1. SHOCK

2. SHOCK
Shock is a critical condition that results from inadequate tissue delivery of O2 and nutrients to meet tissue metabolic demand. Shock does not depend upon blood pressure, shock can occur with a normal, increased or decreased systolic blood pressure. In children most shock characterized by low cardiac output ; however in shock caused by sepsis or anaphylaxis , CO may be high. All types of shock result in impairment of vital organs such as Brain and Kidney.

3. Shock can result from
Inadequate blood volume or oxygen carrying capacity (Hypovolemic Shock, including hemorrhagic shock)
Inappropriate distribution of blood volume and flow (Distributive shock)
Impaired cardiac contractility (Cardiogenic shock)
Obstructed blood flow (Obstructive shock)

4. Hypotension Formula
In Children 1 to 10 years of age, hypotension is present if the systolic blood pressure reading is less than
70mmHg + (child’s age in years × 2) mm Hg

5. Factor influencing O2 delivery
Volume of blood present in the ventricle before contraction
Preload
Stroke Volume ×
Heart Rate
Cardiac Output ×
O2 Content
O2 Delivery
Strength of
Contraction
Contractility
Resistance against which the ventricle is ejecting
Afterload

6. Common Signs of Shock resulting from Cardiovascular Compensatory Mechanisms

7. Shock progression is Unpredictable
This progression is typically an accelerating Process
SHOCK
Possibly hours
COMPENSATED SHOCK
HYPOTENSIVE SHOCK
Potentially minutes
CARDIAC ARREST

8. Shock can be categorized into 4 basic types
Hypovolemic
Distributive
Septic Shock
Anaphylactic Shock
Neurogenic Shock
Cardiogenic
Obstructive

9. Hypovolemic Shock Most common cause of shock in children
Typically represents depletion of both intravascular and extravascular fluid volume. As a result , adequate fluid resuscitation often require administration of fluid boluses that exceed the volume of the estimated intravascular deficit.
Volume loss can result from
Diarrhea
Vomiting
Hemorrhage(Internal and External)
Inadequate fluid intake
Osmotic diuresis(DKA)
Third space losses( Fluid leak in to tissues)
Large Burns

10. Hypovolemic Shock is characterized by decreased preload leading to reduced stroke volume and low cardiac output.
Tachycardia, Increased SVR and Increased cardiac contractility are the main compensatory mechanisms.

11. Distributive Shock
It is characterized by inappropriate distribution of blood volume with inadequate organ and tissue perfusion(especially the splanchnic vascular bed)
Most common forms are
Septic Shock
Anaphylactic Shock
Neurogenic Shock( Ex: Head Injury, Spinal Injury)

12. Findings consistent with Distributive Shock

13. Septic Shock
Most common form of Distributive shock. It is caused by infectious organisms or their by products(endotoxin) that stimulate the immune system and trigger the release of inflammatory mediators.
Typically evolves from a systemic inflammatory response in early stages to septic shock in the late stages, may evolve over days or just a few hours.
In the early stages , signs are often subtle and may be difficult to recognize because peripheral perfusion may appear to be good. Child may have fever or hypothermia and WBC may be decreased, normal or Increased.

14. Anaphylactic Shock
Anaphylactic shock is an acute multisystem allergic response caused by a severe reaction to a drug, vaccine, food, toxin, plant, venom or other antigen. It can occur within seconds to minutes
The reaction is characterized by vasodilatation, arterial vasodilation, increased capillary permeability and pulmonary vasoconstriction.
Signs may include Anxiety or agitation, Nausea and vomiting, Urticaria, Angioedema(swelling of face,lips and tongue), Respiratory distress with stridor or wheezing, Hypotension, Tachycardia.

15. Neurogenic Shock
Also known as spinal shock, results from a cervical or upper thoracic(above T6) injury that disrupts the sympathetic nervous system of blood vessels and the heart.
Sudden loss of the sympathetic nervous system signals to the smooth muscle in the vessel results in uncontrolled vasodilation.
Primary signs are
Hypotension with a wide pulse pressure
Normal heart rate or Bradycardia Other signs include increased RR, Diaphragmatic breathing, motor or sensory deficits.

16. Cardiogenic Shock
Cardiogenic shock results from inadequate tissue perfusion secondary to myocardial dysfunction.
Common causes include CHD, Myocarditis, Cardiomyopathy, Arrhythmias, Sepsis, Poisoning or drug toxicity, Myocardial Injury(ex: trauma)
Cardiogenic shock is characterized by marked tachycardia, high SVR, and decreased cardiac output.

17. Findings consistent with Cardiogenic Shock

18. Obstructive Shock
In obstructive shock, cardiac output is impaired by a physical obstruction of blood flow.
Causes include
Cardiac Tamponade
Tension Pneumothorax
Duct-dependent congenital heart lesions
Massive pulmonary embolism
The physical obstruction to blood flow results in low cardiac output, inadequate tissue perfusion and a compensatory increase in SVR.

19. Cardiac Tamponade

20. Tension Pneumothorax

21. Duct-dependent congenital heart lesions Findings of left ventricular outflow obstructive lesions

22. Pulmonary Embolism

26. Septic shock algorithm