Shock Flashcards
1. Explain concepts related to the assessment of an emergency department patient experiencing a shock emergency. 2. Describe various patient presentations related to shock emergencies. 3. List interventions necessary for a patient presenting with a shock emergency.
define shock
Shock is a state of impaired tissue perfusion resulting from circulatory failure brought on by various causes.
shock analogy to car
Gas = blood and plasma
Fuel pump = heart
Fuel line = arteries and veins
how is shock classified?
by the cause of inadequate perfusion
categories of shock
hypovolemic (low on gas)
cardiogenic (bad fuel pump)
distributive (fueling 2 cars with 1 gas line)
obstructive (blockage in fuel line)
cellular cascade in shock
similar for all causes of shock
–initially irreversible but w/o tx becomes irreversible
cell injury -> inflammation -> cell death
anaerobic metabolism -> glucose phosphorylation -> lactic acidosis
microvascular thrombosis -> depletion of clotting factors -> DIC
3 stages of shock
compensated
uncompensated
irreversible
compensated shock overview
Stage I or nonprogressive
compensatory mechanisms initiated
vital organs perfused
full recovery
uncompensated shock overview
Stage II or progressive
compensatory mechanisms inadequate
vital organs hypoperfused
recovery more difficult
irreversible shock overview
Stage III
compensatory mechanisms failed
cellular and organ death
refractory to tx
overview of physiological of compensated shock
SNS response
RAAS
ADH
intracellular fluid shift
SNS response in compensated shock
release of epi/norepi
vasoconstriction
increased HR, contractility, BP
RAAS in compensated shock
increased serum sodium
water reabsorption
decrease urine, increase BP and CO
ADH in compensated shock
renal reabsorption of sodium and water
decrease urine, increase BP and CO
intracellular fluid shift in compensated shock
increased intravascular volume
increase BP and CO
overview of physiology of uncompensated shock
altered capillary permeability respiratory insufficiency cardiac depression tissue hypoperfusion brain hypoperfusion
altered cap permeability in uncompensated shock
leakage into interstitial space
edema, decreased BP and perfusion
respiratory insufficiency in uncompensated shock
pulm edema
VQ mismatch
crackles, dyspnea, increased RR
cardiac depression in uncompensated shock
diminished venous return
ischemia of nonvital organs
decreased urine output increased lactate base deficit mixed venous sat (below 65%) cool skin decreased peripheral pulses
brain hypoperfusion in uncompensated shock
AMS
define hypovolemic shock
blood, plasma, or fluid loos reduces circulating blood volume and cardiac output
most common type of shock
common causes of hypovolemic shock
traumatic hemorrhage (long bone/pelvic fx, solid organ rupture, open wounds)
nontraumatic hemmorrhage
(GI bleed, ruptured AA, posterior epistaxis)
fluid shifts
(peritonitis, massive crush injuries, severe burns)
non-blood fluid loss
(v/d, diaphoresis)
urinary fluid loss
(DKA, diabetes insipidus, diuretic abuse)
hypovolemic shock assessment
ABCs cause labs trend VS MAP (above 60) (SBP + 2DP/3) urine output LOC
parameters of hypovolemic shock
blood loss HR BP RR urine output CNS
Class I of hypovolemic shock
blood loss below 15% HR below 100 BP normal RR 14-20 Urine above 30ml/hr CNS slightly anxious
Class II of hypovolemic shock
blood loss 15-30% HR 100-120 BP normal RR 20-30 Urine 20-30 ml/hr CNS mildly anxious
Class III of hypovolemic shock
blood loss 30-40% HR 120-140 BP decreased RR 30-40 urine output 5-20 ml/hr CNS anxious, confused
Class IV of hypovolemic shock
blood loss > 40% HR > 140 BP decreased RR > 35 urine output negligible CNS confused, lethargic
hypovolemic shock intervention overview
airway
control bleeding, reduce fluid loss
restore volume
blood replacement
fluid resuscitation in hypovolemic shock
- isotonic crystalloids (NS, LR)
- colloids
- blood replacement
define cardiogenic shock
inadequate tissue perfusion as a result of decreased CO despite adequate intravascular volume d/t myocardial pump failure
most common cause of cardiogenic shock
MI, particularly of L ventricular anterior wall
other causes of cardiogenic shock
MI, ischemia blunt cardiac trauma sustained dysrhythmias acute valvular dysfxn end stage cardiomyopathy
sx of cardiogenic shock
reflects heart failure, inadequate tissue perfusion
cardiac CP tachypnea, crackles, pulm edema tachycardia, tachydsrhythmias, S3 AMS pale, cool, clammy minimal urine output hypotension
cardiogenic shock assessment
ECG CXR ABG echo CBC, platelets, BMP, LFTs, RFTs lactate SvO2 less than 65%
cardiogenic shock interventions
airway decrease preload increase contractility decrease afterload cardiac catheterization angioplasty treat dysrhythmias
airway in managing cardiogenic shock
PEEP to force pulmonary edema fluid out of lung interstitium
how to decrease preload in cardiogenic shock
semi-fowler or fowler
nitro
diuretics
morphine
how to increase contractility in cardiogenic shock
positive inotropes (dobutamine) intra-aortic balloon pump
how to decrease afterload in cardiogenic shock
continuous nitro
nitroprusside
antiHTN
definitive tx for cardiogenic shock
cardiac cath
angioplasty
treat dysrhythmias
define distributive shock
abnormal distribution of intravascular volume as a result of
- decreased sympathetic tone
- increased vascular permeability
- pooling of blood in venous, capillary beds
types of distributive shock
anaphylactic
septic
neurogenic
define anaphylactic shock
acute, life-threatening allergic rxn in individuals exposed to antigen to which they have previously become hypersensitive
common antigens in anaphylactic shock
shellfish peanuts/tree nuts milk, eggs, wheat, soy food additives insects meds, latex, iodine
unusual causes of anaphylaxis
exposure to cold
exercise
difference between anaphylaxis and anaphylactic shock
anaphylaxis: normal circulation with risk of progression to shock
anaphylactic shock: shock state with compromised circulation
anaphylaxis vs anaphylactoid rxns
anaphylaxis IgE mediated and requires prior antigen exposure
pathophysiology of anaphylactic shock
antigen re-exposure hypersensitive antibody response vasoactive mediator release massive vasodilation profound hypovolemia increased cap permeability, fluid shift, vascular collapse
anaphylactic shock assessment
rapidly progressing sx
onset begins with cutaneous manifestation
urticaria, erythema, pruritis dypsnea, cough throat tightness, stridor wheezing, bronchospasm syncope chest tightness, palpitations angioedema hypotension, tachycardia respiratory, cardiac arrest
anaphylactic shock interventions
remove antigen IM epi 1:1000, rpt in 15-20 min airway high-flow O2 IV fluid reusc vasopressors for hypotension IV epi inhaled beta-2 agonists (albuterol) antihistamine (H1 and H2) corticosteroids admission epi teaching
define SIRS
cluster of sx of systemic inflammation
w/ or w/o infection
can be seen w/ acute pancreatitis, major trauma, burns
define sepsis
2 SIRS criteria w/ known/suspected infection
define severe sepsis
sepsis with organ dysfxn
cardiovascular failure -> hypotension
resp failure -> hypoxia
renal failure -> oliguria/azotemia
hematologic failure -> coagulopathy
define septic shock
sepsis with hypotension despite adequate fluid resuscitation
MODS
multiple organ dysfxn syndrome
progressive failure of initially uninvolved distant organs following severe infectious or noninfectious insults
sx of septic shock
mentation skin HR RR urine output acid/base values temp
sx of hyperdynamic (warm) sepsis
CNS malaise, tired, restless skin warm, flushed, dry HR elevated, full pulses RR > 20/min urine output decreased acid/base respiratory alkalosis temp fever, shaking, chills
sx of hypodynamic (cold) sepsis
CNS decreasing LOC, stupor, coma skin cold, clammy, pale mottled HR tachycardia, weak, thready pulses RR tachypneic, shallow urine decreased, anuria acid/base metabolic and resp alkalosis temp hypothermic, mottled
septic shock interventions
fluid resuscitation positive inotropes, vasopressors remove infectious sources wound, blood cultures ABXs
define neurogenic shock
loss of sympathetic stimulation, resulting in pure parasympathetic stimulation
massive vasodilation
body unable to compensate for drop in CO
causes of neurogenic shock
spinal cord injury above T6
spinal anesthesia
brain injury
sx of neurogenic shock
parasympathetic (rest/digest) is unopposed
bradycardia bradypnea hypotension warm, dry, flushed full pulses priapism
neurogenic shock interventions
ABCs to prevent secondary cord injury
fluids resuscitation
vasopressors
atropine
define obstructive shock
cardiac output and tissue perfusion are inadequate because of resistance to ventricular filling
causes of obstructive shock
pericardial tamponade
tension pneumothorax
PE
interventions for obstructive shock
correct underlying condition
tamponade: pericardiocentesis and surgery
tension pneumo: needle thoracotomy and chest tube
PE: anticoagulation or thrombolytics
incidence of pediatric shock
hypovolemia most common
septic shock also seen, especially in neonates, due to immature immune system
cardiogenic shock d/t toxic ingestion or sustained VT
hypovolemic shock in pediatrics
higher metabolic rate
higher body surface to volume ratio
inability to voice sx
assessing pediatric shock
dry mucous membranes no tears poor skin turgor sunken fontanels delayed cap refill child abuse IV/IO access
geriatric hypovolemic shock
prone to dehydration meds, diuretics decreased thirst response limited mobility use caution with fluid resuscitation
geriatric septic shock
pneumonia, urosepsis
AMS
respiratory alkalosis
normotheria or hypothermia