Overview
Definition:
Septic shock in children is a life-threatening condition characterized by circulatory, cellular, and metabolic abnormalities associated with sepsis, leading to persistent hypotension requiring vasopressor therapy to maintain a mean arterial pressure (MAP) ≥ 65 mmHg or an age-appropriate low normal MAP, and a serum lactate level ≥ 2 mmol/L after initial fluid resuscitation
Lactate clearance is a critical marker of tissue perfusion and oxygenation during resuscitation.
Epidemiology:
Sepsis is a leading cause of mortality and morbidity in pediatric intensive care units globally
Incidence varies by region and healthcare setting, but it remains a significant concern
Neonatal sepsis has a higher incidence and mortality than in older children
Risk factors include prematurity, immunocompromise, invasive devices, and underlying chronic illnesses.
Clinical Significance:
Adequate lactate clearance is a surrogate marker for successful resuscitation and improved tissue perfusion in septic shock
Failure to achieve target lactate levels is associated with increased organ dysfunction, higher mortality rates, and longer ICU stays
Prompt recognition and effective management guided by lactate clearance are crucial for pediatric patients.
Clinical Presentation
Symptoms:
Fever or hypothermia
Lethargy or irritability
Poor feeding or vomiting
Tachypnea or grunting
Hypotension (may be a late sign)
Decreased urine output
Mottled skin or cyanosis.
Signs:
Altered mental status
Tachycardia or bradycardia
Hypotension (MAP < 65 mmHg or age-appropriate low normal)
Cool extremities
Poor capillary refill (>2 seconds)
Mottled or cyanotic skin
Oliguria or anuria
Respiratory distress.
Diagnostic Criteria:
Diagnosis of septic shock in children is based on the presence of sepsis (suspected or documented infection plus systemic signs of organ dysfunction, often using criteria like SOFA or qSOFA adapted for pediatrics) with persistent hypotension despite adequate fluid resuscitation and elevated lactate levels (≥ 2 mmol/L)
Age-appropriate MAP targets are crucial for diagnosis.
Diagnostic Approach
History Taking:
Detailed history of recent infections, fever, immunization status, underlying comorbidities (e.g., immunocompromise, cardiac disease), recent travel, antibiotic use, and exposure to sick individuals
Acute onset of symptoms is typical.
Physical Examination:
Assess vital signs (heart rate, respiratory rate, blood pressure, temperature, oxygen saturation)
Perform a thorough systemic examination focusing on signs of poor perfusion (capillary refill, skin temperature, peripheral pulses), mental status, respiratory effort, and abdominal tenderness
Evaluate for potential sources of infection.
Investigations:
Complete blood count with differential and peripheral smear
Blood cultures (at least two sets from different sites before antibiotics)
Serum lactate
Blood gas analysis (venous or arterial) to assess acid-base status
Renal and liver function tests
C-reactive protein (CRP) and procalcitonin may aid in infection diagnosis
Urine analysis and culture
Imaging (chest X-ray, ultrasound, CT scan) to identify infection source.
Differential Diagnosis:
Non-infectious causes of hypotension and shock, including hypovolemic shock (e.g., dehydration, hemorrhage), cardiogenic shock (e.g., myocarditis, congenital heart disease), obstructive shock (e.g., tension pneumothorax, cardiac tamponade), and anaphylactic shock
Distinguishing features include the presence of infection, systemic inflammatory response, and organ dysfunction in septic shock.
Management
Initial Management:
Immediate resuscitation is paramount
Administer intravenous fluid boluses of crystalloids (e.g., 0.9% Normal Saline or Lactated Ringer's) at 20 mL/kg over 5-20 minutes, repeated as needed based on clinical response (perfusion, urine output, MAP)
If hypotension persists despite adequate fluid resuscitation, initiate vasopressor therapy (e.g., norepinephrine) to maintain MAP
Oxygen supplementation is essential.
Lactate Clearance Goals:
The primary goal is to achieve a reduction in lactate levels by at least 20% within the first 2 hours of resuscitation and to normalize lactate levels (< 2 mmol/L) by 6-12 hours
Persistent elevated lactate levels beyond 12 hours are associated with worse outcomes
Serial lactate measurements are critical for monitoring response to therapy.
Medical Management:
Empirical broad-spectrum antibiotic therapy should be initiated as soon as possible after blood cultures are obtained, ideally within 1 hour of recognition of sepsis or septic shock
Antibiotic choice depends on the suspected source of infection, local resistance patterns, and patient factors
Vasopressors, primarily norepinephrine, are used to support blood pressure if hypotension persists after fluid resuscitation
Other vasopressors like dopamine or epinephrine may be considered
Corticosteroids may be considered in refractory shock.
Supportive Care:
Mechanical ventilation if respiratory failure develops
Nutritional support via enteral feeding when feasible
Strict monitoring of vital signs, fluid balance, urine output, and neurological status
Glucose control
Deep vein thrombosis prophylaxis
Stress ulcer prophylaxis
Regular reassessment of perfusion and organ function.
Complications
Early Complications:
Acute kidney injury
Acute respiratory distress syndrome (ARDS)
Disseminated intravascular coagulation (DIC)
Multi-organ dysfunction syndrome (MODS)
Hypoglycemia
Hypothermia or hyperthermia
Hypoglycemia.
Late Complications:
Post-intensive care syndrome (PICS), including neurocognitive deficits, muscle weakness, and psychological sequelae
Chronic kidney disease
Growth and developmental delays
Increased susceptibility to infections.
Prevention Strategies:
Early recognition and prompt, aggressive resuscitation
Strict adherence to sepsis bundles
Judicious use of invasive devices
Infection control measures
Early initiation of appropriate antibiotics
Close monitoring for signs of organ dysfunction.
Prognosis
Factors Affecting Prognosis:
Severity of illness at presentation
Time to initiation of appropriate antibiotics and resuscitation
Presence of comorbidities
Development of organ dysfunction
Response to treatment, particularly lactate clearance
Age (neonates and very young infants have worse outcomes).
Outcomes:
Mortality rates for pediatric septic shock can range from 5-30% or higher, depending on the factors mentioned above
Survivors may experience significant morbidity and require long-term follow-up
Early and effective management significantly improves the chances of survival and reduces long-term sequelae.
Follow Up:
Patients who have recovered from septic shock require comprehensive follow-up care, including assessment of growth and development, neurocognitive function, cardiac function, and renal function
Rehabilitation services may be beneficial for children with significant PICS
Regular well-child visits are crucial.
Key Points
Exam Focus:
Lactate clearance is a critical marker of resuscitation success in pediatric septic shock
Target: ≥ 20% reduction in lactate in 2 hours, normalization (< 2 mmol/L) by 6-12 hours
Hypotension definition includes age-appropriate MAP
Prompt antibiotics (within 1 hour) and fluid resuscitation are cornerstones.
Clinical Pearls:
Don't underestimate the sick child
early recognition is key
Reassess perfusion frequently and adjust management based on clinical signs and lactate trends
Use age-appropriate MAP targets for diagnosis and management
Lactate clearance is more informative than a single lactate value.
Common Mistakes:
Delaying antibiotics
Inadequate fluid resuscitation
Not titrating vasopressors appropriately to achieve target MAP
Forgetting to recheck lactate and perfusion parameters
Misinterpreting hypotension in infants (normal MAP is higher than in adults).