Pediatrics COMAT Command Center Pediatrics Shelf Exam Command Center

Neonatal resuscitation follows the NRP algorithmic hierarchy: evaluate term gestation, tone, and crying/breathing. If non-vigorous: warm, dry, stimulate, clear airway if obstructed, and position head in 'sniffing position'. If heart rate < 100 bpm or gasping/apneic: initiate Positive Pressure Ventilation (PPV) with room air (21% O2 for ≥ 35 weeks) at 40–60 breaths/min. If HR remains < 100 bpm after 15 seconds: perform MR. SOPA corrective steps (Mask adjustment, Reposition airway, Suction mouth and nose, Open mouth, Pressure increase, Alternative airway [ETT/LMA]). If HR drops < 60 bpm despite 30 seconds of effective PPV: initiate chest compressions (3:1 compression-to-ventilation ratio, 90 compressions and 30 breaths per minute) and increase supplemental oxygen to 100%. Administer IV/IO Epinephrine (0.02 mg/kg of 0.1 mg/mL) if HR remains < 60 bpm despite compressions.

Routine newborn care within the first hours of life includes: (1) Intramuscular Vitamin K1 (phytonadione 1 mg IM) to prevent Vitamin K Deficiency Bleeding (VKDB, early intracranial and late gastrointestinal hemorrhage from impaired gamma-carboxylation of factors II, VII, IX, X, protein C and S); (2) Topical Erythromycin ophthalmic ointment (0.5%) to prevent ophthalmia neonatorum caused by Neisseria gonorrhoeae (note: erythromycin does NOT prevent Chlamydia trachomatis conjunctivitis, which presents at 5–14 days and requires oral Erythromycin); and (3) Hepatitis B vaccine (add Hepatitis B Immune Globulin [HBIG] within 12 hours if mother is HBsAg-positive or unknown).

Neonatal Jaundice is classified as Pathologic if it appears within the first 24 hours of life, total bilirubin rises > 5 mg/dL/day, exceeds the 95th percentile on the Bhutani nomogram, or direct (conjugated) bilirubin is > 1.0 mg/dL (indicating cholestasis, biliary atresia, or neonatal hepatitis). Jaundice after 24 hours is typically benign: Physiologic Jaundice (peaks at day 3–5 due to transient immaturity of hepatic UDP-glucuronosyltransferase [UGT1A1] and high RBC turnover), Breastfeeding Jaundice (first week of life, dehydration and low caloric intake promoting increased enterohepatic circulation), or Breast Milk Jaundice (starts after day 7, peaks at 2 weeks, caused by beta-glucuronidase and high lipase in breast milk deconjugating intestinal bilirubin). Phototherapy converts unconjugated bilirubin into water-soluble lumirubin excreted in bile and urine without conjugation.

Developmental surveillance tracks four core functional streams: Gross Motor, Fine Motor, Language, and Social/Adaptive. At 2 months: social smile, tracks past midline, lifts head to 45 degrees prone. At 4 months: rolls front-to-back, grasps rattle, laughs, holds head steady. At 6 months: sits unsupported with tripodding, rolls back-to-front, transfers objects hand-to-hand, babbles consonant sounds, stranger anxiety begins. At 9 months: pulls to stand, crawls, pincer grasp (crude 3-finger), plays peek-a-boo, responds to own name, waves 'bye-bye'.

At 12 months (1 year): walks independently or cruises, neat 2-finger pincer grasp, speaks 1–3 specific words ('mama', 'dada'), follows 1-step command with gesture, drinks from a cup. At 18 months: runs, climbs onto chair, builds tower of 3–4 cubes, speaks 10–25 words, uses a spoon. At 2 years (24 months): kicks a ball, walks up and down stairs two feet per step, builds tower of 6 cubes, speaks 2-word phrases ('want milk'), 50% of speech understood by strangers, parallel play.

At 3 years: pedals a tricycle, walks up stairs alternating feet, copies a circle, speaks in 3-word sentences, 75% of speech understood by strangers, dresses with help, group cooperative play. At 4 years: hops on one foot, copies a cross, catches a bounced ball, 100% of speech understood by strangers, tells stories, independent toileting. At 5 years: skips, ties shoes, copies a triangle, prints letters/numbers, counts to 10.

Measles (Rubeola, paramyxovirus) begins with a high prodromal fever accompanied by the classic '3 C's': Cough, Coryza, and Conjunctivitis with photophobia. Pathognomonic Koplik spots (tiny, white-blue grain-of-salt lesions on an erythematous buccal mucosa opposite the lower molars) appear 1–2 days prior to the exanthem. The erythematous maculopapular rash begins at the hairline and face, spreading cephalocaudally down the trunk and extremities, becoming confluent and desquamating. Vitamin A supplementation is mandatory to reduce morbidity and mortality from giant cell pneumonia and blindness. Subacute Sclerosing Panencephalitis (SSPE) is a fatal, late neurodegenerative complication occurring 7–10 years post-infection.

Rubella (German Measles, togavirus) presents with a mild fever, striking tender suboccipital and postauricular lymphadenopathy, and Forchheimer spots (petechiae on the soft palate). A fine pink maculopapular rash spreads rapidly cephalocaudally, clearing from the face as it reaches the trunk. Congenital Rubella Syndrome produces the classic triad: Sensorineural hearing loss, Cataracts, and Cardiac malformations (Patent Ductus Arteriosus [PDA] or peripheral pulmonary stenosis), often accompanied by a 'blueberry muffin' purpuric skin rash from extramedullary hematopoiesis.

Roseola Infantum (Exanthem Subitum, Human Herpesvirus 6 [HHV-6]) classically affects infants aged 6–18 months. It is characterized by 3 to 5 days of exceptionally high fever (> 40°C, often precipitating febrile seizures) in an otherwise well-appearing child. As the fever abruptly defervesces ('breaks'), a faint, rose-pink maculopapular rash appears on the neck and trunk, spreading to the extremities, sparing the face. Erythema Infectiosum (Fifth Disease, Parvovirus B19) presents in school-aged children with bright erythematous facial erythema ('slapped cheek' appearance with circumoral pallor), followed days later by a reticular, lacy, pruritic erythematous rash over the trunk and extremities that waxes and wanes with temperature changes. Parvovirus B19 selectively infects erythrocyte progenitor cells, causing transient aplastic crisis in patients with underlying hemoglobinopathies (sickle cell disease, hereditary spherocytosis) and hydrops fetalis in utero.

Acute Bronchiolitis is the leading cause of hospitalization in infants < 2 years, predominantly caused by Respiratory Syncytial Virus (RSV). Following a 2–3 day prodrome of rhinorrhea and low-grade fever, infants develop tachypnea, subcostal/intercostal retractions, grunting, nasal flaring, and diffuse bilateral expiratory wheezing with fine crackles. Diagnosis is purely clinical; viral PCR swabs, chest X-rays, and blood work are NOT routinely recommended. AAP clinical practice guidelines emphasize supportive care: nasal suctioning, hydration, and supplemental oxygen targeting SpO2 ≥ 90%. Routine administration of bronchodilators (albuterol), epinephrine, and systemic corticosteroids is NOT recommended due to lack of clinical efficacy. Palivizumab (monoclonal antibody against RSV F-protein) provides monthly passive immunoprophylaxis for high-risk preterm infants (< 29 weeks gestation) or those with congenital heart disease or chronic lung disease.

Cystic Fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene (most commonly Delta-F508 on chromosome 7), resulting in defective cAMP-regulated chloride and bicarbonate conductance across apical epithelial membranes. In the lungs, thick dehydrated secretions impair mucociliary clearance, resulting in chronic colonization with Staphylococcus aureus in infancy and Pseudomonas aeruginosa in adolescents and adults, leading to bronchiectasis and respiratory failure. In the gastrointestinal tract, exocrine pancreatic insufficiency causes fat malabsorption (steatorrhea, deficiency of fat-soluble vitamins A, D, E, K), failure to thrive, and meconium ileus (inspissated meconium obstructing the terminal ileum, demonstrated as microcolon on contrast enema) in up to 20% of newborns.

Definitive diagnosis of CF is made via Quantitative Pilocarpine Iontophoresis (Sweat Chloride Test): sweat chloride concentration ≥ 60 mmol/L on ≥ 2 occasions confirms the diagnosis. Treatment requires a multidisciplinary approach: airway clearance chest physiotherapy, inhaled dornase alfa (DNase) to reduce mucus viscosity, inhaled hypertonic saline, pancreatic enzyme replacement therapy (PERT) administered with all meals, fat-soluble vitamin supplementation, and targeted CFTR modulators (e.g., Elexacaftor-Tezacaftor-Ivacaftor for patients with at least one Delta-F508 allele).

Hypertrophic Pyloric Stenosis results from hypertrophy and hyperplasia of the circular pyloric sphincter muscle, classically presenting in first-born males at 3 to 6 weeks of life with progressive, forceful, projectile non-bilious vomiting immediately after feedings. The infant remains ravenously hungry ('hungry vomiter'). Physical examination reveals an olive-shaped, mobile mass palpated in the right upper quadrant or epigastrium. Transverse abdominal ultrasonography is diagnostic, demonstrating pyloric muscle thickness ≥ 3 mm and channel length ≥ 14 mm. Persistent vomiting of gastric hydrochloric acid produces the classic serum metabolic profile: Hypochloremic, Hypokalemic Metabolic Alkalosis. Surgical pyloromyotomy (Ramstedt procedure) is curative, but must NEVER be performed until intravenous fluid rehydration completely normalizes serum chloride, potassium, and acid-base status.

Intussusception involves telescoping of a proximal bowel segment into an adjacent distal segment (most commonly ileocolic), typically occurring between 6 months and 3 years of age. It presents with sudden, episodic, severe colicky abdominal pain during which the infant draws their knees up to their chest and cries inconsolably, alternating with periods of lethargy. A sausage-shaped abdominal mass is palpated in the right upper quadrant with emptiness in the right lower quadrant (Dance sign). Passage of 'currant jelly stools' (blood and sloughed mucus) is a late sign indicating mucosal ischemia. Abdominal ultrasound is the imaging modality of choice, demonstrating a 'target' or 'doughnut' sign in transverse view. In the absence of peritonitis or bowel perforation, pneumatic (air-contrast) or hydrostatic (barium/saline) enema is both diagnostic and therapeutic (reducing the intussusception in > 85% of cases). In children > 3 years, look for a pathologic lead point (Meckel diverticulum, Henoch-Schönlein purpura hematoma, or Burkitt lymphoma).

Malrotation with Midgut Volvulus occurs due to incomplete 270-degree counterclockwise embryologic rotation of the midgut around the superior mesenteric artery, leaving a narrow mesenteric base anchored by peritoneal Ladd bands crossing the duodenum. Volvulus can present catastrophically at any time (60% in first month of life) with sudden-onset acute bilious (green-yellow) vomiting and abdominal distention in a previously thriving infant. Upper GI fluoroscopy series is the gold standard imaging modality, demonstrating duodenal 'corkscrew' appearance and failure of the duodenojejunal junction (ligament of Treitz) to cross the left midline. Midgut volvulus is a surgical emergency; immediate exploratory laparotomy with Ladd procedure (counterclockwise untwisting, division of Ladd bands, widening of the mesentery, and appendectomy) is life-saving.

Minimal Change Disease (MCD) accounts for > 85% of nephrotic syndrome cases in children aged 2 to 6 years. It is characterized by T-cell mediated cytokine release that causes loss of negatively charged heparan sulfate proteoglycans in the glomerular basement membrane, resulting in selective albuminuria. Children present with periorbital edema that progresses to dependent peripheral edema, ascites, and pleural effusions. Laboratory evaluation confirms the nephrotic tetrad: massive proteinuria (spot urine protein-to-creatinine ratio > 2.0 or 24-hr urine protein > 50 mg/kg/day), profound hypoalbuminemia (< 2.5 g/dL), generalized edema, and secondary hypercholesterolemia. Renal biopsy is NOT indicated in typical presentations; light microscopy is normal, and electron microscopy reveals diffuse effacement of podocyte foot processes. First-line therapy is oral Corticosteroids (Prednisone 2 mg/kg/day × 6 weeks), resulting in complete remission in > 90% of children. Patients are at high risk for encapsulated bacterial peritonitis (Streptococcus pneumoniae) due to urinary loss of immunoglobulins and complement factors, and thromboembolism due to antithrombin III urinary wasting.

Post-Streptococcal Glomerulonephritis (PSGN) is an immune-complex mediated nephritic syndrome occurring 1 to 3 weeks after Group A beta-hemolytic Streptococcal (Streptococcus pyogenes) pharyngitis or 3 to 6 weeks after streptococcal impetigo. Children present with the acute nephritic triad: macroscopic hematuria ('tea-colored' or 'cola-colored' urine with dysmorphic RBCs and RBC casts), periorbital edema, and hypertension with mild oliguria. Laboratory workup reveals low serum complement C3 (which normalizes within 6–8 weeks) and elevated streptococcal antibody titers (anti-streptolysin O [ASO] following pharyngitis; anti-DNase B following impetigo). Light microscopy demonstrates enlarged, hypercellular glomeruli with neutrophil infiltration; immunofluorescence shows granular 'lumpy-bumpy' deposits of IgG and C3; electron microscopy reveals subepithelial 'humps'. Treatment is supportive (fluid and sodium restriction, loop diuretics for fluid overload and hypertension); prognosis in children is excellent (> 95% full recovery).

Hemolytic Uremic Syndrome (HUS) is the leading cause of acute pediatric renal failure, triggered in > 90% of cases by Shiga toxin-producing Escherichia coli (STEC, serotype O157:H7) following ingestion of undercooked ground beef or unpasteurized juice, or Shigella dysenteriae. Following a 3–5 day prodrome of bloody diarrhea and abdominal cramping, the child develops the classic HUS triad: (1) Microangiopathic Hemolytic Anemia (schistocytes, helmet cells on peripheral blood smear, elevated LDH, indirect hyperbilirubinemia, low haptoglobin, negative direct Coombs test); (2) Thrombocytopenia (platelets < 50,000 without petechiae or deep bleeding); and (3) Acute Renal Failure (oliguria, azotemia, hematuria, proteinuria). Treatment is strictly supportive (cautious isotonic fluid hydration, packed RBC transfusions as needed, and hemodialysis in up to 50%). Antibiotics and antimotility agents (loperamide) are STRICTLY CONTRAINDICATED because they increase Shiga toxin release from lysed bacteria, worsening renal thrombotic microangiopathy.

Developmental Dysplasia of the Hip (DDH) involves abnormal development of the femoral head and acetabulum, ranging from subluxation to complete dislocation. Risk factors include breech presentation, female sex, and family history. Screening physical examination maneuvers performed in infancy are: Barlow maneuver (flex and adduct the hip while applying posterior force; attempts to 'dislocate' the unstable hip) and Ortolani maneuver (flex and abduct the hip while applying anterior force on greater trochanter; 'relocates' the dislocated hip with a palpable 'clunk'). After 3 months of age, Galeazzi test (unequal knee heights with hips and knees flexed) and asymmetric thigh skin folds become prominent. Ultrasound of the hip is the imaging modality of choice before 4–6 months (prior to femoral head ossification); pelvic X-rays are used after 6 months. First-line management is a Pavlik harness (splint maintaining hip flexion and abduction) for infants < 6 months.

Transient Synovitis (toxic synovitis) is a benign, self-limiting reactive inflammation of the hip synovial membrane, classically occurring in boys aged 3 to 8 years following a viral upper respiratory infection. The child presents with a limp or refusal to bear weight, mild hip pain, and is afebrile or low-grade. Ultrasound shows a small joint effusion. In sharp contrast, Septic Arthritis of the hip is an orthopedic emergency requiring immediate surgical drainage to prevent femoral head necrosis. Differentiating between the two relies on the Kocher Criteria: (1) Fever > 38.5°C (101.3°F); (2) Inability to bear weight; (3) Erythrocyte sedimentation rate (ESR) > 40 mm/hr; and (4) Serum white blood cell (WBC) count > 12,000/µL (CRP > 2.0 mg/dL added as 5th criterion). The presence of 4 of 4 Kocher criteria carries a > 99% probability of septic arthritis, mandating immediate ultrasound-guided arthrocentesis (synovial fluid WBC > 50,000/µL with > 75% PMNs confirms septic arthritis) and emergent operative arthrotomy.

Legg-Calvé-Perthes Disease is idiopathic avascular necrosis (osteonecrosis) of the femoral head, classically affecting active boys aged 4 to 10 years. It presents with insidious-onset, painless or mildly painful limp exacerbated by activity, with loss of hip internal rotation and abduction. Early pelvis AP and frog-leg lateral radiographs may be normal or show subtle crescent sign; late stages demonstrate femoral head flattening, fragmentation, and sclerosis. Slipped Capital Femoral Epiphysis (SCFE) is the posteromedial displacement of the femoral head through the growth plate (physis), classically occurring in obese adolescent males (aged 10–16 years) during peak pubertal growth spurt. Patients present with dull groin, thigh, or isolated knee pain (referred pain via the obturator nerve) with an antalgic limp. Physical exam reveals obligatory external rotation of the hip during passive hip flexion. Frog-leg lateral pelvis X-ray confirms the slip (Klein's line fails to intersect the lateral aspect of the femoral epiphysis). SCFE is an orthopedic emergency; immediate non-weight-bearing crutches and emergent in situ percutaneous single cannulated screw fixation are required to prevent avascular necrosis and chondrolysis.