Understanding PALS: Pediatric Advanced Life Support Protocols in Clinical Practice

Pediatric Advanced Life Support (PALS) is a systematic clinical framework developed by the American Heart Association (AHA) and the International Liaison Committee on Resuscitation (ILCOR). It provides structured guidance for healthcare professionals managing critically ill or injured infants and children, specifically focusing on cardiorespiratory arrest, shock, and acute respiratory failure.

The primary clinical goal of PALS differs significantly from Adult Advanced Cardiac Life Support (ACLS). In adults, sudden cardiac arrest is frequently primary and cardiac in origin (such as ischemic heart disease or arrhythmia). In contrast, pediatric cardiac arrest is typically secondary, arising as the terminal pathway of progressive respiratory failure or decompensated shock. Therefore, early recognition and aggressive management of pre-arrest states represent the cornerstone of pediatric resuscitation.

1. Recognition of Pre-Arrest States

Clinicians must rapidly distinguish between mild/moderate distress and physiological failure to prevent progression to cardiopulmonary arrest:

Respiratory Distress vs. Respiratory Failure

• Respiratory Distress: Characterized by increased work of breathing (tachypnea, retractions, nasal flaring, grunting, accessory muscle use) while maintaining adequate gas exchange (normal mental status, clear breath sounds, normal skin color).
• Respiratory Failure: Characterized by inadequate oxygenation and/or ventilation. Signs include bradypnea or irregular respirations, gasping, diminished breath sounds, cyanosis, and progressive lethargy or obtundation due to hypercapnia and hypoxia. Immediate airway intervention is mandatory.

Compensated vs. Hypotensive Shock

• Compensated Shock: Systemic perfusion is maintained through compensatory mechanisms (tachycardia, peripheral vasoconstriction, delayed capillary refill >2 seconds, cool extremities). Blood pressure remains within normal limits.
• Hypotensive Shock: Compensatory mechanisms fail, resulting in systemic hypotension. This is a medical emergency indicating imminent cardiac arrest. Hypotension is defined as a systolic blood pressure below the 5th percentile for age:
  • Neonates (0-28 days): <60 mmHg
  • Infants (1-12 months): <70 mmHg
  • Children (1-10 years): <70 mmHg + (2 Г— Age in years)
  • Children (>10 years): <90 mmHg

2. Advanced Airway Management & Equipment Sizing

Correct equipment sizing is vital to prevent airway trauma and guarantee adequate ventilation. Standard pediatric tube sizes can be calculated using age-based formulas:

Endotracheal Tube (ETT) Selection Formulas

• Uncuffed ETT Size (ID mm): (Age in years / 4) + 4
• Cuffed ETT Size (ID mm): (Age in years / 4) + 3.5

Airway Equipment Quick-Reference Guide

Age / Weight Range	Broselow Color	ETT Size (Cuffed)	Laryngoscope Blade (Size/Type)	Suction Catheter (Fr)
Neonate (3-5 kg)	Grey	3.0 mm cuffed	Size 0 or 1 Miller (Straight)	6 - 8 Fr
Infant (6-7 kg)	Pink	3.5 mm cuffed	Size 1 Miller (Straight)	8 Fr
Toddler (10-11 kg)	Purple	4.0 mm cuffed	Size 1 Miller or Mac (Curved)	8 - 10 Fr
Child (15-18 kg)	Blue	4.5 mm cuffed	Size 2 Miller or Mac	10 Fr
Adolescent (>35 kg)	Green / White	6.0 - 7.0 mm cuffed	Size 3 Mac	12 Fr

3. PALS Pharmacological Reference

All emergency drugs in pediatric resuscitation are strictly dosed based on weight (mg/kg) to avoid critical toxicity or under-dosing. Vascular access (IV/IO) must be established rapidly.

Medication	Indication	Standard Dosage	Clinical Notes
Epinephrine (Adrenaline)	Asystole, Pulseless VT/VF, Bradycardia	0.01 mg/kg IV/IO (0.1 mL/kg of 0.1 mg/mL)	Repeat every 3-5 minutes during arrest.
Amiodarone	Refractory VF / Pulseless VT	5 mg/kg bolus IV/IO	May repeat up to 3 times for refractory arrest (Max 300 mg).
Lidocaine	Refractory VF / Pulseless VT (Alternative)	1 mg/kg loading dose IV/IO	Maintenance infusion: 20-50 mcg/kg/min.
Adenosine	Supraventricular Tachycardia (SVT)	0.1 mg/kg rapid IV push (Max 6 mg)	Second dose: 0.2 mg/kg rapid IV (Max 12 mg). Run with immediate flush.
Atropine Sulfate	Symptomatic Bradycardia	0.02 mg/kg IV/IO (Min 0.1 mg, Max 0.5 mg)	Useful for high vagal tone or primary AV block.

4. Electrical Therapy (Defibrillation & Cardioversion)

During arrest rhythms, early defibrillation is critical for shockable pathways (Ventricular Fibrillation and Pulseless Ventricular Tachycardia):

• Defibrillation (VF/Pulseless VT): First dose is 2 J/kg. Second dose is 4 J/kg. Subsequent doses should be ≥4 J/kg, up to a maximum of 10 J/kg or the adult equivalent.
• Synchronized Cardioversion (Unstable SVT/VT with Pulse): Dose is 0.5 to 1 J/kg. If unsuccessful, increase to 2 J/kg.