Pediatric Hypovolemic Shock

Introduction to Pediatric Hypovolemic Shock

Hypovolemic shock is a life-threatening condition characterized by insufficient tissue perfusion due to decreased intravascular volume. In children, it represents a significant emergency requiring prompt recognition and intervention.

Key Points

Most common type of shock in pediatric population
Leading cause of pediatric mortality worldwide
Common causes: Dehydration, hemorrhage, burns, trauma
Children can compensate well initially but decompensate rapidly
Early recognition and aggressive management are crucial for survival

Pathophysiology

Compensatory Mechanisms

Sympathetic Response:
Increased catecholamine release leads to:
- Vasoconstriction of non-essential vascular beds
- Increased heart rate and contractility
- Blood flow redistribution to vital organs
Hormonal Response:
Activation of renin-angiotensin-aldosterone system:
- Increased sodium and water retention
- Vasoconstriction through angiotensin II
- ADH release for water conservation

Stages of Shock

Compensated Shock:
Vital organ perfusion maintained through compensatory mechanisms
Decompensated Shock:
Failure of compensatory mechanisms leading to organ dysfunction
Irreversible Shock:
Cellular death and organ failure despite intervention

Clinical Presentation

Early Signs (Compensated)

Mental Status: Anxious, irritable, or agitated
Vital Signs:
- Tachycardia (earliest sign)
- Normal blood pressure
- Tachypnea
- Normal or slightly elevated temperature
Skin Signs:
- Cool extremities
- Prolonged capillary refill (>2 seconds)
- Pale skin

Late Signs (Decompensated)

Mental Status: Lethargic, confused, or unconscious
Vital Signs:
- Hypotension
- Weak or absent peripheral pulses
- Bradycardia (very late sign)
Other Signs:
- Decreased urine output (<1ml/kg/hr)
- Mottled skin
- Weak central pulses

Diagnosis

Initial Assessment

Primary Survey (ABC):
- Airway patency
- Breathing pattern and effort
- Circulation assessment (pulses, perfusion)
Volume Loss Estimation:
- Mild: 3-5% loss
- Moderate: 6-9% loss
- Severe: ≥10% loss

Laboratory Studies

Immediate Studies:
- Complete blood count
- Basic metabolic panel
- Blood gas analysis
- Coagulation profile
- Lactate level
- Type and cross-match
Additional Studies:
- Liver function tests
- Troponin (if cardiac involvement suspected)
- Blood cultures (if infection suspected)

Imaging

Chest X-ray
FAST scan in trauma
Point-of-care ultrasound for IVC assessment

Management

Immediate Interventions

Vascular Access:
- Two large-bore IV lines
- Consider intraosseous access if IV access fails
- Central line placement if necessary
Fluid Resuscitation:
- Initial bolus: 20mL/kg isotonic crystalloid
- Reassess after each bolus
- May need up to 60mL/kg in first hour
- Consider blood products if hemorrhagic shock

Specific Management Based on Cause

Hemorrhagic Shock:
- Blood products (1:1:1 ratio)
- Damage control surgery if needed
- Tranexamic acid consideration
Dehydration:
- Calculate maintenance needs
- Replace ongoing losses
- Correct electrolyte imbalances
Burns:
- Parkland formula for fluid replacement
- Monitor urine output closely
- Consider albumin after 24 hours

Complications

Early Complications

Organ Dysfunction:
- Acute kidney injury
- Respiratory failure
- Metabolic acidosis
Coagulopathy
Electrolyte imbalances

Late Complications

Multiple organ dysfunction syndrome
Neurological sequelae
Chronic kidney disease

Monitoring & Follow-up

Clinical Monitoring

Vital Signs:
- Continuous heart rate monitoring
- Blood pressure every 5-15 minutes
- Continuous pulse oximetry
- Temperature monitoring
End-organ Perfusion:
- Urine output (target >1mL/kg/hr)
- Mental status
- Capillary refill
- Skin temperature

Treatment Response Indicators

Normalization of vital signs
Improved mental status
Warm extremities
Normal capillary refill
Adequate urine output