Overview
Definition:
Shock in children is a state of inadequate tissue perfusion resulting from an imbalance between oxygen supply and demand
It is a life-threatening condition characterized by a failure of the circulatory system to maintain adequate blood flow to vital organs.
Epidemiology:
Shock is a common reason for pediatric intensive care unit admission and has a high mortality rate, especially in developing countries
Septic shock is a leading cause of mortality in children worldwide
The incidence varies based on etiology and geographic location.
Clinical Significance:
Prompt recognition and management of shock are critical to prevent irreversible organ damage and death
Understanding the different types of shock and appropriate vasoactive agent selection is paramount for successful resuscitation and improved outcomes in pediatric patients.
Clinical Presentation
Symptoms:
Irritability or lethargy
Poor feeding or vomiting
Decreased urine output
Rapid breathing or difficulty breathing
Fever or hypothermia
Cold extremities
Mottled skin.
Signs:
Hypotension (defined differently by age)
Tachycardia or bradycardia
Weak or absent peripheral pulses
Prolonged capillary refill time (>2 seconds)
Altered mental status
Cool, clammy skin (cold shock) or warm, flushed skin (warm shock)
Tachypnea
Narrow pulse pressure.
Diagnostic Criteria:
In children, hypotension is typically defined as a systolic blood pressure below the 5th percentile for age, or less than 70 mmHg plus twice the age in years (up to 12 years)
In older children and adolescents, consider <90 mmHg
However, hypotension is a late sign
look for evidence of poor perfusion.
Types Of Shock
Cold Shock:
Characterized by signs of hypoperfusion and vasoconstriction
Peripheral pulses are weak or absent, extremities are cold, and capillary refill is prolonged
Typically seen in hypovolemic, early septic (early distributive), and cardiogenic shock.
Warm Shock:
Characterized by vasodilation and hyperdynamic circulation
Peripheral pulses are bounding, skin is warm, and capillary refill may be normal or only slightly prolonged
Typically seen in established septic shock (late distributive) and anaphylactic shock
This is less common in children than cold shock.
Hypovolemic Shock:
Caused by decreased intravascular volume (e.g., dehydration from vomiting/diarrhea, hemorrhage, burns)
Presents with cold extremities, weak pulses, and hypotension.
Septic Shock:
A subset of sepsis with circulatory, cellular, and metabolic abnormalities
Often presents with a hyperdynamic state initially (warm shock) but can progress to a hypodynamic state (cold shock)
Characterized by fever/hypothermia, hypotension, and signs of hypoperfusion.
Cardiogenic Shock:
Caused by impaired cardiac function (e.g., myocarditis, congenital heart disease)
Presents with signs of poor perfusion, often with rales, hepatomegaly, and peripheral edema
Pulse pressure may be narrow.
Diagnostic Approach
History Taking:
Detailed history of present illness focusing on onset, duration, and progression of symptoms
Assess fluid intake/output, recent illnesses (fever, vomiting, diarrhea), trauma, bleeding, allergies, and cardiac history
Identify risk factors for sepsis.
Physical Examination:
Assess general appearance, mental status (AVPU scale), airway, breathing, circulation
Measure vital signs carefully, including heart rate, respiratory rate, blood pressure (using appropriate cuff size), and oxygen saturation
Examine skin for color, temperature, turgor, and capillary refill time
Auscultate heart and lungs
Palpate pulses
Assess abdomen and extremities.
Investigations:
Complete blood count (CBC) with differential
Blood cultures (essential in suspected sepsis)
Electrolytes, BUN, creatinine
Glucose
Lactate (marker of tissue hypoperfusion)
Arterial blood gas (ABG) or venous blood gas
Chest X-ray (if respiratory symptoms)
Echocardiogram (to assess cardiac function and rule out cardiogenic shock)
ECG
Coagulation profile (PT/INR, aPTT)
Cardiac enzymes if myocarditis is suspected.
Differential Diagnosis:
Other causes of poor perfusion such as severe anemia, opioid overdose, neurogenic shock, adrenal insufficiency, and hypoglycemia
Differentiating between types of shock is crucial for targeted management.
Management
Initial Management:
ABC (Airway, Breathing, Circulation) approach
Secure airway if compromised
Provide supplemental oxygen
Establish intravenous access (two large-bore cannulas)
Begin rapid fluid resuscitation with isotonic crystalloids (e.g., Normal Saline or Ringer's Lactate) at 20 mL/kg over 5-10 minutes, repeated up to 60 mL/kg as needed while monitoring response
Monitor vital signs and perfusion continuously.
Medical Management:
Vasoactive agent selection is guided by the type of shock and response to fluid resuscitation
\n\nFor cold shock/hypoperfusion unresponsive to fluids:
\n- Dopamine: First-line agent in many protocols
Dose: 2-20 mcg/kg/min IV infusion
Provides inotropic and chronotropic effects, and at higher doses, some vasopressor effect
\n- Norepinephrine: If dopamine is ineffective or vasodilation is predominant
Dose: 0.05-1 mcg/kg/min IV infusion (titrate to BP)
Potent alpha-agonist with some beta-1 agonism
\n- Epinephrine: Can be used if other agents are insufficient or in severe cases
Dose: 0.05-0.3 mcg/kg/min IV infusion (titrate to BP)
Potent alpha and beta agonist
\n\nFor warm shock/vasodilation (septic shock):
\n- Norepinephrine: Generally considered first-line
Dose: 0.05-1 mcg/kg/min IV infusion
\n- Epinephrine: Can be used as an alternative or adjunct
Dose: 0.05-0.3 mcg/kg/min IV infusion
\n\nFor cardiogenic shock:
\n- Dobutamine: Primarily inotropic support
Dose: 2-20 mcg/kg/min IV infusion
\n- Epinephrine: Can be used for combined inotropic and vasopressor support
Dose: 0.05-0.3 mcg/kg/min IV infusion
\n\nImportant Considerations:
\n- Always start with a continuous infusion and titrate to achieve target mean arterial pressure (MAP) or adequate perfusion
\n- Dilution: Dopamine, Norepinephrine, Epinephrine, Dobutamine are typically diluted to a concentration of 1000 mcg/mL or 4000 mcg/mL for pediatric use
Always verify local protocols
\n- Continuous monitoring of vital signs, lactate, and urine output is essential.
Surgical Management:
Rarely indicated for initial shock management, but may be required for definitive treatment of underlying causes like surgical bleeding, bowel obstruction, or appendicitis.
Supportive Care:
Monitor urine output hourly
Maintain adequate glycemic control
Consider mechanical ventilation if respiratory failure
Use broad-spectrum antibiotics as soon as sepsis is suspected (within 1 hour)
Provide nutritional support
Monitor temperature closely
Manage pain and sedation as needed
DVT prophylaxis if prolonged immobility.
Complications
Early Complications:
Acute kidney injury
Acute respiratory distress syndrome (ARDS)
Myocardial dysfunction
Disseminated intravascular coagulation (DIC)
Multi-organ dysfunction syndrome (MODS)
Hypoglycemia
Hypothermia or hyperthermia.
Late Complications:
Post-intensive care syndrome (PICS)
Neurodevelopmental deficits
Chronic kidney disease
Growth failure
Psychological sequelae.
Prevention Strategies:
Prompt and aggressive fluid resuscitation
Early recognition and treatment of sepsis
Judicious use of antibiotics
Adequate oxygenation and ventilation
Close hemodynamic monitoring
Management of underlying etiologies.
Prognosis
Factors Affecting Prognosis:
Severity of shock, etiology of shock, age of the child, presence of comorbidities, time to initiation of effective treatment, and response to therapy
Higher initial lactate levels and prolonged hypotension are poor prognostic indicators.
Outcomes:
Survival rates vary significantly
Children with hypovolemic shock generally have a good prognosis with timely fluid resuscitation
Sepsis and cardiogenic shock have higher mortality rates
Survivors may experience long-term sequelae.
Follow Up:
Children who have experienced shock, especially septic or cardiogenic shock, require close follow-up
This includes monitoring for growth and development, cardiac function, renal function, and neurocognitive outcomes
Rehabilitation and psychological support may be necessary.
Key Points
Exam Focus:
Differentiate between cold and warm shock based on peripheral perfusion
Understand the stepwise approach to fluid resuscitation and then vasoactive agent selection
Know common pediatric vasoactive agents (dopamine, norepinephrine, epinephrine, dobutamine) and their typical starting doses and indications
Recognition of hypotension in children is age-dependent.
Clinical Pearls:
Always look for signs of poor perfusion BEFORE hypotension
Capillary refill time is a sensitive indicator
A narrow pulse pressure can suggest cardiogenic shock
Continuous infusion of vasoactive agents is crucial and requires close monitoring and titration
Early broad-spectrum antibiotics are life-saving in suspected sepsis.
Common Mistakes:
Delaying fluid resuscitation while awaiting IV access
Using vasopressors without adequate fluid resuscitation
Inappropriate selection of vasoactive agents
Not recognizing or treating underlying causes of shock
Inadequate monitoring of response to treatment
Incorrect calculation or administration of vasoactive drug doses.