Pathophysiology and Therapy of Shock Flashcards
what are the classic signs of shock?
tachycardia and increased pulse rate
tachypnea
pale and cool skin
mucous membrane pallor
delayed capillary refill time
reduced urine output
weak arterial pulses, abnormal pulse pressure
muscle weakness
pupillary dilation abnormal sensorium
what is the definition of shock?
clinical syndrome resulting when cardiac output is insufficient to fill the arterial tree with blood under sufficient pressure to provide organs and tissues with adequate blood flow
oxygen deficit to tissues
what characterizes shock?
reduced tissue perfusion
impaired oxygen delivery
inadequate cellular oxygen utilization
inadequate cellular energy production
what are the major mechanisms for lack of oxygen delivery/utilization to tissues (shock)?
inadequate blood volume
inadequate cardiac performance
inadequate vascular tone
tissue defect in oxygen utilization
what does higher sympathetic tone lead to?
faster heart rate
positive inotropy
positive chronotropy
increased vascular tone
what are some etiologies of shock?
hemorrhage/hypovolemic
traumatic
cardiogenic
septic
neurogenic
anaphylactic
what are the compensatory mechanisms from the sympathetic nervous system in shock?
increased heart rate
increased inotropy
vasoconstriction
increase blood pressure towards normal
hepatic glycogenolysis to increase blood glucose
what does the baroreceptor response in shock lead to?
increased cardiac output
what happens with the blood due to reduced cardiac output?
metabolic acidosis
elevated blood lactate
what do cats usually have in response to shock/critical illness?
bradycardia
hypothermia
hypoglycemia
what often happens in cardiogenic shock?
fluid volume typically excessive
ANP and BNP are elevated
jugular vein is distended
what is infection?
inflammatory response to the presence of microorganisms
what is endotoxemia?
endotoxin in the bloodstream
are fluids or diuretics indicated in cardiogenic shock?
diuretics often indicated
fluids often not indicated
what is septic shock?
severe sepsis with hypotension that is unresponsive to adequate fluid resuscitation
what criteria does an animal have to have 2/3 of to have systemic inflammatory response syndrome (SIRS)?
abnormal temperature
abnormal heart rate
tachypnea
leukocytosis, leukopenia, or significant left shift
what is multiple organ dysfunction syndrome (MODS)?
presence of organ dysfunction in 2 or more systems
how is cardiovascular dysfunction identified?
need for pressors
what is hypovolemic shock?
loss of circulating blood volume
what can cause hypovolemic shock?
hemorrhage
gastrointestinal losses
reduced intake of fluids
diuresis
third spacing of fluids
addison’s disease
what should you do after giving sufficient fluids if shock persists?
give pressors or inotropes
what is a shock dose of fluids for a dog and cat?
dog: 90 ml/kg in an hour
cat: 60 ml/kg in an hour
how should you bolus a dog with crystalloids in shock?
give bolus of 20 ml/kg, then reassess
repeat up to 3 times (80 ml/kg) then think about pressors, blood, colloids
what are the replacement fluid types?
0.9% NaCl
lactated ringer’s solution
plasmalyte A
do crystalloids stay in the intravascular space for long?
no
what is hypertonic saline used for?
very large animals
head trauma cases to minimize cerebral edema
maybe large breed dogs
what are some potential side effects of hypertonic saline?
hyperosmolarity
hemolysis
hypernatremia
hyperchloremia
hypotension or ventricular premature contractions if given too fast
what are colloids?
large, oncotically active particles
what do colloids maintain?
intravascular colloid osmotic pressure
how well do colloids persist in the intravascular space?
better than crystalloids
what is the total dose of colloids?
20 ml/kg
often 5 ml/kg boluses
why might you give fresh frozen plasma?
clotting factors
protein
what is cryoprecipitate?
clotting factors without the volume
what makes up frozen plasma?
protein