34  Sepsis in Children

Author

Prof Anthony Enimil

Published

May 25, 2025

34.1 Definition

Sepsis is a life-threatening condition characterized by organ dysfunction resulting from a dysregulated host response to infection. In children, it presents a range of disorders caused by bacterial, viral, fungal, or parasitic infections. Septic shock, a severe form of sepsis, is defined by persistent hypotension that requires vasopressors to maintain a mean arterial pressure (MAP) of ≥ 65 mmHg and a serum lactate level greater than 2 mmol/L, despite adequate fluid resuscitation.

34.2 Incidence and Prevalence

Sepsis continues to be a major cause of morbidity and mortality in children around the globe. As stated by the World Health Organization (WHO), sepsis plays a significant role in childhood mortality, especially in low-resource environments. The incidence varies by region, with higher rates observed in neonates and infants due to their immature immune systems.

34.3 Aetiology

Sepsis can result from infections caused by bacteria, viruses, fungi, and parasites. The most common bacterial pathogens vary by age:

  • Early-Onset Neonatal Sepsis: Streptococcus agalactiae, Escherichia coli, Haemophilus influenzae, Listeria monocytogenes.
  • Infant Sepsis: Haemophilus influenzae type b (Hib), Streptococcus pneumoniae, Neisseria meningitidis, Salmonella species.
  • Late-Onset Neonatal Sepsis: Staphylococcus aureus, E. coli, Klebsiella species, Pseudomonas aeruginosa, Candida species.

34.4 Pathogenesis

Sepsis results from a dysregulated immune response to infection, leading to widespread tissue injury. The process involves:

  1. Immune Dysregulation: Excessive release of pro-inflammatory and anti-inflammatory mediators.
  2. Microcirculatory Derangements: Increased vascular permeability, leading to hypotension and organ dysfunction.
  3. End-Organ Damage: Progression to multi-organ failure due to poor perfusion.

34.5 Signs and Symptoms

Early recognition is crucial, as sepsis can progress rapidly. Symptoms include:

  • Fever or Hypothermia
  • Tachycardia and Tachypnea
  • Altered Mental Status
  • Hypotension
  • Cool Extremities
  • Petechial or Purpuric Rash (suggestive of meningococcal sepsis)
  • Oliguria or Anuria (kidney dysfunction).

34.6 Investigations

A thorough laboratory workup is essential for diagnosis:

  • Blood Tests: Complete Blood Count (CBC), Blood Culture, Blood Gas Analysis (including lactate levels).
  • Urine Analysis: Dipstick, Routine Examination, Culture.
  • Cerebrospinal Fluid (CSF) Analysis: Culture and Sensitivity.
  • Coagulation Studies: To assess disseminated intravascular coagulation (DIC).
  • Inflammatory Markers: C-Reactive Protein (CRP), Procalcitonin (PCT), Interleukins (IL-1b, IL-6, IL-8), Tumor Necrosis Factor-alpha.

34.7 Treatment

Early antibiotic therapy and fluid resuscitation are critical:

  • Empirical Broad-Spectrum Antibiotics: Based on suspected pathogens.
  • Fluid Resuscitation: Crystalloids (e.g., normal saline or Ringer’s lactate).
  • Vasopressors: If hypotension persists despite fluids.
  • Supportive Care: Oxygen therapy, mechanical ventilation, renal replacement therapy if needed.

34.8 Complications

Sepsis can lead to multi-organ failure and death if untreated. Common complications include:

  • Acute Respiratory Distress Syndrome (ARDS)
  • Disseminated Intravascular Coagulation (DIC)
  • Renal Failure
  • Cardiac Dysfunction
  • Neurological Sequelae (e.g., cognitive impairment post-sepsis).

34.9 Prognosis

The mortality rate varies based on early recognition and intervention. Neonatal sepsis has a higher fatality rate, especially in low-resource settings. Survivors may experience long-term complications, including neurodevelopmental delays.

34.10 Differential Diagnosis

Sepsis must be distinguished from other conditions with similar presentations:

  • Meningitis
  • Severe Pneumonia
  • Hemorrhagic Shock
  • Metabolic Disorders
  • Autoimmune Diseases.

34.11 References

  1. Bone RC. The sepsis syndrome: definition and general approach to management. Clin Chest Med. 1996 Jun;17(2):175-81. Available here.
  2. Angus DC, van der Poll T. Severe sepsis and septic shock. N Engl J Med. 2013 Aug 29;369(9):840-51. Available here.
  3. Goldstein B, Giroir B, Randolph A; International Consensus Conference on Pediatric Sepsis. International pediatric sepsis consensus conference: definitions for sepsis and organ dysfunction in pediatrics. Pediatr Crit Care Med. 2005 Jan;6(1):2-8. Available here

34.11.1 Clinical Scenario 1: Neonatal Sepsis

A 5-day-old male infant presents with lethargy, poor feeding, respiratory distress, and a fever of 38.5°C. On examination, the infant appears jaundiced, with cool extremities and tachypnea. The mother had a prolonged rupture of membranes (>18 hours) before delivery, and the infant had meconium-stained amniotic fluid.

Key Considerations:

  • Etiology: Early-onset neonatal sepsis, likely Streptococcus agalactiae (Group B Strep) or Escherichia coli.
  • Investigations: Blood cultures, CBC, CRP, procalcitonin, serum lactate, and lumbar puncture for CSF culture.
  • Management: Empirical IV antibiotics (Ampicillin + Gentamicin), fluid resuscitation, oxygen therapy, and supportive care.
  • Complications: Risk of meningitis and multi-organ failure if untreated.

34.11.2 Clinical Scenario 2: Pediatric Septic Shock

A 6-year-old girl presents with a history of fever (40°C) for 3 days, altered mental status, and poor urine output. She is tachycardic (HR: 150 bpm), hypotensive (BP: 75/50 mmHg), and has delayed capillary refill (>3 seconds). A petechial rash is noted on the lower extremities.

Key Considerations:

  • Etiology: Meningococcal sepsis (Neisseria meningitidis) suspected.
  • Investigations: Blood culture, CBC, coagulation studies, lactate, kidney function tests, and inflammatory markers.
  • Management: IV Ceftriaxone, aggressive fluid resuscitation, vasopressors if needed, and close monitoring in ICU.
  • Complications: Disseminated Intravascular Coagulation (DIC), Acute Respiratory Distress Syndrome (ARDS), multi-organ failure