Shock Flashcards
What is shock?
- Circulatory system is unable to provide adequate circulation and tissue perfusion
- leads to failure to deliver O2 to vital organs
3.cellular hypoxia occurs + energy deficit
Why is oxygen important in cells
Cells require O2 to produce energy and maintain life
What does decreased tissue perfusion lead to?
1.Hemorrhage
2.Hypovelmia
3.Cardiac failure
4.Neurological injury
What is Hypovolemic shock?
Circulatory failure due to volume loss (blood/fluids)
caused by hemorrhage, dehydration or plasma loss (burns, trauma)
What is Cardiogenic Shock
Shock that occurs when the heart is unable to pump enough blood to meet the bodies demands
caused by heart problems: MI, heart failure, dysrhythmias, etc
What is obstructive shock?
Shock caused by a condition that prevents oxygen from getting to organs/tissue
caused by clots, collapsed lungs, aortic dissection, cardiac compression (pericarditis/ tamponade)
What are the 4 Disruptive shocks?
Septic
Anaphylactic
Neurogenic
Psychogenic
What is septic shock?
Shock caused by an infection dropping blood pressure to a dangerous level
What is Anaphylactic shock?
Also known as Anaphylaxis, is shock caused by a severe reaction to an allergen, leading to a drop in BP, airway tightening
What is neurogenic shock?
Shock caused by injury to the spinal cord.
manifests with hypotension, bradyarrhythmia’s, temperature dysregulation and vasodilation.
What is psychogenic shock?
Shock caused by stress, pain or fright.
HR drops and vessels dilate leading to hypo perfusion in the brain and eventually loss of consciousness.
What is compensatory shock (stage 1)?
Acute blood loss of 10 - 15 % of normal blood volume
Activation of sympathetic nervous system - can be reversed through the bodies compensatory mechanism
Signs and symptoms of compensatory shock (stage 1)?
BP maintains
BP declines when patient stands up
Increase in HR
Paleness
Anxiety
What is progressive shock (stage 2)?
Acute blood loss of 20 - 40%of normal blood volume
Massive activation of parasympathetic nervous systems - compensatory mechanisms kick in
Signs and symptoms of progressive shock (stage 2)?
Systolic BP drops 10-20
Tachycardia
Skin pale and cool
Decreasing LOA
Thirst
Decreased urine output
Angina may occur
What is irreversible shock (stage 3)?
Acute loss of >40% of normal blood volume
Leads to irreversible tissue damage to the heart, brain and kidneys - can lead to death
Signs and symptoms of irreversible shock (stage 3)?
Unconsciousness
severe hypotension
decreasing heart rate
What is neurogenic compensation?
Fight or flight response (sympathetic nervous system)
-Vasoconstriction
-Increased HR
-Preferential perfusion to brain and heart
What is chemical compensation?
When does it occur?
Occurs after 30 minutes
Decreased cardiac output + Increased O2 tissue perfusion = decreased PaO2. This activates chemoreceptors to stimulate the respiratory system into respiratory alkalosis .
This can lead to cerebral ischemia, cerebral vessel constriction and decreasing LOA
What is hormonal compensation?
Can occur when impulses from the sympathetic nervous system occur:
- adrenal medulla releases epi / norepi (potent vasoconstrictors)
- decreased blood flow to kidneys activates the Renin-Angiotensin system
- hypothalamus stimulates posterior pituitary gland, leading to release of hormones that influence metabolism of macronutrients.
What two processes are aimed to be restored when initiating shock therapy?
Cellular perfusion
Oxygenation
