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Pediatric Resuscitation: PALS, Shock & Arrhythmias

Name: Pediatric Resuscitation: PALS, Shock & Arrhythmias
Creator: Veli Bakalov, MD

Spot shock before the pressure falls, then run arrest, sepsis, and arrhythmias by weight.

Pediatrics·Infectious Disease & Emergencies·7 min read·9 high-yield points·Reviewed by Veli Bakalov, MD @HemeOncBuddy

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Pediatric assessment triangle (appearance, work of breathing, circulation to skin) is a hands-off, 30-second sick-or-not-sick check; abnormal appearance plus skin = shock.
Hypotension is late: SBP <70 + (2 × age in years) for ages 1–10; tachycardia and capillary refill >2 s mark compensated shock.
Pediatric arrest is usually hypoxic (bradycardia → asystole/PEA), so ventilate early; compress one-third of AP depth at 100–120/min, 15:2 with two rescuers.
Arrest doses: epinephrine 0.01 mg/kg IV/IO every 3–5 min; defibrillation 2 J/kg then 4 J/kg; amiodarone 5 mg/kg or lidocaine 1 mg/kg for refractory VF.
If an IV is not placed quickly, use intraosseous access in the proximal tibia; dose by length-based tape, not a guessed weight.
Septic shock: 10–20 mL/kg isotonic boluses up to 40–60 mL/kg with reassessment, stop for hepatomegaly or crackles, antibiotics within 1 hour, check glucose.
Fluid-refractory septic shock: epinephrine or norepinephrine (not dopamine), peripherally if needed; hydrocortisone if catecholamine-resistant.
Bradycardia with poor perfusion: oxygenate and ventilate first, CPR if HR <60, epinephrine; atropine only for vagal tone or primary AV block.
Infant SVT (HR >220, narrow QRS, no P waves): ice to face → adenosine 0.1 mg/kg rapid push → synchronized cardioversion 0.5–1 J/kg if unstable; no verapamil under 1 year.

Rapid assessment: recognizing the sick child

Pediatric assessment triangle. A 30-second, hands-off look from the doorway. Appearance (tone, interactiveness, consolability, look or gaze, speech or cry) is the best window on brain oxygenation and perfusion; a limp child who ignores a stranger is sick until proven otherwise. Work of breathing covers abnormal sounds (stridor, grunting, wheeze) and visible effort (retractions, flaring, head bobbing, tripoding). Circulation to skin means pallor, mottling, or cyanosis.

Work of breathing alone → respiratory distress; plus abnormal appearance → respiratory failure.
Appearance + circulation → shock.
Appearance alone → brain or metabolic problem (hypoglycemia, toxin, head injury, postictal state).
All three → cardiopulmonary failure: start resuscitation.

Compensated shock. Children hold blood pressure with tachycardia and vasoconstriction, so early shock shows a fast heart rate, capillary refill >2 seconds, cool mottled extremities, weak distal pulses, low urine output, and irritability or lethargy with a normal BP. Tachycardia is the earliest, most sensitive (but nonspecific) sign. Hypotension means decompensation, and arrest may be minutes away.

Systolic pressure defining hypotension

Age	Hypotension if SBP is
Term neonate (0–28 days)	<60 mm Hg
Infant (1–12 months)	<70 mm Hg
Child 1–10 years	<70 + (2 × age in years) mm Hg
Older than 10 years	<90 mm Hg

Not all shock wants fluid. Hypovolemia (gastroenteritis, hemorrhage) is the most common type. Cardiogenic shock (myocarditis, cardiomyopathy) brings hepatomegaly, crackles, and a gallop and needs small 5–10 mL/kg boluses over 10–20 minutes plus inotropes. Obstructive shock (tension pneumothorax, tamponade, a closing ductus in a 1–2-week-old) needs the obstruction relieved, including prostaglandin E1 for a ductal-dependent lesion.

Cardiac arrest and CPR

Why children arrest. Most pediatric arrests end a slide from respiratory failure or shock, so the first rhythm is usually bradycardia deteriorating to asystole or PEA. VF or pulseless VT is uncommon and suggests a primary cardiac event such as sudden collapse in sport (commotio cordis, hypertrophic cardiomyopathy, long QT). Airway, oxygen, and ventilation therefore come first; bag-mask ventilation is a reasonable alternative to prehospital intubation. A child with a pulse but inadequate breathing gets 1 breath every 2–3 seconds (20–30/min).

Compressions. At least one-third of the anteroposterior chest depth (about 4 cm in infants, 5 cm in children), 100–120/min, full recoil, minimal pauses. Ratio 30:2 for a lone rescuer and 15:2 with two rescuers for infants and children up to puberty (newborn resuscitation uses 3:1). Two-rescuer infant CPR uses the two-thumb–encircling hands technique on the lower sternum. With an advanced airway, compressions are continuous with 1 breath every 2–3 seconds.

Access and dosing. If a peripheral IV is not placed quickly, insert an intraosseous needle into the anteromedial proximal tibia just below the tibial tuberosity (alternatives: distal femur, distal tibia, proximal humerus); any drug, fluid, or blood product can be given IO at IV doses. Avoid a fractured or previously punctured bone, overlying infection or burn, and brittle-bone disease (osteogenesis imperfecta, osteopetrosis). A length-based tape (Broselow) converts measured length into an estimated weight with color-coded doses and equipment sizes for children up to about 36 kg. Cuffed endotracheal tube size ≈ age/4 + 3.5 mm.

Start CPROxygen, attach the monitor/defibrillator, identify the rhythm.
VF or pulseless VT: shock 2 J/kgResume CPR for 2 minutes at once; obtain IV or IO access.
Shock 4 J/kgCPR 2 minutes; epinephrine 0.01 mg/kg every 3–5 minutes.
Shock ≥4 J/kg (max 10 J/kg or adult dose)CPR 2 minutes; amiodarone 5 mg/kg or lidocaine 1 mg/kg.

Asystole or PEA. Continue CPR with rhythm checks every 2 minutes and give epinephrine as early as possible: 0.01 mg/kg IV/IO (0.1 mL/kg of 0.1 mg/mL, max 1 mg) every 3–5 minutes. The endotracheal dose, used only without IV/IO access, is 0.1 mg/kg.

Search for reversible causes. H's: hypoxia, hypovolemia, hydrogen ion (acidosis), hypo- or hyperkalemia, hypothermia, hypoglycemia. T's: tension pneumothorax, tamponade, toxins, thrombosis.

Septic shock: the first hour

Recognize and accessFever or hypothermia with tachycardia, altered mentation, and poor perfusion; place two IV or IO lines and draw cultures, lactate, glucose, and ionized calcium.
FluidIsotonic crystalloid (balanced solution or normal saline) in 10–20 mL/kg boluses, up to 40–60 mL/kg in the first hour, reassessing after each. Stop for new hepatomegaly, crackles, gallop, or rising work of breathing.
Antibiotics within 1 hourCultures must never delay them; e.g., ceftriaxone plus vancomycin in a previously healthy child.
Glucose and calciumInfants have scant glycogen: treat hypoglycemia with dextrose 0.5 g/kg (D10 at 5 mL/kg).
Vasoactive infusionEpinephrine or norepinephrine, not dopamine, for fluid-refractory shock; start peripherally or IO while central access is placed.
Refractory shockStress-dose hydrocortisone for catecholamine-resistant shock or adrenal risk (chronic steroids, CAH).

Cold vs warm shock. Cold shock (cool, mottled skin, capillary refill >2 s, narrow pulse pressure) reflects low output and suits epinephrine's inotropy. Warm shock (flushed skin, flash capillary refill, bounding pulses, wide pulse pressure) reflects vasodilation and suits norepinephrine.

Rule of 50: dextrose % × mL/kg = 50, so D10 at 5 mL/kg or D25 at 2 mL/kg gives 0.5 g/kg; D10 is preferred in infants.

Where intensive care is unavailable, boluses in children who were not hypotensive increased mortality (FEAST trial); give maintenance fluid instead.

Bradycardia with poor perfusion

Hypoxia first. Bradycardia in a sick child is hypoxia until proven otherwise and signals impending arrest. Open the airway, give 100% oxygen, and bag-mask ventilate. If the heart rate stays <60/min with poor perfusion despite effective ventilation, start compressions and give epinephrine 0.01 mg/kg every 3–5 minutes.

Atropine and pacing. Atropine 0.02 mg/kg is for increased vagal tone (intubation, suctioning) or primary AV block. Pacing is for complete heart block unresponsive to drugs, such as congenital block from maternal anti-Ro/SSA antibodies or block after cardiac surgery. Also consider raised intracranial pressure (Cushing triad: hypertension, bradycardia, irregular respirations), hypothermia, and toxins (β-blockers, calcium channel blockers, digoxin, clonidine).

Atropine does not fix hypoxia: a bradycardic child who is not being ventilated needs breaths before drugs.

Tachyarrhythmias: SVT and WPW

Supraventricular tachycardia is the most common symptomatic tachyarrhythmia in children. Infants present with poor feeding, irritability, pallor, sweating, and tachypnea; SVT lasting hours to days causes heart failure with hepatomegaly and crackles. Older children report sudden palpitations or chest discomfort.

SVT vs sinus tachycardia

Feature	SVT	Sinus tachycardia
Rate	Usually >220 (infant), >180 (child); fixed	Usually below those limits; varies with crying, activity, fever
P waves	Absent or retrograde	Present, upright in I and aVF
QRS	Narrow (≤0.09 s)	Narrow
Onset	Abrupt start and stop	Gradual
History	Vague; nonspecific feeding problems	Fever, dehydration, pain, blood loss

Stable SVT. Vagal maneuvers first: a bag of ice water on the infant's face (diving reflex) without covering the airway, or Valsalva in older children; never ocular pressure. Then adenosine 0.1 mg/kg (max 6 mg) by rapid push through the port closest to the heart with an immediate saline flush, repeating at 0.2 mg/kg (max 12 mg).

Unstable SVT (hypotension, altered mental status, shock): synchronized cardioversion at 0.5–1 J/kg, increasing to 2 J/kg. Adenosine may be tried first only if IV access is already in place and it will not delay cardioversion.

Avoid verapamil in infants younger than 1 year: it can cause profound hypotension, bradycardia, and asystole.

Wolff-Parkinson-White. Accessory-pathway reentry drives most infant SVT, while AV nodal reentry becomes more common in adolescents. In sinus rhythm WPW shows a short PR interval, a delta wave, and a widened QRS; it is associated with Ebstein anomaly. In pre-excited atrial fibrillation, AV-nodal blockers (adenosine, digoxin, verapamil) can speed conduction down the pathway and trigger VF, so use procainamide or cardioversion. Many infants outgrow SVT in the first year; catheter ablation is definitive for recurrent SVT or WPW in older children. A wide-complex tachycardia is treated as VT: synchronized cardioversion if a pulse is present with poor perfusion, defibrillation if pulseless.