shock Flashcards
what is shock
alteration in tissue perfusion
Complex syndrome of inadequate blood flow.
(decreased perfusion)
Hemodynamic & metabolic problem leading to decreased O2 to the cells and tissues resulting in organ failure.
In other words: The body can no longer meet the cellular oxygen demands
diagnosis of shock
MAP < 60 or evidence of organ hypoperfusion
Global indicators:
Serum lactate (lactic acid)
Arterial base deficit
Serum bicarbonate
Venous oxygen saturation
stages of shock
Initial/Compensatory/Nonprogressive
Progressive
Refractory/Irreversible
initial stage
Decreased cardiac output (CO)
Decreased tissue perfusion
The body quickly moves into the Compensatory Stage
whats happening in the compensatory stage
Body attempts to maintain CO, BP & tissue perfusion
Sympathetic nervous system (SNS) kicks in to correct the problem
- Neural response
- Hormonal response
- Chemical response
compensatory stage
neural response
Increased HR & contractility
Arterial & venous vasoconstriction
Shunting of blood to vital organs
compensatory stage
hormonal response
Activation of Renin response
Stimulation of anterior pituitary
Stimulation of adrenal medulla
compensatory stage
chemical response
Related to sympathetic redistribution of blood to priority organs
Chemoreceptors sense decreased O2 and increased CO2
Leads to increased rate and depth of respirations
whats happening in the progressive stage
Compensatory mechanisms fail
Shock cycle is perpetuated
Systemic Inflammatory Response Syndrome (SIRS)
Cells switch to anaerobic metabolism (produces large amounts of lactic acid)
Every body system is effected
progressive stage
vascular effects
Increased vascular permeability
Intravascular hypovolemia
Tissue edema
Further decline in tissue perfusion
progressive stage
cellular effects
Apoptosis
Na+/K+ pump fails—cells swell
Mitochondria swell & rupture
Cell now unable to use O2 even if it were to receive it
progressive stage
cardiac effects
Ventricular failure from release of myocardial depressant cytokines (MDF)
Microvascular thrombosis
Lactic acidosis
progressive stage
pulmonary effects
Acute respiratory failure
↑ Capillary membrane permeability
Acute lung injury (ALI)
Acute respiratory distress syndrome (ARDS
progressive stage
neurologic effects
Microvascular thrombosis ->
Cerebral hypoperfusion ->
SNS dysfunction ->
- Cardiac & respiratory depression
- Thermoregulatory failure
- Coma
progressive stage
GI effects
Necrotic bowel, liver & pancreas
GI tract failure
Hepatic failure
Pancreatic failure
