Introduction to Pediatric Septic Shock

Septic shock in pediatrics represents a severe subset of sepsis characterized by profound circulatory, cellular, and metabolic abnormalities associated with a higher risk of mortality than sepsis alone.

Key Points

• Time-critical emergency requiring immediate recognition and intervention
• Leading cause of death in children worldwide
• Mortality rates vary from 10% to 40% depending on resources and setting
• Early recognition and adherence to protocol-driven care significantly improve outcomes
• Different pathophysiology and clinical presentation compared to adults

Pathophysiology

Key Mechanisms

• Inflammatory Response:
  • Massive cytokine release (cytokine storm)
  • Activation of complement cascade
  • Endothelial dysfunction
  • Microvascular thrombosis
• Hemodynamic Changes:
  • Initial hyperdynamic (warm) phase:
    • Increased cardiac output
    • Decreased systemic vascular resistance
    • Warm extremities
  • Late hypodynamic (cold) phase:
    • Decreased cardiac output
    • Increased systemic vascular resistance
    • Poor peripheral perfusion

Cellular Dysfunction

• Mitochondrial Dysfunction:
  • Impaired oxygen utilization
  • Cellular energy failure
  • Increased lactate production
• Endothelial Injury:
  • Capillary leak syndrome
  • Tissue edema
  • Organ dysfunction

Risk Factors & Epidemiology

High-Risk Populations

• Age-related:
  • Neonates and infants < 1 year
  • Premature infants
  • Adolescents with chronic conditions
• Underlying Conditions:
  • Immunocompromised states
  • Chronic medical conditions
  • Recent surgery or invasive procedures
  • Malignancy
  • Congenital heart disease

Common Causative Organisms

• Bacteria:
  • N. meningitidis
  • S. pneumoniae
  • Group B Streptococcus (in neonates)
  • Gram-negative organisms
• Viruses:
  • Influenza
  • RSV
  • COVID-19
• Fungi:
  • Candida species
  • Aspergillus (in immunocompromised)

Clinical Presentation

Early Recognition Signs

• Temperature Abnormalities:
  • Fever (>38.5°C) or hypothermia (<36°C)
  • Temperature instability
• Cardiovascular:
  • Tachycardia
  • Flash capillary refill
  • Bounding pulses (early)
  • Wide pulse pressure
• Respiratory:
  • Tachypnea
  • Increased work of breathing
  • Oxygen requirement

Late Signs

• Cardiovascular:
  • Hypotension
  • Poor peripheral perfusion
  • Weak pulses
  • Narrow pulse pressure
• Mental Status:
  • Lethargy
  • Confusion
  • Decreased responsiveness
• Organ Dysfunction:
  • Oliguria
  • Metabolic acidosis
  • Elevated lactate
  • Coagulopathy

Diagnosis

Initial Workup

• Blood Studies:
  • Complete blood count with differential
  • Blood cultures (before antibiotics)
  • Basic metabolic panel
  • Coagulation profile
  • Blood gas analysis
  • Lactate level
• Inflammatory Markers:
  • C-reactive protein
  • Procalcitonin
  • ESR
• Source Identification:
  • Urine culture
  • CSF studies if indicated
  • Respiratory cultures
  • Site-specific cultures based on clinical suspicion

Imaging

• Chest X-ray
• Point-of-care ultrasound
• CT scan (if source identification needed)
• Echocardiogram (if cardiac dysfunction suspected)

Management

First Hour Bundle

• Recognition and Vascular Access:
  • Establish IV/IO access within 5 minutes
  • Draw blood cultures
  • Start continuous monitoring
• Fluid Resuscitation:
  • 20mL/kg boluses of crystalloid
  • Reassess after each bolus
  • Up to 60mL/kg or more if needed
  • Consider balanced solutions
• Antimicrobial Therapy:
  • Broad-spectrum antibiotics within 1 hour
  • Consider local resistance patterns
  • Add antifungal if indicated

Ongoing Management

• Hemodynamic Support:
  • Vasoactive medications if fluid-refractory
  • Epinephrine for cold shock
  • Norepinephrine for warm shock
  • Consider stress-dose hydrocortisone
• Respiratory Support:
  • Oxygen therapy
  • Early intubation if needed
  • Lung-protective ventilation
• Source Control:
  • Identify and control infection source
  • Surgical intervention if needed
  • Remove infected devices

Complications

Acute Complications

• Organ Dysfunction:
  • Acute kidney injury
  • Acute respiratory distress syndrome
  • Liver dysfunction
  • Myocardial depression
• Hematologic:
  • DIC
  • Thrombocytopenia
  • Bleeding complications
• Metabolic:
  • Severe acidosis
  • Electrolyte imbalances
  • Hyperglycemia

Long-term Complications

• Post-sepsis syndrome
• Neurocognitive impairment
• Chronic organ dysfunction
• Growth and development issues

Prognosis & Follow-up

Monitoring Parameters

• Clinical Markers:
  • Hemodynamic stability
  • Organ function recovery
  • Resolution of fever
  • Improved mental status
• Laboratory Markers:
  • Trending lactate levels
  • Inflammatory markers
  • Organ function tests

Long-term Follow-up

• Regular developmental assessment
• Monitoring for chronic complications
• Psychological support
• Rehabilitation services if needed