Shock States Flashcards
central venous pressure
A measure of the pressure exerted by fluid in the right atrium
Indicative of right-sided heart failure
normal CVP
0-6 mm Hg
Elevated CVP
conditions that cause an increase in the amount of fluid in the right atrium (e.g. fluid overload, cardiogenic shock)
Decreased CVP
conditions that cause a decrease in the amount of fluid in the right atrium (e.g. dehydration, distributive shock)
mean arterial pressure
indicates the average driving force in the arterial system throughout the cardiac cycle
When available, MAP should be used in hemodynamic assessment and decision making
How to calculate MAP
MAP = [SBP + 2(DBP)]/3
Pulmonary arterial pressure (PAP)
a measure of the systolic and diastolic pressures in the pulmonary artery (15-25/5-15)
elevated PAP
caused by conditions that increase the amount of fluid in the pulmonary artery or conditions that decrease the elasticity of the pulmonary artery (e.g. hypervolemia, pulmonary hypertension)
decreased PAP
conditions that cause a decrease in the amount of fluid in the pulmonary artery (e.g. hypovolemia)
pulmonary capillary wedge pressure (PCWP) or Pulmonary Artery Occlusion Pressure (PAOP)
measure of the pressure in the left ventricle at end-diastole (maximal stretch)
indicative of left-sided heart function
Reflection of the tendency to develop pulmonary edema
Should be kept at the lowest point at which cardiac performance is acceptable to optimize cardiac performance and minimize tendency for pulmonary edema
normal PCWP
6-12 mm Hg
increased PCWP
conditions that increase the pressure in the left ventricle at end-diastole (e.g. increased fluid, decreased elasticity of the ventricle)
decreased PCWP
conditions that decrease the pressure in the left ventricle at end-diastole (e.g. hypovolemia)
cardiac output
amount of fluid in liters per minute that the heart pumps into systemic circulation
How to calculate cardiac output
CO = HR x SV
normal cardiac output
4-8 L/min
increased CO
increased by factors that increase the heart rate or increase the amount of blood that the heart puts out with each beat (e.g. inotropic agents, excess fluid)
decreased CO
decreased by factors that decrease heart rate or decrease the amount of blood that the heart puts out with each beat (e.g. drugs that decrease contractility, hypovolemia)
cardiac index (CI)
CO/body surface area
More accurate than cardiac output because it takes body surface area into account
normal cardiac index
2.5-4 L/min
stroke volume
volume of blood pumped out of the left ventricle during each systolic contraction
systemic vascular resistance (SVR)
the resistance provided by the systemic circulation against which the left ventricle must pump blood
How to calculate SVR
SVR = (MAP - mean CVP x 80) / CO
normal SVR
800-1200 dynes/sec/cm-5
mixed venous o2 saturation (SVO2)
continuous display of mixed venous oxygen saturation by the pulmonary artery catheter
Assesses the effectiveness of peripheral oxygen delivery
normal SVO2
60-80%
low SVO2
implies increased tissue extraction of O2
The patient has tapped the venous reserve of O2
Needs more O2
Causes:
-decreased O2 supply (e.g. decreased CO, decreased FiO2, anemia)
-increased O2 demand (e.g. fever, shivering, increased WOB)
high SVO2
implies decreased tissue extraction of O2
high return of O2 is often a most early indicator of patient status change
Not using O2 (worse than too low)
Causes
-increased O2 supply (e.g. FiO2 > need)
-decreased O2 demand (e.g. hypothermia)
-decreased effective O2 delivery and uptake by the cells (e.g. sepsis, shift of oxyhemoglobin cures to the left)
hypovolemic shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: low
CVP: low
PCWP: low
SVR: high
SVO2: low
hypovolemic –> less pressure –> everything is low except SVR which is compensating
cardiogenic shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: low
CVP: high
PCWP: high
SVR: high
SVO2: low
acute pump failure –> ineffective pump –> blood stays in the heart
septic shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: high then low
CVP: low then high
PCWP: low then high
SVR: low
SVO2: low then high
severe hypotension in response to infection
Similar to the other types of distributive shock, everything is low
anaphylactic shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: low
CVP: low
PCWP: low
SVR: low
SVO2: low
ALLergen –> ALL values are low
Similar to the other types of distributive shock, everything is low
neurogenic shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: low
CVP: low
PCWP: low
SVR: low
SVO2: low
Similar to the other types of distributive shock, everything is low
obstructive shock: labs
-CO/CI
-CVP
-PCWP
-SVR
-SVO2
CO/CI: low
CVP: high
PCWP: normal/low
SVR: high
SVO2: high
Blockage –> blood backs up into R ventricle –> R atrium (CVP high)
hypovolemic shock
results from a loss of >20% of circulating blood volume
hypovolemic shock: causes
internal/external bleeding
burns
DKA/HHNK
severe dehydration
hypovolemic shock: management
Isotonic fluids
vasopressors (e.g. norepinephrine, dopamine) and/or dobutamine (inotropic)
PRBC if H/H low
cardiogenic shock
a loss of effective contractile function results in impaired cardiac output, impaired oxygen delivery, and reduced tissue perfusion
(acute pump failure)
cardiogenic shock: causes
acute MI: most common cause
ventricular aneurysm
dysrhythmia
pericardial tamponade
hypoxemia
pulmonary edema
acute valvular regurgitation
acute ventricular septal defect
cardiogenic shock: management
initial, careful administration of fluids
vasopressor support (e.g. norepinephrine, dopamine) and/or dobutamine (inotropic)
distributive shock
three forms of shock characterized by massive vasodilation, decreased intravascular volume, reduced peripheral vascular resistance, and loss of capillary integrity
septic shock
Type of distributive shock
Severe hypotension in spite of adequate fluid resuscitation that is caused by the body’s overwhelming secondary response to infection
Septic shock: management
Fluid resuscitation
Blood cultures
Antibiotics within 1 hour
vasopressors (e.g. norepinephrine, dopamine) and/or dobutamine (inotropic)
anaphylactic shock
Type of distributive shock
IgE mediated reaction that occurs shortly after exposure to an allergen
anaphylactic shock: management
Maintain airway
Crystalloids for volume expansion
Benadryl 25-75mg IV or IM
Epinephrine 0.3-0.5 mg SQ or IM for respiratory distress
IV glucocorticoids as needed
Consider H2 antagonist (e.g. famotidine)
inhaled beta agonist for bronchospasm (e.g. albuterol)
neurogenic shock
type of distributive shock
Loss of peripheral vasomotor tone as a result of spinal cord injury, regional anesthesia, etc.
neurogenic shock: management
Maintain airway
crystalloids for volume expansion
vasopressors (e.g. phenylephrine, norepinephrine)
obstructive shock
inadequate cardiac output as a result of impaired ventricular filling
obstructive shock: causes
massive PE: most common cause
tension pneumothorax
acute cardiac tamponade
obstructed valvular disease
disease of pulmonary vasculature
obstructive shock: management
Maintain BP while treating underlying cause
fluid administration
vasopressors (e.g. norepinephrine)
mechanical ventilation as indicated
anticoagulation as indicated
toxic shock syndrome: pathogen
staphylococcus aureus
toxic shock syndrome: management
aggressive IV fluid hydration
fever control
empiric treatment with clindamycin and vancomycin
pressor support if needed
remove tampon
qSOFA criteria
1 point for each criteria; 2+ points near the onset of infection is associated with greater risk of death or prolonged ICU stay.
- low BP (SBP <100 mm Hg)
- high RR (>22)
- altered mentation (GCS <15)
cardiogenic shock: S/Sx
tachypnea, severe SOB
tachycardia, weak pulse
hypotension
LOC
diaphoresis
pallor
cold hands or feet
oliguria, anuria
hypovolemic shock: S/Sx
tachypnea
hypothermia
hypotension
tachycardia
confusion, anxiety, LOC
diaphoresis
cool skin
weakness
septic shock: S/Sx
tachycardia
hypothermia or fever
tachypnea, SOB
hypotension
shaking, chills
warm, clammy, or sweaty skin
confusion
lightheadedness
oliguria, anuria
palpitations
rash
anaphylactic shock: S/Sx
hypotension
tachycardia, weak pulse
wheezing, constriction of airways
urticaria, pruritis
flushed or pale skin
N/V/D
dizziness, LOC
neurogenic shock: S/Sx
hypotension
bradycardia
flushed, warm skin that gets cold and clammy later
circumoral cyanosis
LOC
obstructive shock: S/Sx
tachypnea
hypotension
tachycardia
Altered LOC
oliguria
cool, clammy skin
subcutaneous emphysema
chest, abdominal pain
refractory shock: criteria, management
SBP <90 for more than one hour following adequate fluid resuscitation and vasopressors
IV glucocorticoids are not routinely used as part of initial therapy and should be used on a case-by-case basis
-preferred medication: hydrocortisone alone
