What is Shock ? ? ?

Shock is a failure of the circulatory system to maintain adequate perfusion of vital organs.

cellular hypoxia

anaerobic cellular metabolism

accumulation of waste products in cells

cellular death

Types of Shock

• Distributive Shock– Neurogenic shock– Septic shock– Anaphylactic shock

• Hypovolemic Shock• Cardiogenic Shock

Distributive Shock

Distributive shock occurs as a result of inadequate vascular tone.

• neurogenic shock• septic shock• anaphylactic shock

Hypovolemic Shock

Hypovolemic shock occurs when there is a large reduction in the circulating blood volume.

• Actual hypovolemic shock - loss of blood or fluid

• Relative hypovolemic shock - internal fluid shifts from intravascular to interstitial space.

Cardiogenic Shock

Cardiogenic shock occurs when the heart is unable to function adequately resulting in insufficient blood flow to tissue and organs.

• myocardial infarction

• obstruction of blood flow

• congestive heart failure

Stages of Shock

• Initial Stage

• Compensatory Stage

• Progressive Stage

• Irreversible Stage

Stages of Shock

• Initial StageInitial Stage

• Compensatory Stage

• Progressive Stage

• Irreversible Stage

Initial Stage

• Initially, the body compensates with the onset of shock.

• No changes are noted clinically.

• Changes are beginning to occur on the cellular level.

Stages of Shock

• Initial Stage

• Compensatory StageCompensatory Stage

• Progressive Stage

• Irreversible Stage

Compensatory Stage

• Fluid shift from insterstital to intravascular space.

• Activation of SNS - activation of epinephrine and norepinephrine.

• Kidneys release renin into blood formation of angiotension & release of aldosterone, ADH

Decreased CO

SNS stimulation

Epinephrine & norepinephrine released

Vasoconstriction

Increased SVR

Renin secreted by kidney

Angiotension

Aldosterone

ADH

Increase blood volume

hydrostatic pressure

fluid pulled into capillary

Blood Pressure Maintained

• Initial Stage

• Compensatory StageCompensatory Stage

• Progressive StageProgressive Stage

• Irreversible Stage

Stages of Shock

Progressive Stage

• Vicious circle of compensation eventually leads to decompensation.

• Blood pressure starts to fall - SBP below 80 is considered danger signal.

• Tachycardia; tachypnea; decreased urine output; decreased body temperature; cold, pale clammy skin.

• Initial Stage

• Compensatory StageCompensatory Stage

• Progressive StageProgressive Stage

• Irreversible StageIrreversible Stage

Stages of Shock

Irreversible Stage

• Body attempts at compensation have failed - death is imminent.

• Pooling and sludging of blood; thrombosis of small vessels occurs.

• Tissue hypoxia and anoxia occur - lactic acid accumulation contributes to cell death.

Management of Shock

* Treat underlying cause.– Knowing the cause of the shock is necessary to

treat the shock.

Management of Shock

* Oxygenation– In all types of shock, supplemental oxygen is

administered to protect against hypoxemia.

Management of Shock

* Positioning– the recommended position for the patient in

shock is supine with legs elevated 45 degrees.

Management of Shock

* Replacing Fluid Volume– The primary goal of shock therapy is to

increase the circulating blood volume.• crystalloids

• colloids

– Fluid replacement should be based on central venous pressures or pulmonary artery pressures and cardiac output.

Management of Shock

– Vasoconstrictors• Dopamine

• Norepinephrine

– Vasodilators• Nitroprusside

• Nitroglycerin

– Sympathomimetics• Epinephrine

– Corticosteriods• Decadron

• Solumedrol

– Appropriate antidotes or antibiotics

* Pharmacologic Agents

Complications of Shock

• Metabolic Acidosis

• Acute Tubular Necrosis

• DIC

• ARDS

• SIRS & MOSF

SIRS & Multi-Organ System Failure

• May occur in patient who has survived a shock episode.

• Commonly associated with septic shock, especially gram negative septic shock

Systemic Inflammatory Response Syndrome

Causes damage to organs and tissues by:– damaging vascular endothelial cells– hypermetabolism– maldistribution of blood flow to organs– organ hypoperfusion

New Priorities in Septic Shock Care

• Multiple multi national research projects

• 4 new findings, care priorities1. Use of activated protein C (Xigris)- new IV

medication for septic shock• expensive but effective

2. Use of high dose steroids • test for reactiveness, then individualized dosing

3. Intensive insulin therapy• tight glucose control (<110)

4. Aggressive fluid therapy, monitoring

Shock: Recap

Types of Shock

• Distributive Shock– Neurogenic shock– Septic shock– Anaphylactic shock

• Hypovolemic Shock

• Cardiogenic Shock

Recap

Stages of Shock

• Initial Stage

• Compensatory Stage

• Progressive Stage

• Irreversible Stage

Recap…..

Treatment of Shock– O2,O2,O2, did I say oxygen?– Positioning– Fluids

• Colloids• Crystalloids

– Pharmacological agents

Cutting Edge Therapies

• Use of Xigris

• Use of steroids

• Intensive insulin therapy

• Aggressive fluid resuscitation/ monitoring