Shock - SALA/NERIA

what is shock? describe it

state of hypoperfusion

hypoperfusion = inadequate supply of oxygen to tissue —> tissue death

what is perfusion

the delivery of nutrients and oxygen rich blood to tissue

what does adequate perfusion require

oxygen exchange in the lungs, nutrients in the form of glucose in the blood, waste removal, primarily through the lungs

what is the perfusion triangle

pump = heart

fluid = blood

pipes = blood vessels

what is the role of blood volume

sustainable blood volume = carries and delivers O2 to organs and tissue

not enough blood = no delivery = no adequate supply to body with O2

what is the role of the heart?

circulates blood around body, damage/malfunction = inadequate perfusion = tissue death

What is the role of blood vessels?

transportation and delivery of O2-rich blood to organs and tissue

sudden dilation of blood vessels = render NORMAL amt of blood = inadequate

INCREASED PERMEABILITY can cause fluid shift OUTSIDE blood vessels

what are your four types of shock?

Obstructive, Cardiogenic, Hypovolemic, Distributive, Neurogenic, Anaphylactic, Septic

what is obstructive shock

caused by physical obstruction in the flow of blood

what are the reasons for obstructive shock

decreased preload - heart is unable to refill and stretch fully, resulting in successful contraction

increased afterload - increased resistance that the heart must overcome to pump blood

3 causes of decreased preload in obstructive shock

1. cardiac tamponade

2. tension pneumothorax

3. right ventricle + pulmonary embolism that obstructs the left ventricle

what is cardiac tamponade

blood accumulation in between pericardium sac and myocardium, puts pressure on the heart, prevents full refill of ventricles

What is tension pneumothorax

escaped air in thorax puts pressure on great vessels and heart, prevents full refill of ventricles

what is right ventricle + pulmonary embolism that obstructs the left ventricle

a blood clot in the pulmonary artery that prevents the right ventricle from pumping blood —> increasing RV preload —> increasing size of RV —> pushing on the left ventricle —> decreased LV preload, b/c LV pumps blood into system, and theres a decreased preload, that means decreased STROKE volume = shock

what are 3 increased afterload causes of obstructive shock

aortic dissection, aortic stenosis, pulmonary embolism

what is aortic dissection, how does it happen, and how it causes obstructive shock

aortic dissection = tear in aorta

weakened inner aortic wall due to chronic stress/disease

a tear in inner lining

the high pressure blood forces its way through the tear and rushes between inner + middle layer —> “dissecting them”

false lumen forms —> false lumen can bulge + block blood flow to tissue ORRRRR can rupture into pericardial sac = cardiac tamponade

what is aortic stenosis, how does it happen, and how does it cause obstructive shock

age-related calcium buildup (calcification) —> Stiffens the valve leaflets = high resistance obstruction

what is pulmonary embolism that increases afterload?

blood clot in pulmonary artery that obstructs the right ventricle, the right ventricle needs to pump harder to pump blood through = increased afterload, and since the RV is backed up, theres an increase in RV preload = thinner/stretchy = RV swelling

what is cardiogenic shock?

caused by damage or malfunction of the heart

what is cardiogenic shock caused by?

myocardial failure, arrythmias, valve failures

explain how myocardial failure can lead to cardiogenic shock

damage to myocardium due to MI = LV is unable to contract + pump blood out to systemic circuit

heart failure = heart can’t pump adequately

explain how arrythmias can cause cardiogenic shock

tachyarrythmias - heart if beating way too fast, resulting in the ventricles not having enough time to fill up —> decreased stroke volume = decreased CO

bardyarrythmias- heart is beating way too slow, resulting in decreased CO b/c CO=HR*SV

how does valve failure lead to cardiogenic shock?

valve prevents backflow, if a valve isn’t working properly, it could result in the backup of blood to previous chamber.

Stenosis = narrowing (from stiffening) of valve

Regurgitation = leak/backflow

causes of valve failure

age related, calcification, congenital defects, infection, hypertension

what is hypovolemic shock

caused by extreme blood/fluid loss

what are the 3 fluids you can lose to go into hypovolemic shock

blood, plasma, body fluids

extreme blood loss:

traumatic hemorrhagic = exsanguinating hemorrhage (laceration)

non-traumatic hemorrhagic. = med emergency causing internal bleeding (GI bleed, aortic aneurysm, ruptured varicose veins)

extreme body fluid loss:

GI losses: vomiting diarrhea

Renal losses: pee (Diabetics at risk b/c sugar in blood = decreased water absorption = more pee)

sweating: fever, heat stroke

plasma loss

plasma loss from thermal burns —> leaky capillary syndrome

what is distributive shock?

widespread vasodilation

Describe neurogenic shock

an injury above the T6 vertebrae, causes the body to cut off SNS pathway, so only the PSNS is in control (decreased HR, vasodilation, decreased BP)

dilated blood vessels, same stroke volume = less blood to vital organs = hypoperfusion = shock

Describe anaphylactic shock

allergen exposure = mast cell + WBC recruitment

widespread allergic reaction + immune response ^^

immune cells release histamine —> dilates blood vessels + increases permeability of blood vessels

^^ both cause hypoperfusion + fluid shift

Describe septic shock

when an infection enter the bloodstream —> widespread systemic immune response = WBC recruitment—> dilate blood vessels + permeability

causes hypoperfusion + fluid shift outside

as water shifts outside vessels, O2 can’t rlly travel through water well, O2 cant get to vital organs to perfuse

stages for shock: compensated

pulse, RR, BP, mental status, skin, pupils

increase; increase; normal; alert, anxious; warm, pink, sweaty; PERRL

stages for shock: decompensated

pulse, RR, BP, mental status, skin, pupils

increase; increase; decrease; verbal, painfully responsive; cool, pale, diaphoretic; sluggish

stages for shock: irreversible

pulse, RR, BP, mental status, skin, pupils

decrease; decrease; decrease; unresponsive; ashen, gray, cold; non-reactive

difference between children and adult shock

INFANTS AND CHILDREN CRASH AND BURN

adults reach the decompensated stage faster, but stay in it longer

children compensate for longer, then deteriorate VERY quickly

treatments for shock

position (supine), high concetration O2, ALS, rapid transport, thermoregulation