Shock Flashcards
Why is hypotension bad
When blood isn’t circulating, there is no tissue perfusion
Give fluid bolus!
What is hypotension vs shock
Hypotension is low blood pressure
Shock is greater oxygen demand than oxygen supply
What can shock lead to
with little tissue perfusion, no oxygen delivery, cellular HYPOXIA and metabolic malfunction
Can lead to cell death; end organ damage; multi system organ failure; death
What is systemic tissue perfusion determined by
MAP= CO x SVR
CO is HR x SV
SVR is influenced by vessel length, diameter, and fluid viscosity
-CO and SVR determine the etiology of shock
What are the stages of shock
Pre-shock: warm, COMPENSATED. tachycardia, perish vasoconstriction, low BP
Shock: compensation OVERWHELMED, signs of organ dysfunction. tachy, dyspnea, metabolic acidosis, oliguria, cold clammy skin
End organ dysfunction: Progressive organ dysfunction, irreversible, coma, death
What are the types of shock
Hypovolemic, Cariogenic, Distributive
Obstructive, Neurogenic
What is an arterial line
line put into radial/brachial/femoral artery to continuously monitor BP and get recurrent ABGs
NOT for meds
What is a central line
placed in vein for delivering critical meds and measuring CVP.
Appropriate for determining fluid status and resuscitation in shock
Can get a triple lumen, double lumen, dialysis cath, Swan-Ganz cath, or PICC line
What is a Peripherally Inserted Central line Catheter (PICC)
Sits on top of the heart, small diameter, can keep for a long time but has increased DVT risk
What is CVP
pressure near the right atrium that correlated “pre-load” or overall volume status. Can be measured with any central line
If CVP is elevated (5-15 mmHg normal), probably don’t want to give many fluids
What is a Swan-Ganz catheter
goes through the RA, RV, and sits in the pulmonary artery. Good for patient in CARDIOGENIC shock
What hemodynamic parameters does a Swan-Ganz measure
Pulmonary capillary wedge pressure (norm 5-15)
Cardiac output (norm 4-8 L)
Systemic vascular resistance (norm 1000-1500)
What is the clinical presentation of all types of shock
Hypotension (SBP <90 or decrease >40)
Tachycardia (except neurogenic shock, brady)
Oliguria
Mental status change (confusion, lethargy)
Metabolic acidosis
Cold clammy skin (except early distributive and neurogenic- warm flushed)
Later: multi organ failure, coagulopathy
What happens in Hypovolemic shock
not enough intravascular volume causes decreased CO and decreased oxygen delivery
What are the causes of hypovolemic shock
hemorrhagic (trauma, GI bleed, internal hemorrhage, post-surgical) Fluid loss (dehydration, n/v/d, burns, acute pancreatitis)
What is the pathophysiology of Hypovolemic shock
decreased blood volume leads to decreased SV
deceased SV leads to decreased CO and BP
decreased BP and volume leads to inadequate tissue perfusion (no oxygen)
Compensation: increased SVR (vessels constrict to shunt remaining blood from periphery to heart, lungs, etc)–baroreceptors sense low BP and activate SNS
Switch to Anaerobic metabolism
What are the hemodynamic parameters of hypovolemic shock
CVP: decreased
CO: decreased
SVR: increased
What does clinical presentation of hypovolemic shock depend on
Amount of blood loss: small is tolerated, large are not
Rate of loss: slow loss allows time for compensation, fast loss leads to shock s/s faster
What do hypovolemic shock patients present with complaints of
Hematemesis, hematochezia, melena N/v/d abdominal pain evidence of trauma Post-op
What are physical signs of hypovolemic shock
Dry oral mucosa
Hypotension, tachycardia, tachypnea, decreased JVP/CVP/urine output
Cold clammy extremities, decreased turgor
Confusion
(May be others with underlying pathology)
What diagnostic studies are needed for Hypovolemic shock
CBC, CMP, PT/INR (are they bleeding?) Lactate (marker of tissue perfusion, increase during ANaerobic perfusion) ABG CXR/ chest CT Abd XR/CT
What is increased lactate associated with
increased mortality
if high, there is not enough tissue perfusion
