Lec 30 Shock Flashcards by Anna Cushing

What is definition of shock?

inadequate organ perfusion to meet tissue’s oxygenation demand

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What is the definition of hypotension?

transient fall in BP

systolic BP < 90 OR mean arterial P < 60 OR decrease in systolic BP > 40 mmHg from pts baseline

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What is pathophysiology of shock?

ATP + H2O –> ADP + Pi + H

lack of ATP production –> Na/K failure
anaerobic metabolism –> accumulation of acid –> metabolic acidosis
cell swelling leading to rupture + death

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Why do we monitor pt undergoing shock?

to understand their disease
to describe pts physiologic status
facilitate diagnosis and treatment of shock

b/c shock cna change rapidly

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When do you use pulm artery catheter with shock?

to get index of volume status [normal central venous pressure = normal volume] and cardiac status [calculate CO/CI]

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How can you use ultrasound to measure volume status?

if SVC not collapsed means there is sufficient volume status

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Why might you not do swan gans catheter on ever pt who comes in with shock?

can cause trauma/complications

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What does SVI tell you?

stroke volume index = stroke volume / body mass

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What does LV stroke work index tell you?

measure of cardiac contractility

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What is equation for systemic vascular resistance index?

SVRI = [MAP- CVP] / CI * 80

increases with vasoconstriction, decreases with vasodilation

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What is equation for pulmonary vascular resistance index?

PVRI = [MPAP - PWAP] / CI * 80

increases with constriction, PE, hypoxia

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Lung circuit resistance affects which part of heart function? what about systemic circuit resistance?

pulm circuit resistance affects RV function

systemic circuit resistance affects LV function

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What is equation for vascular resistance?

vascular resistance = change in pressure / blood flow

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What is definition of O2 delivery?

volume of gaseous O2 delivered to LV per min

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What is the definition of O2 consumption?

volume of gaseous O2 which is actually used by the tissue per min

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What is definition of O2 demand?

volume of O2 actually needed by tissues to function in an aerobic manner

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What happens if O2 demand > consumption?

anaerobic metabolism

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What are 3 signs of organ hypo-perfusion?

mental status changes = obtunded b/c lack of perfusion to brain
oliguria = lack of kidney perfusion
lactic acidosis

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What are the 4 categories of shock?

hypovolemic
cardiogenic
distributive
obstructive

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What are the goals of shock resuscitation?

restore BP
normalize systemic perfusion
preserve organ function

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What are some causes of hypovolemic shock?

hemorrhage
vomiting
diarrhea
dehydration
burns

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What is hypovolemic shock? What happens to CO/SVR/venous return/PAWP?

step1

shock related to loss of fluid

signs:
- decrease CO, decrease venous return, increase SVR

decrease PAWP [indicates reduced diastolic filling pressure]

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What is the first sign of shock?

step1

tachycardia

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What usually causes shock in setting of disseminated intravascular coagulation secondary to trauma?

step1

Study These Flashcards

usually due to sepsis

What is treatment for hypovolemic shock?

main treatment = give fluid might need to use pressors transiently

When do give crystalloids vs colloids vs fresh frozen plasma in hypovolemic shock treatment?

``` crystalloids = cheaper colloids = give if mostly blood loss but have no actual survival benefit over crystalloids ``` give blood to supplement either give fresh frozen plasma [FFP] if underlying bleeding disorder caused the loss

What do you need to watch out for when you infuse pt with large volumes NaCl?

watch for hyperchloremic metabolic acidosis

What is cardiogenic shock? signs [CO, SVR, PAWP, venous return, left ventricular stroke work]? step1

cardiogenic shock is shock due to defect in cardiac function heart failing --> can't pump --> elevated filling pressure signs: - decrease CO - increase SVR - increase PAWP - decrease venous return - decrease left ventricular stroke work = less contractility of heart

What is PAWP a stand-in for when we are talking about shock? step1

PAWP = LA pressure = diastolic filling pressure increases when heart is failing decreases when less volume to fill up

What is equation for coronary perfusion pressure? step1

coronary PP = DBP - PAWP = diastolic BP - filling pressure

What is goal for coronary perfusion pressure needed to maintain?

coronary PP > 50 mmHg

What treatment for cardiogenic shock?

- goal is to improve myocardial function - fluids first then cautious pressors remember aortic diastolic BP pressure drives coronary perfusion if inotropes and vasopressors fail --> do intra-aortic balloon pump = increases diastolic BP so increased gradient

What are the 4 types of distributive shock? step1

- sepsis - anaphylactic - acute adrenal insufficiency - neurogenic

What happens to CO/SVR/venous return/PCWP in distributive shock?

- variable CO [increase according to 1st aid] - variable PAOP [decrease according to 1st aid] - decrease SVR - increased venous return

In what types of shock can you restore BP with IV fluids? step1

- in hypovolemic/cardiogenic shock | - not in distributive [septic/neurogenic/anaphylactic] shock

What type of shock does pt appear cold, clammy b/c of vasoconstriction?

hypovolemic/cardiogenic

What type of shock does pt appear warm, dry because of vasodilation?

distributive shock [septic, neurogenic, anaphylactic]

What happens to body in distributive shock?

systemic inflammatory response syndrome

How do you treat pt with distributive shock?

- volume replacement - early antibiotic administration if sepsis - steroid if bee sting - inotrope [dopamine] - if low MAP < 60 --> give dopamine and norepinephrine

How do you treat sepsis?

- give fluids - correct the cause: antibiotics, debridement - vasopressors: phenylephrine, norepinephrine

What causes adrenal crisis distributive shock?

- autoimmune adrenalitis or adrenal apoplexy [hemorrhage or infarct of adrenal]

How do treat ddrenal crisis distributive shock?

give steroids and take care of adrenal crisis

What are some causes of obstructive shock?

- cardiac tamponade - tension pneumothorax - massive PE

What are signs of obstructive shock [to CO, PAWP, SVR]?

- decrease CO - increase PAWP - increase SVR looks like cardiogenic shock

What happens to PAWP, CO, SVR in hypovolemic shock?

- decrease PAWP - decrease CO - increase SVR

What happens to PAWP, CO, SVR in cardiogenic shock?

- increase PAWP - decrease CO - increase SVR

What happens to PAWP, CO, SVR in distributive shock?

- decrease PAWP or no change - CO variable - decrease SVR

What happens to PAWP, CO, SVR in obstructive shock?

- increase PAWP - decrease CO - increase SVR

Why use vasopressors in shock? Possible complications? Who should you avoid using it in?

- to increase contractility - but need preload first so only give pressor after you give fluids - risk tachycardia and increase myocardial O2 consumption if used too soon - don't use in post-MI shock pt

What types of vasopressors could you use in shock?

dopamine dobutamine norepinephrine epinephrine

What is effect of dopamine low dose? moderate/ high? side effects?

low dose = acts on dopaminergic receptors moderate dose = B effects --> contractility high dose = a-effects --> vasoconstriction

What is effect of dobutamine? when should you caution use?

selective B agonist potent inotrope = increase contractiliy + stroke work caution in hypotension [may preciptate tachycardia or worsen hypotension]

What is action of norepinephrine?

- mostly a agonist = vasopressor - also some B agonist = inotrope, chronotrope large doses may cause lactic acidosis

What is action of epinephrine?

- a and B adrenergic effects - potent inotrope and chronotrope - increases myocardial oxygen consumption particularly in coronary heart disease

What is treatment of choice for distributive shock?

epinephrine = epi pen

What is action of amrinone?

phosphodiesterase inhibitor positive inotrope + vasodilation increases CO without an increase in cardiac stroke work second line after dobutamine

24 year old male victim of a shotgun blast to his right lower quadrant/groin at close range. Hemodynamically unstable in the field and his right lower extremity was cool and pulseless upon arrival to the trauma resuscitation area. Patient received 12 L crystalloid, 15 units of blood, 6 units of FFP, and 2 6 packs of platelets. HR 130, BP 96/48, T 34.7° C PAWP 4, CVP 2, CI 2.2, SVRI 2700, Diagnosis? Treatment?

LOW PAWP/CVP/CI + HIGH SVR == hypovolemic shock give volume/fluids

68 year old female restrained driver who was involved in a high speed MVC. She sustained a pulmonary contusion and fractured pelvis. Intubated and monitored with PA-C PCWP = 22, CI = 2.5, SVRI = 2800, HR = 120, BP = 110/56, SpO2 = 91, urine output is reduced What do you think...

high SVR and HR, normal BP, low urine output, high PAWP think cardiogenic or obstructive next step = do echo and figure out whats going on with the heart

Lec 30 Shock Flashcards

(58 cards)