Pediatric Emergencies — Part 1: Pediatric Assessment & Resuscitation (PALS)

1. Pediatric Vital Signs by Age

Pediatric vital signs vary dramatically with age, and failure to recognize age-specific normal ranges is a common source of missed deterioration. The following table provides comprehensive normal ranges for heart rate, respiratory rate, systolic blood pressure, and estimated weight from the neonatal period through adolescence. Values represent approximate 5th-95th percentile ranges for resting, afebrile children.^{1 2}

1.1 Complete Vital Signs Reference Table

1.2 Hypotension Definitions by Age

Hypotension in children is a late and ominous finding that indicates decompensated shock. The following thresholds define hypotension in the pediatric population.¹

1.3 Key Vital Sign Principles

• Tachycardia is the earliest and most sensitive sign of distress in children; it may reflect pain, fever, anxiety, hypovolemia, hypoxia, or shock
• Bradycardia in a child is a pre-arrest rhythm until proven otherwise; it typically indicates severe hypoxia or vagal stimulation
• A normal blood pressure does not exclude shock; children compensate through tachycardia and increased systemic vascular resistance, maintaining blood pressure until 25-30% of circulating volume is lost
• Respiratory rate must be counted for a full 30-60 seconds; brief observation commonly underestimates or overestimates rate in young children
• The minimum acceptable systolic blood pressure for a child 1-10 years of age can be estimated as 70 + (2 × age in years) mmHg

2. Pediatric Assessment Triangle

The Pediatric Assessment Triangle (PAT) is a rapid, hands-off observational tool that can be completed within 30 seconds of first patient contact. It provides an immediate general impression of the child’s physiologic status and helps categorize the type and severity of illness before vital signs or monitoring are obtained.^{2 3}

2.1 Three Components of the PAT

2.2 PAT-Based Clinical Categories

3. Weight Estimation

Accurate weight estimation is critical in pediatric emergencies because virtually all medications, fluid volumes, defibrillation energies, and equipment sizes are weight-based. An actual measured weight should be obtained whenever possible, but when a child is too unstable for weighing, validated estimation methods must be used.^{2 4}

3.1 Length-Based Estimation (Broselow Tape)

The Broselow-Luten color-coded length-based tape remains the most widely validated and recommended method for pediatric weight estimation in emergency settings. It estimates weight based on the child’s supine length and categorizes patients into color zones, each linked to precalculated medication doses and equipment sizes.⁴

3.2 Age-Based Weight Estimation Formulas

When a Broselow tape is not available, the following age-based formulas may be used. These formulas are population-derived approximations and may be less accurate in obese or malnourished children.²

3.3 Additional Quick Estimations

• Ideal body weight should be used for medication dosing in obese children (weight-for-length at 50th percentile or BMI at 50th percentile)
• ETT size (cuffed) = (age in years / 4) + 3.5
• ETT size (uncuffed) = (age in years / 4) + 4
• ETT depth of insertion (cm at lip) = ETT internal diameter × 3

4. Pediatric Pulseless Arrest Algorithm

The pediatric pulseless arrest algorithm is the core framework for managing cardiac arrest in children. While ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) are less common initial rhythms in pediatric arrest compared to adults, they carry a higher survival rate when promptly identified and treated. Asystole and pulseless electrical activity (PEA) are the most common initial rhythms, typically resulting from progressive respiratory failure or shock.^{1 5}

4.1 Shockable Rhythms: VF and Pulseless VT

Step-by-step algorithm:

1. Confirm pulselessness — check central pulse (brachial in infant, carotid or femoral in child) for no more than 10 seconds
2. Begin high-quality CPR — compression rate 100-120/min; depth at least one-third AP diameter of chest (~4 cm in infants, ~5 cm in children); allow full chest recoil; minimize interruptions
3. Attach defibrillator/monitor — assess rhythm
4. VF or pVT identified → Defibrillate
   • First shock: 2 J/kg (monophasic or biphasic)
   • Resume CPR immediately for 2 minutes (do not pause to check rhythm)
5. After 2 minutes of CPR → rhythm check
   • If still VF/pVT → Second shock: 4 J/kg
   • Resume CPR immediately
   • Establish IV/IO access during CPR
   • Administer epinephrine 0.01 mg/kg (0.1 mL/kg of 1:10,000 concentration) IV/IO every 3-5 minutes
6. After 2 minutes of CPR → rhythm check
   • If still VF/pVT → Third shock: ≥4 J/kg (maximum 10 J/kg or adult dose)
   • Resume CPR immediately
   • Administer amiodarone 5 mg/kg IV/IO bolus (may repeat twice, maximum 15 mg/kg/day) OR lidocaine 1 mg/kg IV/IO
7. Continue cycle: CPR → rhythm check → shock if shockable → epinephrine every other cycle → consider amiodarone/lidocaine
8. Search for and treat reversible causes (Hs and Ts — see below)

4.2 Non-Shockable Rhythms: Asystole and PEA

Step-by-step algorithm:

1. Confirm pulselessness and begin high-quality CPR
2. Attach defibrillator/monitor — assess rhythm
3. Asystole or PEA identified — rhythm is NOT shockable; do NOT defibrillate
4. Continue CPR for 2 minutes
   • Establish IV/IO access
   • Administer epinephrine 0.01 mg/kg (0.1 mL/kg of 1:10,000) IV/IO as soon as possible, then every 3-5 minutes
5. After 2 minutes of CPR → rhythm check
   • If rhythm becomes shockable → go to VF/pVT algorithm
   • If remains non-shockable → continue CPR, give epinephrine every 3-5 minutes
6. Search for and treat reversible causes aggressively

4.3 Reversible Causes (Hs and Ts)

4.4 CPR Quality Parameters: Infant vs Child

5. Pediatric Bradycardia with Pulse Algorithm

Bradycardia in children is most commonly caused by hypoxia. A heart rate below 60 beats per minute with signs of poor perfusion despite adequate oxygenation and ventilation constitutes a pediatric emergency requiring immediate intervention.^{1 5}

5.1 Algorithm Steps

1. Identify bradycardia — HR <60/min with poor perfusion (altered mental status, weak pulses, pallor, cyanosis, hypotension)
2. Support ABCs — maintain airway, assist ventilation with bag-mask and 100% oxygen, attach monitor
3. Is bradycardia causing cardiorespiratory compromise?
   • If NO — observe, support ABCs, consider cardiology consultation
   • If YES — proceed to step 4
4. Start CPR if HR <60/min with poor perfusion despite oxygenation and ventilation
5. Establish IV/IO access and administer:
   • Epinephrine 0.01 mg/kg (0.1 mL/kg of 1:10,000) IV/IO every 3-5 minutes
   • Atropine 0.02 mg/kg IV/IO (minimum dose 0.1 mg; maximum single dose 0.5 mg) — indicated for increased vagal tone or primary AV block
6. Consider transcutaneous pacing if pharmacotherapy fails
7. Treat underlying cause: hypoxia, hypothermia, head injury, heart block, toxins, increased intracranial pressure

5.2 Key Points

• The most common cause of pediatric bradycardia is hypoxia — effective ventilation is the first intervention
• Atropine is specifically indicated for bradycardia due to vagal stimulation (e.g., suctioning, intubation attempts) or primary AV block
• If the patient has a pulse but the heart rate remains <60 with poor perfusion despite interventions, begin CPR
• Do not delay CPR while waiting for IV/IO access or medications

6. Pediatric Tachycardia with Pulse Algorithm

Tachycardia in children can represent either sinus tachycardia (a physiologic response) or a pathologic tachyarrhythmia. Rapid differentiation between sinus tachycardia and supraventricular tachycardia (SVT) is essential because management differs fundamentally.^{1 5}

6.1 Sinus Tachycardia vs SVT

6.2 Narrow Complex Tachycardia (QRS ≤0.09 sec)

If hemodynamically stable:

1. Attempt vagal maneuvers:
   • Infant: apply ice to face (ice-water mixture in bag/glove over forehead and nose) for 15-20 seconds; do NOT apply ocular pressure
   • Child/adolescent: bear down (Valsalva maneuver), blow through an obstructed straw, carotid sinus massage (older children)
2. If vagal maneuvers fail:
   • Adenosine 0.1 mg/kg IV rapid push (maximum first dose 6 mg) followed by rapid 5-10 mL normal saline flush
   • If ineffective: adenosine 0.2 mg/kg IV rapid push (maximum second dose 12 mg) with rapid flush
   • Adenosine must be given through the most proximal IV site possible, or IO, using rapid push technique with immediate saline flush
3. If adenosine fails: consider synchronized cardioversion or consult pediatric cardiology

If hemodynamically unstable (hypotension, altered consciousness, signs of shock):

1. Synchronized cardioversion: 0.5-1 J/kg
2. If ineffective: increase to 2 J/kg
3. Consider adenosine if IV/IO access is already established and cardioversion setup would cause delay
4. Sedation before cardioversion if the patient’s condition allows (e.g., ketamine 1-2 mg/kg IV or midazolam 0.1 mg/kg IV)

6.3 Wide Complex Tachycardia (QRS >0.09 sec)

Wide complex tachycardia in children should be presumed to be ventricular tachycardia until proven otherwise.¹

If hemodynamically stable:

1. Obtain 12-lead ECG; consult pediatric cardiology
2. Consider adenosine 0.1 mg/kg if rhythm is regular and monomorphic (may be SVT with aberrancy)
3. If confirmed VT: amiodarone 5 mg/kg IV over 20-60 minutes or procainamide 15 mg/kg IV over 30-60 minutes (do not give both simultaneously due to QT prolongation risk)

If hemodynamically unstable:

1. Synchronized cardioversion: 0.5-1 J/kg, escalate to 2 J/kg if needed
2. If polymorphic VT (torsades de pointes): unsynchronized defibrillation and magnesium sulfate 25-50 mg/kg IV (max 2 g) over 10-20 minutes

7. Weight-Based Resuscitation Medication Dosing Table

The following table provides weight-based dosing for all critical resuscitation medications used during pediatric cardiac arrest, peri-arrest arrhythmias, and acute stabilization. All doses should be calculated using actual body weight unless the child is obese, in which case ideal body weight should be used.^{1 5 6}

8. Defibrillation and Cardioversion Energy Levels

8.1 Defibrillation (Pulseless Arrest)

8.2 Synchronized Cardioversion

8.3 Pad/Paddle Sizing

9. Fluid Resuscitation

9.1 Initial Fluid Bolus

• Standard bolus: 20 mL/kg isotonic crystalloid (normal saline or lactated Ringer’s) administered over 5-20 minutes
• Reassess after each bolus: heart rate, blood pressure, capillary refill, mental status, urine output
• Repeat as needed up to 40-60 mL/kg in the first hour for septic shock
• For hemorrhagic shock: 20 mL/kg isotonic crystalloid; if no improvement after 2 boluses, initiate blood product transfusion (10-20 mL/kg pRBCs)
• Exception — DKA: initial bolus 10 mL/kg (not 20 mL/kg); avoid aggressive fluid resuscitation due to cerebral edema risk
• Exception — cardiogenic shock: smaller boluses of 5-10 mL/kg with frequent reassessment; consider early vasopressor/inotrope support^{1 4}

9.2 Blood Product Administration

10. Equipment Sizing by Age and Weight

Appropriate equipment selection is essential to avoid iatrogenic harm during pediatric resuscitation. This table provides recommended sizes for the most critical airway and vascular access equipment by age group.^{2 4}

10.1 Airway Equipment Sizing Table

10.2 Vascular Access Equipment

10.3 IO Access Key Points

• Preferred first-line vascular access in pediatric cardiac arrest when peripheral IV is not immediately available
• Insertion site: proximal tibia (1 cm below and 1 cm medial to tibial tuberosity) is the primary site; distal tibia, distal femur, and humeral head are alternatives
• Any medication or fluid that can be given IV can be given IO, including blood products and vasoactive infusions
• IO access should be replaced with definitive IV access within 24 hours to reduce infection risk¹

11. Post-Resuscitation Care

Following return of spontaneous circulation (ROSC) in a pediatric patient, the focus shifts to stabilization and prevention of secondary injury.^{1 5}

11.1 Immediate Post-ROSC Management