Shock Flashcards
what is the definition of shock
ineffective delivery of oxygen to the tissue infective perfusion
what is the goal with shock
to optimize oxygen delivery amount
what are the 4 types of shock
hypovolemic, cardiogenic, obstructive, dstributive
what is hypovolemic shock
inadequate circulating volume -> decreased perfusion
what are common causes of hypovolemic shock
hemorrhage, v/d, third spacing loss
what is cardiogenic shock
results from heart failure, exclude factors outside the heart (only the heart this deals with)
-pumping function is severely impaired -> circulatory failure
what are some factors of cardiogenic shock
structural problems, arrhythmias, ineffective forward flow
what are the structural problems of cardiogenic shock
valvular insufficiency (back flow)
HCM - felines, diasystolic failure
DCM - canines, weakened contractions, poor contractility
what is obstructive shock
obstruction of blood flow from/returning to the heart -? diminished blood volume
what are some causes of obstructive shock
GDV, caval syndrome, pulmonary embolism, pericardial effusion/pneumothorax
what is distributive shock
flow maldistribution - vascular compartment expands (hypoperfusion despite adequate blood volume)
- loss of vessel tone
- injected mm
what are some potential causes of distributive shock
sepsis, SIRS, anaphylaxis, neurogenic disorder
what is SIRS
systemic inflammatory reponse
what are the clinical signs of systemic inflammation in response to infectious or noninfectious insults
trauma, pancreatitis, burns, venom, neoplasia, heart stroke
what is sepsis
the clinical syndrome caused by infection and the host’s systemic inflammatory response to it
(may be bacterial, viral, protozoal, or fungal origin)
what are the perfusion parameters
mentation, mm/crt, HR, pulse quality, extremity temp, BP
how is the shock index calculated
HR over systolic blood pressure, higher than 1 = patient in shock
what are the stages of shock
compensatory stage, early decompensatory stage, decompensatory stage (terminal)
what si the compensatory stagge
animal attempts to maintain O2 delivery to the tissue
what are the 2 responses in the compensatory stage
sympathetic and neurohormal
what is the sympathetic response in the compensatory stage
increased CO by increased HR and SV
what is the neurohormonal response in the compensatory stage
water retention and fluid shift from interstitial to intravascular space
what may happen in the compensatory stage
splenic contraction may occur to increase number of circulating RBCS, more RBCS = more oxygen to be able to be carried
what are the clinical signs of the compensatory stage
tachycardia, tachypnea, normal rec temp, normal to slow hypertensive, pink mm, cool extremities, normal mentation, prolonged CRT
if the compensatory stage is untreated due to inadequate intravasculcar volume what happens
decreased systemic vascular resistance, cardiac dysfunction, patient goes into early decompensatory
what are the clinical signs of the early decompensatory stage
tachycardia, prolonged CRT, weak pulse, pale mm, possible decrease in temp, decreasing BP< dull mentation (caused by lacatate acidosis)
what are the clinical signs of terminal stage/ late decompensatory stage
as a result of organ failure - bradycardia, pale/cyanotic mm, absent CRT, weak or no pulse, hypotheromic, anuria
what is the terminal stage
happens with the stage before is not treated effectively, severe intravascular volume loss, autoregulatory escape, multi-organ failure, sympathetic center of the brain doesnt work
what is the autoregulatory escape
local responses override sympathetic response, massive vasodilation in all organ - complete circulatory collapse
what is the early decompensatory stage
redistribution of blood flow to preferred organs (heart and brain), overwhelmed liver, myocardial depressant factor, hypoxia,lactic acid production
