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Rectal temp >= 38.0°C requires full septic workup (LP, blood/urine cultures) + IV Amp/Gent
Causes biliary sludging and displaces bilirubin from albumin (kernicterus risk)
20 mL/kg isotonic balanced crystalloid (Lactated Ringer's) over 10–20 min
Initial shock 2 J/kg; subsequent shocks 4 J/kg (max 10 J/kg or adult 200J)
0.01 mg/kg IV/IO (0.1 mL/kg of 1:10,000 solution) q3–5min
Bottom-Line Clinical Pearl
In infants <= 28 days of age, fever (rectal temp >= 38.0°C/100.4°F) is an absolute medical emergency mandating a full sepsis workup: blood cultures x2, catheterized urinalysis/culture, lumbar puncture, and IV Ampicillin + Gentamicin or Cefotaxime (AVOID Ceftriaxone in neonates). Children maintain normal blood pressure in shock until 30–40% of intravascular volume is lost—hypotension is a pre-terminal sign. Administer 20 mL/kg balanced crystalloids rapidly.
In pediatric emergency medicine, fever is strictly defined as a rectal core temperature >= 38.0°C (100.4°F). Evaluation and management are rigidly categorized by age brackets reflecting immune maturity and bacterial pathogen profiles:
| Age Group | Bacterial Pathogens | Mandatory Diagnostic Workup | Empiric Antimicrobial Regimen & Disposition |
|---|---|---|---|
| Neonate (0 to 28 Days) | Group B Streptococcus (GBS), Escherichia coli, Listeria monocytogenes, Herpes Simplex Virus (HSV) | FULL SEPSIS WORKUP: Blood cultures x2, catheterized urinalysis & culture, Lumbar Puncture (CSF cell count, protein, glucose, Gram stain, viral PCR), CXR if respiratory signs | Ampicillin (50 mg/kg IV q8h) + Gentamicin (2.5 mg/kg IV q12h) OR Cefotaxime (50 mg/kg IV q8h). Add Acyclovir (20 mg/kg IV q8h) if vesicles, seizures, or maternal HSV. MANDATORY ADMISSION. |
| Young Infant (29 to 60 Days) | Streptococcus pneumoniae, Neisseria meningitidis, E. coli, GBS | Apply AAP 2021 Guidelines: Catheterized UA, blood culture, procalcitonin, CRP, ANC. Lumbar puncture indicated if high-risk inflammatory markers or unimmunized | If low-risk (normal inflammatory markers, normal UA, feeding well): Ceftriaxone 50 mg/kg IV or close outpatient observation with 24h follow-up. If high-risk: LP + Ceftriaxone 50 mg/kg + Vancomycin + Admit. |
| Older Infant (61 to 90 Days) | E. coli (UTI is #1 source), S. pneumoniae | Catheterized urinalysis & culture. Procalcitonin/CRP if appearing unwell or under-immunized | If urinalysis positive: Ceftriaxone 50 mg/kg IV/IM or oral cephalosporin. Outpatient management if clinically reassuring. |
Critical Pitfall / Contraindication
Ceftriaxone Contraindication in Neonates (< 28 Days): Ceftriaxone is strictly contraindicated in neonates under 28 days of age. It displaces bilirubin from albumin binding sites, crossing the immature blood-brain barrier to cause kernicterus (bilirubin encephalopathy). It also precipitates with intravenous calcium-containing solutions (e.g., parenteral nutrition), forming lethal microcrystalline deposits in the lungs and kidneys. Use Cefotaxime or Gentamicin instead.
Children possess robust cardiovascular compensatory mechanisms: they increase systemic vascular resistance and heart rate aggressively to maintain normal blood pressure during hypovolemia. Hypotension is a late, catastrophic sign of imminent arrest indicating that > 30–40% of circulating volume is gone.
| Phase of Shock | Systolic Blood Pressure Threshold | Clinical Signs & Examination | Emergency Action |
|---|---|---|---|
| Compensated Shock | NORMAL for age [Minimum normal SBP: 70 + (2 x Age in years)] | Persistent tachycardia, delayed capillary refill (> 2–3 sec), cool mottled extremities, weak peripheral pulses with bounding central pulses, oliguria | Immediate 20 mL/kg balanced crystalloid bolus over 10–20 minutes; repeat up to 40–60 mL/kg with frequent reassessment. |
| Decompensated Shock | HYPOTENSIVE: Neonate < 60 mmHg; Infant < 70 mmHg; Child 1–10 yr < 70 + (2 x Age); Child > 10 yr < 90 mmHg | Profound lethargy, central cyanosis, absent peripheral pulses, weak thready central pulses, agonal breathing | Push-pull 20 mL/kg fluid bolus immediately; establish intraosseous (IO) access; initiate early inotropic/vasopressor support (Epinephrine). |
| Cold Shock (Poor perfusion) | Normal or low BP; prolonged cap refill; cold extremities | Elevated systemic vascular resistance, low cardiac output | Epinephrine infusion (0.05–0.3 mcg/kg/min) is the first-line inotrope. |
| Warm Shock (Vasodilatory) | Low BP; flash capillary refill (< 1 sec); bounding pulses | Low systemic vascular resistance, warm flushed skin | Norepinephrine infusion (0.05–0.3 mcg/kg/min) is the first-line vasopressor. |
| PALS Element | First-Line Regimen | Administration Route & Technique | Critical Formulas & Safety Limits |
|---|---|---|---|
| Endotracheal Tube Size | Cuffed Tube preferred | Cuffed formula: (Age/4) + 3.5; Uncuffed formula: (Age/4) + 4.0 | Keep cuff pressure < 20 cmH2O to prevent subglottic tracheal mucosal ischemia. |
| Defibrillation (VF/pVT) | Initial shock: 2 J/kg | Biphasic defibrillator pads (anterior-posterior position in infants/small children) | Second and subsequent shocks: 4 J/kg; maximum 10 J/kg or adult dose (200 J). |
| Synchronized Cardioversion | 0.5–1.0 J/kg for SVT/VT with pulse | Engage SYNC button; verify synchronization flag on R-wave | Increase to 2 J/kg if refractory to initial cardioversion. |
| Epinephrine in Cardiac Arrest | 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution) | IV or Intraosseous (IO) q3–5min | Maximum single dose: 1.0 mg (10 mL of 1:10,000). Flush with 5 mL normal saline. |
| Amiodarone in Refractory VF | 5 mg/kg IV/IO rapid bolus | May repeat 5 mg/kg bolus up to total 15 mg/kg (max 300 mg) | Alternatively: Lidocaine 1.0 mg/kg IV/IO loading dose. |
| Pediatric Hypoglycemia Rescue | Rule of 50: D10W (5 mL/kg) or D25W (2 mL/kg) or D50W (1 mL/kg) | Infants/Neonates: Use D10W ONLY (5 mL/kg = 0.5 g/kg) IV slow push | D50W is hyperosmolar and causes intracranial hemorrhage in infants; never use D50W in patients < 2 years. |
Test Your Pediatric Emergencies: Fever & Resuscitation Clinical Acumen
Directly launch an active-recall practice block from our validated question bank with comprehensive explanations and distractor analyses.
Distinguish primary life-threats from mimics. On board exams (COMLEX Level 1, 2-CE, 3 & USMLE), initial stabilizing interventions (airway, IV access, non-invasive ventilation, empiric reversal) always take precedence over diagnostic imaging.
Evaluate autonomic tone: Sympathetic viscerosomatics (T1–L2) cause acute paraspinal tissue texture changes (erythema, bogginess, hypertonicity). Suboccipital release (CN X Vagus) and rib raising normalize autonomic outflow and thoracic cage mechanics.