4 Pediatric Shock

Recognize impaired perfusion

Shock is an emergency caused by inadequate tissue perfusion: oxygen and nutrients are not reaching the body's tissues sufficiently. Recognize it from the child's overall perfusion and its changes over time, rather than relying on blood pressure alone.

Children can maintain blood pressure through compensatory increases in heart rate and vascular tone. As a result, normal blood pressure does not rule out shock. Hypotension is a late, dangerous sign; act when perfusion is worsening rather than waiting for blood pressure to fall.

Compare shock stages

In compensated shock, the heart rate and breathing are usually fast. The child may have weak peripheral pulses, cool, pale, or mottled skin, delayed capillary refill, irritability, anxiety, or reduced interaction; urine output may fall. Blood pressure may still be normal for age.

In decompensated shock, the heart rate may become markedly fast, and breathing may be slow or irregular late in the course. Peripheral pulses may be absent and central pulses weak; skin may be cold and mottled. Low blood pressure for age, lethargy, confusion or reduced consciousness, and very little or no urine are concerning signs. Bradycardia can also occur late.

Patterns vary. In distributive shock, including early septic shock, the skin may be warm, pulses bounding, and capillary refill brisk rather than delayed. No single sign reliably excludes shock. Assess the whole child and repeat observations.

Assess the child and track changes

Use an age-appropriate ABCDE assessment while looking for and treating immediately reversible threats. Check and trend the child's appearance and mental status, circulation, breathing and oxygenation, and urine output.

Assess alertness, interaction, irritability, lethargy, or confusion. For circulation, check heart rate, blood pressure, central and peripheral pulse strength, skin color and temperature, and capillary refill; compare peripheral pulses with central pulses. To check capillary refill, press briefly on a fingertip or sternum and note how quickly color returns. Refill longer than about $2$ seconds can indicate impaired perfusion, but interpret it alongside temperature, lighting, and other findings.

Check respiratory rate and effort, oxygen saturation, and lung sounds. Fast breathing can reflect distress or metabolic acidosis. Falling urine output suggests impaired organ perfusion; obtain a measured output when feasible.

Interpret blood pressure by age

A common PALS screening threshold for systolic hypotension is:

• Infants: below $70\,\text{mm Hg}$.

• Children aged $1$–$10$ years: below $70 + 2 \times \text{age in years}\,\text{mm Hg}$.

• Children older than $10$ years: below $90\,\text{mm Hg}$.

Use local age-specific references and an appropriately sized cuff. These thresholds identify hypotension, not early shock.

Stabilize and reassess

Activate the appropriate resuscitation response, provide continuous monitoring, and reassess frequently. Support airway and breathing; give oxygen for hypoxemia or significant respiratory compromise. Obtain IV access promptly, using intraosseous access if needed in a critically ill child.

Check bedside glucose and correct hypoglycemia. Obtain investigations, such as lactate when sepsis is suspected, without delaying resuscitation or treatment of the cause.

Give fluids according to the likely cause and reassess after every bolus. In septic shock, guidance supports isotonic crystalloid in aliquots of $10$–$20\,\text{mL/kg}$, with repeated assessment for improved perfusion and fluid overload. Total-volume approaches differ depending on whether intensive care is available; follow local protocols rather than treating a maximum volume as a target. Stop boluses if shock resolves or signs of overload appear.

Treat according to the cause

Treatment depends on the likely mechanism; fluids alone will not correct every type of shock.

• Possible hemorrhagic shock after trauma: Control external bleeding and activate the trauma and blood-product pathway early. For hypotensive traumatic hemorrhagic shock, blood products are preferred over continued crystalloid when available.

• Possible cardiogenic shock or fluid overload: Crackles, an enlarged liver, or worsening respiratory distress call for urgent expert input and caution with fluid boluses.

• Septic shock: Give appropriate antimicrobials promptly and address the infection source. If hypoperfusion persists despite fluid, or more fluid is unsafe, seek urgent critical-care support for vasoactive treatment.

• Other causes: Treat the mechanism promptly, such as anaphylaxis or an obstructive emergency.

Bring the assessment together

Tachycardia, altered behavior, weak pulses, abnormal skin temperature or color, delayed or brisk capillary refill, and reduced urine output should prompt urgent assessment. Falling blood pressure, weak central pulses, bradycardia, and reduced consciousness suggest decompensation.

Recognize shock by impaired perfusion, stabilize airway and breathing, establish access, treat the cause, and reassess after every intervention—especially each fluid bolus.