedwetting  Genetic – strong genetic link for familial enuresis on chromosome 13  Psychologic stress – behavior regression/mood lability/change to environment (birth of a new child, new home, first time at school, etc.)  UTI – dysuria, hesitancy, urgency, abdominal/flank pain  Diabetes mellitus – polyuria, polydipsia, polyphagia, weight loss, lethargy, candidiasis  Diabetes insipidus – polyuria, polydipsia, large volume dilute urine (rare in children!)  Obstructive sleep apnea – snoring, dry mouth, fatigue, hyperactivity, irritability  Labs: urinalysis, further studies based on suspected etiology  Imaging: ultrasound/other imaging if daytime symptoms or Hx of recurrent UTI  Dx: clinical presentation  Tx: o 1st line: Non-pharmacologic behavioral interventions  Avoid sugary drinks/caffeine before bed, engage in regular daytime voiding/voiding just before bed, minimize all fluid intake near bedtime, start a reward system for dry nights  Enuresis alarm to require regular bladder filling/voiding to “train” the bladder (3-5mo of therapy); best long-term outcomes o 2nd line: Demopressin (ADH analogue) +/- oxybutynin (anti-cholinergic) to decrease urine output and promote bladder retention of urine  High rate of relapse with stopping medications & hyponatremia concerns rd o 3 line: TCAs (imipramine is classic; concern for suicidality/cardiotoxicity) 2233: Alport’s Syndrome  Presentation: classic triad of hematuria/proteinuria, sensoneurial deafness, and familial kidney failure o May feature vision abnormalities but this is less common (25%)  Pathophysiology: mutation of a-5 chain of type IV collagen affecting basement membranes

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o Kidney (glomerular BM); Ear (cochlear BM); Eye (lens/retina BM) o X-linked dominant: males (full presentation) and females (isolated hematuria) Biopsy: often indicated for nephritic/nephrotic syndrome in children over age 10yr o Light: may be normal (early) or “basket weaving” if late stage o Immuno: nothing detected o Electron: “basket weaving” alternating thick and thin capillary loops with GBM splitting Other things that might look like Alport’s o Thin basement membrane disease: AD mutation of a-3/a-4 chains of Type IV collagen; often results with benign hematuria and a “thin” basement membrane (1/2 normal thickness throughout) o Anti-GBM disease: autoantibody to the “non-collagenous” domain of a-3 chain of Type IV collagen; Biopsy shows linear IgG deposits on the GBM characteristically; essentially Goodpasture syndrome but only of the kidney o Benign recurrent hematuria: Renal biopsy shows totally normal architecture and problem likely will resolve on it’s own.

3692/4005/4196: Urinary Tract Infection (UTI)  Risk Factors: uncircumsized male 39C (102.2 F) in any child >> Staph. Saprophyticus > other bugs  Labs: Serum BUN/Cr (estimate renal function); urine dipstick (qualitative urine assessment); urinalysis (quantitative urine assessment); urine culture (test for/ID bacteria & susceptibilities) o Mid-stream clean-catch is appropriate in children/adults not in diapers o Straight Catheterization for urine sample is necessary in children in diapers, as the presence of feces/skin flora in the diaper make for a high chance for sample contamination o Urinanlysis may show (+)blood/RBCs/leukocyte esterase/nitrites/bacteria/WBCs  Imaging: o Indications for Renal/Bladder Ultrasound (checks urologic abnormalities  increased UTI risk)  Any infant 3wk)  Pathophysiology: defective integrins on leukocyte surface stopping normal adhesion needed for extravasation, stopping migration of WBCs to areas of inflammation o Inflammation still occurs but no early WBC neutrophils to direct inflammation  Labs: CBC (marked neutrophilia/lymphocytosis); analysis of wound drainage  Dx: presentation + labs  Tx: ??? 3602/3993: Selective IgA deficiency  Presentation: often asymptomatic but classically recurrent sinopulmonary/GI infections due to impaired immunologic IgA barrier on mucosal surfaces o Importantly any blood transfusion will cause anaphylaxis in these patients, as they will mount an immune response to IgA present in donor blood. Thus any blood products of a patient with this disease must be washed for IgA and patients must wear information bracelets.

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o In Celiac’s Disease: Selective IgA deficiency may actually mask the IgA autoimmune bodies, thus is suspicion is high, but IgA is negative  check total IgA for deficiency and check Anti-IgG antibodies Dx: Low IgA, normal IgM/IgG, normal B-cells/T-cells +/- low IgG2/IgG4 selective deficiency Tx: supportive care with medical alert bracelet

4847: Wiskott-Aldrich Syndrome  Presentation: eczema (dry/scaly rashing), microthrombocytopenia (low platelets with small platelets), petechiae/purpura/severe bleeding (intracranial, GI), and recurrent infections (B/T-cell dysfunction)  Pathophysiology: X-linked recessive mutation on WAS protein gene; causes impaired cytoskeleton remodeling in hematopeotic cells, screwing up their response to the body’s environment o Dysfunction in leukocytes  B/T-cell poor migration & immune synapse function o Dysfunction in platelets  tiny/few platelets cripples primary hemostasis  Labs: CBC (thrombocytopenia)  Smear: thrombocytopenia with small platelets  Dx: presentation + peripheral blood smear  Tx: hematopoietic stem cell transplant 3545: DiGeorge Syndrome  Presentation: developmental delay, dysmorphic facies (cleft palate, short palpebral fissures, small chin, ear malformation), parathyroid aplasia/hypoplasia (hypocalcemia), thymic aplasia (T-cell dysfunction & lymphopenia), congenital heart disease (truncus arteriosus >> VSD, ToF, aortic arch interruption) o Complications: tetany/seizures/arrhythmias (severe hypocalcemia), bacterial/viral/fungal infections (T-cell/B-cell dysfunction)  Pathophysiology: sporadic or AD 22q11.2 microdeletion causing abnormal development of the the pharyngeal pouches  abnormal facial, neck, and mediastinal development  Labs: serum calcium (hypocalcemia), CBC (low T-cells/lymphopenia)  Imaging: echocardiography (rule out cardiac defects)  Dx: FISH study showing microdeletion  Tx: aggressive Ca2+ repletion; fixing any abnormalities; vaccination against disease  Lookalikes: Velocardiofacial syndrome (22q11.1 microdeletion; “Incomplete DiGeorge syndrome) – developmental delay/hypotonia, dysmorphic facies (cleft palate, wide/prominent nose with square nasal root, short chin, fish-shaped mouth), & congenital heart disease (VSD, right-sided aortic arch); no parathyroid or thymus problems Other Immunodeficiency syndromes mentioned in this section  IgG Subclass Deficiency – recurrent sinopulmonary infections; low-normal IgG with normal IgM/IgA  Job’s Syndrome (hyper IgE syndrome) – abnormal Faces, cold staph Abscesses (no inflammation), retained 1o Teeth, high IgE, Dermatologic problems (eczema)  FATED mnemonic  Chediak-Higashi syndrome – failure of lysosomal trafficking enzymes (giant neutrophil blue-grey granules & neutropenia) causing recurrent infections, ocular albinism (bright blue eyes/photophobia), dermatologic albinism, hair with silver streaks  Transient Hypoglobulinemia of Infancy – IgG levels will dip in newborns around 6mo (mom’s passive immunization wears off); IgA/IgM/B-cells/T-cells are all normal; typically resolves by 12mo

General Principles 2433/4199/4822/4823/4874/7741: Normal Developmental Milestones Age Gross Motor Fine Motor Language Social/Cognitive 2mo Lifts head/chest Hands unfisted Alerts to voice & Social smile, when prone 50%; tracks past sounds, coos recognizes midline parents 4mo Sits with support; Hands mostly Laughs; turns to Enjoys looking beings rolling open; reaches voice around midline Stranger anxiety Responds to 6mo Begins to sit with Transfers objects hand-to-hand; names; babbles propped hands raking grasp mixing vowels & (unsupported at consonants 7mo) 9mo Pulls to stand; 3-finger pincer Says “mama” Waves “bye” & cruises grasp; hold “dada” plays Pat-a-Cake bottle/cup 12m Stands; walks first 2-finger pincer Separation 1st words (not o independent grasp ‘mama’ or ‘dada’) anxiety; follows 1steps; throws ball step commands & gestures Understands 18m Runs; kicks a ball Tower (2-4 10-25 words; “mine”; plays phrases emerge o cubes); removes pretend alone (“Thank you” clothing “Stop it”); IDs 1 body part Follow 2-step Tower (6 cubes); 50+ words; 2 2yr Scales stairs with commands; copies a line word telegraphic both feet on parallel play; sentences steps; jumps toilet training starts Copies a circle; 3 word sentences; Knows 3yr Scales stairs with age/gender, uses utensils 75% intelligible alternative feet; imaginative play speech ride tricycle Cooperative play 4yr Balance/hops on Copies a square Identifies colors; 1 foot 100% intelligible speech 5yr Skins/walks Copies a triangle; 5 word sentences; Makes friends; backwards prints letters; ties counts to 10 completes toilet training shoelaces; dresses/bathes independently

Red Flags Fails to alert; irritability; no social smile; early rolling (hypotonic) Poor head control, no laugh, no visual threat No rolling; head lag

W-sitting (hypotonia), Scissoring (hypertonia), primitive reflexes Unable to localize sounds; no protective reflexes Persistent Toe walking (hypertonia)

Poor transitions, lack of social interactions

Echolalia (autism); extended family fails to understand speech

Strangers fail to understand speech

3418: Intraosseous IV access (IO) at the proximal tibia is a common site for venous access when peripheral lines are difficult to start in children (adults not so much!)  Easier to start (less risk) than a central line  Away from the sternum/chest if cardiac resuscitation is needed simultaneously

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Contraindications: active infection in the area, fracture, previous unsuccessful IO attempts, severe bone fragility (osteogenesis imperfecta, etc.)

7726: Evaluating Neonatal Hydration/Weight Loss  Presentation: decreased wet diapers, decreased tearing, sunken fontanelles, dry mucous membranes, decreased skin turgor, delayed capillary refill o [# of wet diapers/day = # of days old] in the first week of life o ‘Pink-stain’/’brick-dust’ poop (uric acid crystals) is a sign of mild dehydration in the 1st week  Normally, a child should lose up to 7% of their birthweight in the first 5 days of life (excretion of excess fluids from in-utero & during labor) o Wt loss 7% - assess for sucking failure/lactation failure, daily weightings, & supplement with formula GI 4925: Pediatric Dehydration Assessment & Resuscitation  Children are more susceptible to dehydration due to 1high-frequency gastroenteritis, 2high surface-area to volume ratio (increased insensible losses), and 3possible inability to access fluids or communicate they’re thirsty to their provider  First Step: determine severity o Ideal: regular body weighings (1kg lost = 1L fluid lost); this is near impossible as it’s hard to pinpoint a child’s “well weight” before the start of the illness due to rapid growth o Realistic: clinical history and physical exam  Mild (3-5% loss): Hx of decreased intake/fluid loss but minimal symptoms  Moderate (6-9% loss): decreased skin turgor, dry mucus membranes, tachycardia, irritability, delayed capillary refill (2-3sec), & decreased urine output  Severe (10-15% loss): cool/clammy skin, dry mucous membranes, cracked lips, sunken eyes/fontanelles, tachycardia, lethargy, delayed capillary refill (>3sec), and minimal urine output  Second Step: rehydration therapy o Mild-Moderate: oral rehydration therapy (if tolerated)  The glucose-sodium filled solutions for ORT work on the principle that coupled cotransport for glucose-Na are maintained even with secretory diarrhea, while other Na absorption mechanisms are impaired  It’s important to use drinks specifically targeted at oral rehydration, as their electrolyte profiles are specifically targeted to take advantage of this. Gatorade does NOT meet these qualifications & may act as osmotic diuretics due to high sugar content. o Moderate-Severe: IV fluids with isotonic crystalloids  add dextrose after initial resuscitation  Emergency Phase: 20mL/kg IV bolus with appropriate solution  Repletion Phase: electrolyte repletion over 24 or 48hr if hypernatremic (100-50-20 rule)  +100mL/kg/day – first 10kg body weight  +50mL/kg/day – second 10kg body weight  +20mL/kg/day – each kg above 20kg previously accounted for  Consider adding more if increased insensible losses (respiratory distress or fever)  Rate is determined by the 4-2-1 Rule o +4mL/hr – first 10kg body weight o +2mL/hr – second 10kg body weight o +1mL/hr – each kg above 20kg previously accounted for

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 Ex) 24kg child would get 1000mL + 500mL + 80mL = 1580mL/day @ 64mL/hr Hypotonic should NEVER be used as concerns over electrolyte changes can result in cerebral edema/permanent brain damage/locked-in syndrome

8955: Pediatric Constipation  Presentation: 25mg/dL (exchange transfusion)

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Breastfeeding Failure Jaundice o Presentation: jaundice within first week of life, dehydration, inadequate stooling (dark/sticky meconium should transition to yellow-green/seedy stools within first week) o Pathophysiology: inadequate breastfeeding leads to dehydration and slowed passage of bilirubin-laden meconium in the gut. Bili in stagnant stool gets more time to be re-absorbed, leading to heightened enterohepatic circulation  unconjugated bilirubinemia  Mom: poor milk supply, cracked/clogged nipples, engorgement, infrequent feeds  Child: poor latching, ineffective sucking, falling asleep with feeds o Labs: unconjugated hyperbilirubinemia o Dx: presentation o Tx: identification of lactation failure with specific plan to address it (some common ones below)  Increase Feed Frequency: neonates are fed 8-12 times/day (every 2-3hr)  Increase Feed Time: feeds should last approximately 10-20min/per breast during the first month of life  Maintain Mom Hydration: if mom is dried out, milk may be produced in lower quantity  Formula Supplementation: if above does not work, supplementation may be needed o Follow-up: follow-up after 2 days with H&P, weight, and bilirubin levels to note resolution  If not resolving: phototherapy (>20mg/dL bili) or exchange transfusion (>25 bili)  Even if breast milk is low, do not discontinue breastfeeding as the benefits will be lost. Simply continue and supplement as needed. Breast Milk Jaundice o Presentation: jaundice after the first week of life, adequate hydration/stooling o Pathophysiology: high levels of B-glucuronidase/lipase in mother’s milk causing increased enterohepatic circulation; although not well understood o Labs: unconjugated hyperbilirubinemia o Dx: presentation o Tx: none needed; will resolve between weeks 2-10 of life

2923/2924/2983: Genetic Diseases of Liver Metabolism  Dubin-Johnson syndrome – conjugated bilirubinemia; jaundice with body stressors (illness, pregnancy, OCP use) but otherwise no/minor symptoms (fatigue, abd. pain, weakness) and no hemolysis o More common in Sephardic Jews o Clinically normal aside from reactionary jaundice and black liver (epinephrine metabolites) o Labs: Bilirubin (20-25 mg/dL), normal LFTs, normal coproporphyrin (predominantly Copro I)  Rotor syndrome – Dubin-Johnson syndrome without the black liver  Crigler-Najjar syndrome – autosomal recessive unconjugated bilirubinemia (passes through BBB) o Type 1: significant mental retardation/death; Phototherapy/plasmapheresis can help conjugate the bilirubin to buy time for curative liver transplant o Type 2: fairly benign unconjugated bilirubinemia with jaundice; often asymptomatic, but symptoms (if occuring) can be treated with phenobarbital or clofibrate  Gilbert syndrome – mild unconjugated bilirubinemia triggered by bodily stressors; very similar to C-N syndrome II, difference is in the enzyme defect 2478/2479/4868: Breastmilk & Breastfeeding  Breastmilk is considered the ideal human nutrition source for full-term infants & should be given exclusively for the first 6mo of life as long as child is maintaining normal growth status o Pureed solid foods are introduced at 6mo with continuation of breastmilk until age 1yr  Start with pureed fruits/vegetables  pureed proteins/meats

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 Fruit juice can be started at 6mo, but no more than 4-6oz/day (risk of dental caries!)  Introduction of allergenic foods does NOT decrease allergy development o Cow’s milk introduced at 1yr of age Benefits of Breastmilk for baby o Protein content highest right after birth; consists of 70% whey and 30% casein proteins (Whey protein = easier to digest & promotes gastric emptying) o Aids in digestion (lysozymes) & promotes absorption of nutrients o Aids in passive immunization (contains maternal IgA, lactoferrin) with decreased rates of otitis media, gastroenteritis, URI, UTI, necrotizing enterocolitis, Type I diabetes, childhood cancer, and childhood obesity o Associated with less reflux/colic than traditional formulas Drawbacks of Breastmilk baby o Less phosphorus/calcium (but better absorbed, thus it’s a bit of a wash) o Vitamin D deficient – Vit. D supplementation (400IU/day in the first month of life is mandated with exclusive breast feeding o Iron deficiency – prematuity/maternal iron deficiency can largely predispose child to iron deficiency. Supplementation should occur from [birth – 1yr] if risk factors present  Fe deficiency is the most common nutritional deficiency of infancy!  Switching to cow’s milk before 1yr of age increases risk of this o B12 deficiency – if mom is vegan; recommend supplementation if this is the case Benefits of Breastfeeding for mom o Rapid uterine involution/decreased post-...