• a. Canakinumab: Interleukin-1$\beta$ (IL-1$\beta$) receptor antagonist / monoclonal antibody
• b. Mycophenolate mofetil: Inosine monophosphate dehydrogenase (IMPDH) inhibitor (inhibits de novo purine synthesis in lymphocytes)
• c. Tocilizumab: Interleukin-6 (IL-6) receptor antagonist / monoclonal antibody
• d. Abatacept: CTLA-4-Ig fusion protein that binds to CD80 and CD86, blocking CD28 co-stimulation of T cells
• e. Daclizumab: Interleukin-2 (IL-2) receptor ($\alpha$-chain / CD25) antagonist
• f. Belimumab: B-lymphocyte stimulator (BLyS / BAFF) antagonist

• a. Lamotrigine: Stevens–Johnson syndrome (SJS) / Toxic Epidermal Necrolysis (TEN), rash
• b. Sodium Valproate: Acute pancreatitis, fulminant hepatotoxicity, weight gain, alopecia, hyperammonemia, and teratogenicity (neural tube defects)
• c. Carbamazepine: Agranulocytosis / aplastic anemia, hyponatremia (SIADH), hepatotoxicity
• d. Phenytoin: Pseudolymphoma, gingival hyperplasia, hirsutism, cerebellar ataxia, megaloblastic anemia
• e. Topiramate: Secondary angle-closure glaucoma, hypohidrosis / hyperthermia, nephrolithiasis, metabolic acidosis, weight loss
• f. Vigabatrin: Irreversible concentric visual field defects / retinal toxicity

• a. Levetiracetam: Binds selectively to the presynaptic vesicle glycoprotein SV2A, modulating synaptic vesicle exocytosis and neurotransmitter release.
• b. Indications: Focal-onset seizures, generalized tonic-clonic seizures (GTCS), myoclonic seizures (e.g., Juvenile Myoclonic Epilepsy), and status epilepticus second-line therapy.
• c. Dose:
  • Loading for status epilepticus: $40\text{–}60\text{ mg/kg}$ IV over 10–15 minutes.
  • Maintenance: $20\text{–}60\text{ mg/kg/day}$ orally or IV divided in 2 doses.
• d. Adverse effects: Behavioral disturbances (irritability, aggression, mood swings, hyperactivity), somnolence, fatigue, headache, dizziness.

• a. Indications: Acute severe asthma (refractory bronchospasm), symptomatic hypomagnesemia, refractory hypocalcemia, Torsades de pointes, pulmonary hypertension of the newborn (PPHN), and eclampsia.
• b. Dose & Content:
  • Dose in asthma: $25\text{–}50\text{ mg/kg/dose}$ IV infusion over 20–30 minutes (maximum $2\text{ g}$).
  • Elemental content: 50% ${\text{MgSO}}_4$ contains $500\text{ mg/mL}$ ($50\text{ g}/100\text{ mL}\approx 4{\text{ mEq Mg}}^{2+}/\text{mL}$).
• c. Monitoring: Continuous heart rate and ECG (bradycardia, heart block), blood pressure (hypotension), respiratory rate (respiratory depression), and deep tendon reflexes (loss of patellar reflex indicates toxicity).
• d. Mechanism: Competes with calcium channels on bronchial smooth muscle causing bronchodilation, inhibits acetylcholine release at motor nerve terminals, and stabilizes mast cell membranes reducing histamine release.

• a. Competitively blocks macrophage Fc receptors in the reticuloendothelial system (preventing phagocytosis of antibody-coated cells), neutralizes circulating autoantibodies and superantigens, suppresses pathogenic cytokine expression, and modulates regulatory T-cell function.
• b. Indications: Kawasaki disease, Immune Thrombocytopenia (ITP), Guillain–Barré syndrome (GBS), Primary Immunodeficiencies (e.g., X-linked agammaglobulinemia, SCID), Systemic-onset JIA (sJIA), and Toxic Shock Syndrome.
• c. Adverse effects: Anaphylaxis (especially in IgA-deficient patients), aseptic meningitis, headache, fever/chills, acute kidney injury (osmotic nephrosis from sucrose stabilizers), transfusion-related acute lung injury (TRALI), and thrombosis.
• d. Preparation: Sterile purified polyvalent immunoglobulin G (IgG $>95\mathrm{\%}$) fractionated and pooled from plasma of $>1,000\text{–}10,000$ healthy human donors, treated with viral inactivation steps.

• a. Antimicrobial spectrum: Broad-spectrum coverage against Gram-negative bacilli including Pseudomonas aeruginosa, Klebsiella, E. coli, Enterobacter; Gram-positive bacteria including methicillin-susceptible Staphylococcus aureus (MSSA), Streptococcus pneumoniae, Enterococcus faecalis; and anaerobes including Bacteroides fragilis.
• b. Dose: $300\text{–}400\text{ mg/kg/day}$ (based on piperacillin component) IV divided every 6 to 8 hours (maximum single dose $4.5\text{ g}$).
• c. Adverse effects: Hypersensitivity/anaphylaxis, neutropenia/leukopenia (with prolonged therapy), thrombocytopenia, antibiotic-associated diarrhea / Clostridioides difficile colitis, hypokalemia, and elevated hepatic transaminases.
• d. Class: Antipseudomonal extended-spectrum penicillin (ureidopenicillin) combined with a $\beta$-lactamase inhibitor.

• a. Indications: Vasodilatory / septic shock with low systemic vascular resistance (warm shock) refractory to fluid resuscitation, and neurogenic shock; neuro-intensive care to maintain Mean Arterial Pressure (MAP) and ensure adequate Cerebral Perfusion Pressure (CPP).
• b. Target receptors: Potent agonist at ${\alpha }_1$ and ${\alpha }_2$ adrenergic receptors (producing intense vasoconstriction), with modest agonist activity at ${\beta }_1$ adrenergic receptors (mild positive inotropy).
• c. Infusion dose: $0.05\text{–}1.0\mu \text{g/kg/min}$ (titrated to target MAP).
• d. Adverse effects: Peripheral limb ischemia, extravasation tissue necrosis, reflex bradycardia, excessive hypertension, myocardial ischemia/arrhythmias, and increased cardiac afterload.

Image	Device Name	Flow Rate	Delivered ${\text{FiO}}_2$	Advantages	Disadvantages
A	Nasal Cannula	$0.25\text{–}4\text{ L/min}$	$22\text{–}40\mathrm{\%}$ (variable)	Well tolerated in infants/children; allows feeding and vocalization; low cost.	Variable ${\text{FiO}}_2$ dependent on inspiratory flow; nasal mucosal drying.
B	Simple Face Mask	$6\text{–}10\text{ L/min}$	$35\text{–}60\mathrm{\%}$	Easy to apply; higher ${\text{FiO}}_2$ than low-flow cannula.	Must maintain $\ge 5\text{ L/min}$ to prevent ${\text{CO}}_2$ rebreathing; poorly tolerated in agitated infants.
C	Non-Rebreathing Mask (NRBM)	$10\text{–}15\text{ L/min}$	$90\text{–}95\mathrm{\%}$	Delivers very high ${\text{FiO}}_2$ for emergency resuscitation; reservoir with one-way valve prevents rebreathing.	Requires tight seal; non-humidified; not suitable for prolonged long-term use.

• a. Metered-Dose Inhaler (MDI): Compact pressurized canister containing micronized drug in propellant (e.g., Hydrofluoroalkane, HFA) and surfactant, seated in an actuator casing with metering valve and mouthpiece.
• b. Add a valved holding chamber / spacer with a silicone face mask. Young children cannot synchronize actuation with inspiration (lack hand-lung coordination); spacers eliminate coordination requirements, slow aerosol velocity, and decrease oropharyngeal deposition.
• c.
  • Inhaled short-acting and long-acting ${\beta }_2$-agonists (Salbutamol, Formoterol, Salmeterol).
  • Inhaled corticosteroids (Budesonide, Fluticasone, Beclomethasone).
  • Anticholinergics (Ipratropium bromide).
• d.
  • Advantages: Compact, portable, multi-dose, no electricity required, rapid pulmonary delivery.
  • Disadvantages: Requires precise actuation-inhalation coordination without spacer; high oropharyngeal impaction (risk of oral thrush / dysphonia); difficult in severe respiratory distress.

• a. Lumbar Puncture (LP) Needle — Quincke type (with matched stylet and cutting bevel).
• b.
  • Diagnostic indications: Evaluation of suspected meningitis/encephalitis, measurement of opening CSF pressure in idiopathic intracranial hypertension, and staging/evaluation of leukemic CNS infiltration.
  • Therapeutic indications: Intrathecal chemotherapy (e.g., Methotrexate, Cytarabine), spinal anesthesia, and CSF drainage in benign intracranial hypertension.
• c. Side effects: Post-dural puncture headache (PDPH), local back pain, epidural hematoma / bleeding, introduction of infection (meningitis/discitis), and intraspinal epidermoid tumor (if performed without stylet).
• d. Contraindications: Signs of raised intracranial pressure with mass lesion/focal deficit (risk of uncal/tonsillar herniation), severe thrombocytopenia ($\text{platelets}<50,000/\mu \text{L}$) or uncorrected coagulopathy, and local skin infection at the puncture site (L3–L5).

• a.
  • A: Pressure-limiting pop-off valve / relief valve
  • B: Non-rebreathing patient valve (duckbill/fish-mouth valve)
  • C: Self-inflating silicone ventilation bag
  • D: Oxygen reservoir bag with inlet tubing adapter
• b. Bag volumes:
  • i. Neonates: $240\text{–}250\text{ mL}$
  • ii. Infants and young children (1–8 years): $500\text{ mL}$
  • iii. Older children and adolescents: $1,000\text{–}1,500\text{ mL}$
• c. Pop-off valve (A): Opens at $35\text{–}40{\text{ cm H}}_2\text{O}$ to release excess pressure and protect pediatric lungs from pulmonary barotrauma.
• d. Mask sizing: Must extend from the bridge of the nose to the cleft of the chin without covering the eyes or extending beyond the chin border, achieving an airtight seal.
• e. Reservoir bag: Increases delivered ${\text{FiO}}_2$ from $40\text{–}50\mathrm{\%}$ (room air entrainment) up to $90\text{–}100\mathrm{\%}$ when oxygen flow is $\ge 10\text{–}15\text{ L/min}$.
• f. Complications: Pulmonary barotrauma/pneumothorax, gastric insufflation leading to vomiting and aspiration, and hypoventilation/hyperventilation.

• a. Cuffed Endotracheal Tube (ETT):
  • Size (Internal Diameter, ID in mm) selection formula:
    $\text{Uncuffed ETT size}=\frac{\text{Age in years}}{4}+4$
    $\text{Cuffed ETT size}=\frac{\text{Age in years}}{4}+3.5$
• b.
  • A (Vocal cord guide): Black line indicator positioned at the level of the vocal cords during laryngoscopy to ensure appropriate depth.
  • G (Beveled tip): Angled opening allowing smooth passage through glottis with optimal visualization.
  • H (Murphy’s eye): Side hole at distal tip providing an alternate airway channel if the primary bevel becomes occluded by secretions or the tracheal wall.
• c. C (Inflatable cuff): Provides an airtight low-pressure seal against the tracheal mucosa to prevent air leak and reduce microaspiration.
• d.
  • D (Inflation line with spring-loaded one-way valve): Channel for injecting air to inflate the cuff.
  • F (Pilot balloon): External indicator providing tactile and visual assessment of cuff inflation pressure ($20\text{–}25{\text{ cm H}}_2\text{O}$).
• e. Depth of insertion:
  $\text{Depth at lip (cm)}=\frac{\text{Age in years}}{2}+12\text{ (or Internal Diameter}\times 3\text{)}$
• f. Confirmation methods: Continuous waveform capnography (${\text{ETCO}}_2>30\text{ mm Hg}$ for $\ge 6$ breaths — Gold Standard), 5-point chest/epigastric auscultation, symmetric bilateral chest rise, tube misting, and confirmation on chest radiograph (tip at T2–T3).

• a. Hereditary Spherocytosis (HS) (suggested by neonatal hemolytic anemia, jaundice, splenomegaly, and high MCHC $>36\text{ g/dL}$).
• b. Eosin-5-maleimide (EMA) binding test by flow cytometry (detects decreased fluorescence binding to Band 3 and Rh-related proteins).
• c. Mutations in erythrocyte membrane skeletal proteins: Ankyrin-1 (ANK1), Spectrin ($\alpha$ and $\beta$), Band 3 (SLC4A1), or Protein 4.2.
• d. Transient Aplastic Crisis caused by Parvovirus B19 infection.
• e. Autosomal dominant in $\approx 75\mathrm{\%}$ of cases (autosomal recessive in 25%).

• a. Factor XIII (Fibrin stabilizing factor) deficiency complicated by intracranial hemorrhage (normal PT, aPTT, and platelet count).
• b. Quantitative Factor XIII activity assay (or clot solubility test in 5M urea / 1% monochloroacetic acid).
• c. Emergency stabilization: Intracranial decompression, neuroprotective care, and immediate factor replacement with Factor XIII concentrate ($20\text{–}40\text{ IU/kg}$ IV) or Cryoprecipitate / Fresh Frozen Plasma (FFP).
• d. Delayed umbilical cord bleeding in neonates, poor wound healing with abnormal scar formation, and recurrent spontaneous miscarriages in females.
• e.
  • Treatment for acute bleeding / surgery: FXIII concentrate $20\text{–}40\text{ IU/kg}$.
  • Routine secondary prophylaxis: FXIII concentrate $20\text{–}40\text{ IU/kg}$ IV every 4 weeks (due to long half-life of 10–14 days) to maintain trough activity $>5\text{–}10\mathrm{\%}$.

• a. Subependymal nodules (SENs) and cortical tubers associated with Tuberous Sclerosis Complex (TSC).
• b.
  • TSC1 gene: Located on chromosome 9q34 (encodes Hamartin).
  • TSC2 gene: Located on chromosome 16p13 (encodes Tuberin).
• c. Facial angiofibromas (adenoma sebaceum), hypomelanotic macules (ash-leaf spots), shagreen patch, cardiac rhabdomyoma, subependymal giant cell astrocytoma (SEGA), and renal angiomyolipoma.
• d. Neurofibromatosis type 1 (NF1), Sturge-Weber syndrome, Von Hippel-Lindau disease, and PHACE syndrome.
• e. Vigabatrin (GABA-transaminase inhibitor).

• a. Primary Sjögren syndrome (or Juvenile Recurrent Parotitis).
• b. Minor salivary gland / labial lip biopsy showing focal lymphocytic sialadenitis (focus score $\ge 1$ focus of 50 lymphocytes per $4{\text{ mm}}^2$).
• c. Anti-SSA (Ro) and Anti-SSB (La) antibodies (along with ANA and Rheumatoid Factor).
• d. Schirmer's test ($<5\text{ mm}$ wetting in 5 minutes), Rose Bengal / fluorescein corneal staining, and salivary gland ultrasonography / sialometry.
• e. Juvenile recurrent parotitis (JRP), viral parotitis (mumps, CMV, EBV, HIV), bacterial suppurative sialadenitis, and IgG4-related disease.

• a. Wilson’s disease (Hepatolenticular degeneration).
• b. Autosomal recessive; mutation in the ATP7B gene on chromosome 13q14.3.
• c.
  • Low serum ceruloplasmin ($<20\text{ mg/dL}$, normal 20–40 mg/dL).
  • 24-hour urinary copper excretion ($>40\text{–}100\mu \text{g/day}$ or $>1.6\mu \text{mol/day}$).
• d. Hepatic copper concentration $>250\mu \text{g/g}$ dry weight on liver biopsy; presence of Kayser–Fleischer (KF) rings on slit-lamp examination.
• e. Chelation therapy: D-Penicillamine ($20\text{ mg/kg/day}$) or Trientine ($20\text{ mg/kg/day}$), followed by maintenance Zinc acetate/gluconate (which induces intestinal metallothionein).

• a. Hyperglycemia ($457\text{ mg/dL}$), hyperketonemia ($4.6\text{ mmol/L}$), severe metabolic acidemia (pH 7.005), and severe bicarbonate depletion ($2\text{ mEq/L}$) — Diabetic Ketoacidosis (DKA).
• b. Fluid management:
  • Initial resuscitation: $0.9\mathrm{\%}$ Normal Saline $10\text{ mL/kg}=350\text{ mL}$ over 1 hour.
  • Deficit + Maintenance over 48 hours:
    $\text{Deficit (8.5\%)}=85\text{ mL/kg}\times 35\text{ kg}=2,975\text{ mL}$
    $\text{Maintenance (48 hr)}=1,800\text{ mL/day}\times 2=3,600\text{ mL}$
    $\text{Total 48-hr fluid}=(2,975+3,600)-350=6,225\text{ mL}⟹129\text{ mL/hour}$
• c. **Expected }\text{pCO}_2\text{ (Winter's formula):}
  $\text{Expected }{\text{pCO}}_2=(1.5\times {\text{HCO}}_3)+8\pm 2=(1.5\times 2)+8\pm 2=11\pm 2=9\text{–}13\text{ mm Hg}$
  Actual ${\text{pCO}}_2$ is $8.3\text{ mm Hg}$, indicating appropriate full respiratory compensation.
• d. Severe High Anion Gap Metabolic Acidosis (HAGMA).
• e.
  • $\text{Anion Gap}=\text{Na}-(\text{Cl}+{\text{HCO}}_3)=132-(103+2)=27\text{ mEq/L}$ (HAGMA)
  • $\mathrm{\Delta }\text{AG}=27-12=15$
  • $\mathrm{\Delta }{\text{HCO}}_3=24-2=22$
  • $\text{Delta ratio}=\frac{\mathrm{\Delta }\text{AG}}{\mathrm{\Delta }{\text{HCO}}_3}=\frac{15}{22}=0.68$ (Mixed HAGMA + NAGMA)
• f. Corrected Sodium:
  $\text{Corrected }{\text{Na}}^{+}=\text{Measured }{\text{Na}}^{+}+2\times \left(\frac{\text{Glucose}-100}{100}\right)=132+2\times \left(\frac{457-100}{100}\right)=132+7.14=139.1\text{ mEq/L}$
• g. Effective Serum Osmolality:
  $\text{Osmolality}=2\times {\text{Na}}^{+}+\frac{\text{Glucose (mg/dL)}}{18}+\frac{\text{BUN (mg/dL)}}{2.8}$

• a. Microcytic hypochromic anemia with high red cell distribution width (RDW $>15\mathrm{\%}$).
• b. Mentzer Index:
  $\text{Mentzer Index}=\frac{\text{MCV}}{\text{RBC count}}=\frac{69.7}{4.28}=16.3$
  • $>13$: Suggestive of Iron Deficiency Anemia
  • $<13$: Suggestive of $\beta$-Thalassemia trait
• c. Reticulocyte Production Index (RPI):

$\text{RPI}=\text{Reticulocyte }\mathrm{\%}\times \frac{\text{Patient HCT}}{\text{Normal HCT (35)}}\times \frac{1}{\text{Maturation factor (2)}}=4.0\times \frac{29}{35}\times \frac{1}{2}=1.65$

• d. Absolute Neutrophil Count (ANC):
  $\text{ANC}=\frac{(\mathrm{\%}\text{Polymorphs}+\mathrm{\%}\text{Bands})\times \text{Total WBC}}{100}=\frac{(22+3)\times 4000}{100}=1,000/\mu \text{L}$
  Interpretation: Moderate neutropenia (normal ANC $>1,500/\mu \text{L}$).
• e. Corrected ESR:
  $\text{Corrected ESR}=\text{Observed ESR}-[(35-\text{Observed HCT})\times 1.75]=35-[(35-29)\times 1.75]=35-10.5=24.5\text{ mm/hr}$

• a. Alveolar-arterial Oxygen Gradient (${\text{AaDO}}_2$):
  ${\text{PAO}}_2=[{\text{FiO}}_2\times (760-47)]-\frac{{\text{PaCO}}_2}{R}=[0.21\times 713]-\frac{50}{0.8}=149.7-62.5=87.2\text{ mm Hg}$
  ${\text{AaDO}}_2={\text{PAO}}_2-{\text{PaO}}_2=87.2-68=19.2\text{ mm Hg}$
  Interpretation: Elevated ${\text{AaDO}}_2$ gradient indicating ventilation-perfusion ($V/Q$) mismatch secondary to acute bronchospasm/airway obstruction.
• b. Severe acute asthma exacerbation, foreign body aspiration, and severe pneumonia.
• c. Oxygenation Index (OI):
  $\text{OI}=\frac{{\text{FiO}}_2\times \text{Mean Airway Pressure (MAP)}\times 100}{{\text{PaO}}_2}$
• d. $\text{OI}>25$ (or ${\text{PaO}}_2/{\text{FiO}}_2<100$).
• e. Pure alveolar hypoventilation due to central respiratory depression (e.g., opioid intoxication, brainstem injury) or high altitude.

• a. Acute Respiratory Distress Syndrome (ARDS) / Pediatric ARDS (PARDS).
• b. ${\text{PaO}}_2/{\text{FiO}}_2$ (P/F) ratio:
  • Severe PARDS: $\text{P/F}\le 100$ or $\text{OI}\ge 16$
  • Moderate PARDS: $\text{P/F }101\text{–}200$ or $\text{OI }8\text{–}16$
  • Mild PARDS: $\text{P/F }201\text{–}300$ or $\text{OI }4\text{–}8$
• c. Lung protective ventilation: Low tidal volume ($4\text{–}6\text{ mL/kg}$ predicted body weight), permissive hypercapnia ($\text{pH}\ge 7.20$), plateau pressure $<28\text{–}30{\text{ cm H}}_2\text{O}$, and titrated optimal PEEP ($10\text{–}15{\text{ cm H}}_2\text{O}$).
• d. $\text{OI}>40$ (or refractory hypoxemia / severe hypercapnic respiratory failure despite lung-protective ventilation and neuromuscular blockade/prone positioning).

• a. Fractional Excretion of Sodium ($\text{FeNa}$):
  $\text{FeNa}=\frac{\text{Urine Na}\times \text{Serum Creatinine}}{\text{Serum Na}\times \text{Urine Creatinine}}\times 100=\frac{143\times 0.8}{148\times 0.7}\times 100\approx 0.9\mathrm{\%}$
  Interpretation: $\text{FeNa}<1\mathrm{\%}$ signifies Prerenal Acute Kidney Injury (hypovolemia/dehydration).
• b. Estimated GFR (Updated Bedside Schwartz formula):
  $\text{eGFR}=\frac{0.413\times \text{Height (cm)}}{\text{Serum Creatinine (mg/dL)}}=\frac{0.413\times 66}{0.8}=34.1{\text{ mL/min/1.73 m}}^2$
  (Or using classical $k=0.55$: $\text{eGFR}=\frac{0.55\times 66}{0.8}=45.3{\text{ mL/min/1.73 m}}^2$).
• c. Increased ($>500\text{ mOsm/kg}$ due to maximal tubular water reabsorption).
• d. KDIGO Stage 2 AKI (Urine output $<0.5\text{ mL/kg/hr}$ for $\ge 12$ hours / $2.0\text{–}2.9\times$ baseline creatinine).

• a. Exogenous natural surfactant replacement therapy (e.g., Poractant alfa $200\text{ mg/kg}$ or Beractant $100\text{ mg/kg}$).
• b.
  • INSURE technique: INtubate – SUrfactant – RExtubate to CPAP.
  • Newer non-invasive modalities: LISA (Less Invasive Surfactant Administration) / MIST (Minimally Invasive Surfactant Therapy) using a thin vascular catheter or feeding tube while baby remains on spontaneous breathing CPAP; and aerosolized/nebulized surfactant.
• c. Neonatal RDS in preterm infants failing CPAP (${\text{FiO}}_2>0.30\text{–}0.40$), meconium aspiration syndrome (MAS), severe neonatal pneumonia, and pulmonary hemorrhage.
• d. Acute airway obstruction / desaturation, bradycardia, pulmonary hemorrhage, uneven distribution / localized air leak (pneumothorax), and rapid changes in cerebral blood flow.

• a. Intraosseous (IO) vascular access.
• b. Sites:
  • Anteromedial surface of proximal tibia ($1\text{–}2\text{ cm}$ below and medial to tibial tuberosity — preferred).
  • Distal femur ($2\text{–}3\text{ cm}$ above external condyle).
  • Distal tibia ($1\text{–}2\text{ cm}$ proximal to medial malleolus).
  • Proximal humerus (greater tubercle).
• c. Emergency vascular access in cardiopulmonary arrest, decompensated shock, or status epilepticus when IV access cannot be established within 90 seconds / 3 attempts.
• d. Contraindications: Ipsilateral bone fracture, severe osteogenesis imperfecta / osteopetrosis, overlying cellulitis/burns, and previous failed IO attempt in the same bone.
• e. Confirm position (aspiration of bone marrow), administer pressurized rapid flushes (bone marrow offers high vascular resistance), use sterile technique, and remove within 24 hours once definitive venous access is secured.

• a. Umbilical Venous Catheter (UVC).
• b. Indications: Emergency vascular access during neonatal delivery room resuscitation, central venous pressure monitoring, exchange transfusion, administration of hyperosmolar solutions / TPN, inotropes, and blood products.
• c. Recommended maximum duration is 7 to 10 days (ideally $<14$ days).
• d. Complications:
  • Catheter-related bloodstream infections (sepsis), hepatic abscess.
  • Catheter-related thrombosis (portal vein thrombosis, IVC thrombosis).
  • Malposition complications: Cardiac arrhythmias, pericardial effusion / cardiac tamponade, pleural effusion.
  • Extravasation into liver parenchyma causing hepatic necrosis.

• a. Traumatic hemothorax / pneumothorax with hemorrhagic shock and respiratory failure.
• b. Intercostal Drainage (ICD) / Tube Thoracostomy (inserted in the 4th/5th intercostal space, anterior to mid-axillary line in the "safe triangle").
• c. Pneumothorax (tension or large), hemothorax, large pleural effusion, empyema, and post-thoracotomy drainage.
• d. Diaphragmatic hernia, extensive pleural adhesions / fibrothorax, and uncorrected severe coagulopathy.
• e. Criteria for removal:
  • Full lung re-expansion confirmed on chest radiograph.
  • Absence of air leak for $\ge 24$ hours on underwater seal.
  • Minimal non-purulent drainage ($<1\text{–}2\text{ mL/kg/day}$).

• a. Bone Marrow Aspiration and Biopsy.
  • Indications: Evaluation of suspected acute leukemia / myelodysplasia, unexplained pancytopenia/bicytopenia, staging of lymphomas/solid tumors (neuroblastoma), and evaluation of storage disorders / pyrexia of unknown origin.
• b. Anatomical sites:
  • Posterior superior iliac spine (PSIS) (preferred site in all pediatric age groups).
  • Anterior iliac crest.
  • Anteromedial surface of proximal tibia (infants $<1$ year).
  • Sternum (only in older adolescents $>12$ years).
• c. Bleeding / local hematoma, site infection, procedural pain, sedation-related complications, and rare bone fracture or retroperitoneal hemorrhage.
• d. Dry tap: Inability to aspirate bone marrow fluid despite proper needle placement.
  • Causes: Myelofibrosis, packed bone marrow due to acute leukemia, aplastic anemia, metastatic neuroblastoma / solid tumor infiltration, and hairy cell leukemia.