Exam #2: Hemodynamics V Flashcards
What is the definition of shock?
Inadequate perfusion i.e. inability of the circulatory system to adequately supply tissues with nutrients and remove toxic waste
Outline the sequela of shock.
Reduced cardiac output or reduced effective circulating volume leads to:
1) Hypotension
2) Impaired tissue perfusion
3) Hypoxia
List the different classifications of shock. What is the mnemonic to remember the etiological classifications of shock?
SSHHOCCKE
S= septic S= spinal/neurogenic H= hypovolemic H= hemorrhagic O= Obstructive C= Cardiogenic C= Cellular toxins K= AnaphylaKtic E= Endocrine/ adrenal crisis
Draw the mechanisms of shock.
N/A
What is the common endpoint of shock?
Cellular injury
What are the five unifying features of shock?
1) Intracellular Ca++ overload
2) Intracellular H+ ion
3) Cellular & intersitial edema
4) Catabolic metabolism
5) Inflammation
What is the manifestation of irreversible shock?
Multisystem organ failure, esp. kidney, liver, brain
What are Rosen’s Emperic criteria for the diagnosis of shock?
1) Ill appearance or decreased LOC
2) HR greater than 100
3) RR greater than 22 & decreased PCO2 less than 32 (Normal 35-45) i.e. respiratory alkalosis
4) Lactic acid above 4 or base deficit anuria)
6) Hypotension greater than 20 min. duration
What is base deficit?
Amount of base required to neutralize the pH (normal is -2)
What are the three stages of shock?
1) Nonprogressive stage
2) Progressive stage
3) Irreversible stage
What is the nonprogressive stage of shock?
Blood pressure & cardiac output are maintained via:
1) Baroreceptor reflex
2) Catecholamine release
3) Activation of RAA
4) ADH release
5) General sympathetic stimulation
What is the progressive stage of shock?
1) Widespread tissue hypoxia in the microcirculation
2) Lactic acidosis
3) Confusion and decreased urinary output
What is the irreversible stage of shock?
1) Widespread cell injury
2) Subsequent decrease in urine output and severe fluid/electrolye disorders occur
What is the mortality of shock dependent on?
Physiologic health?
Etiology of shock
Duration of shock
What are the morphologic features of shock in the brain?
Ischemic encephalopathy
What are the morphologic features of shock in the heart?
Coagulation necrosis
Subendocardial
What are the morphologic features of shock in the kidneys?
Acute tubular necrosis
What are the morphologic features of shock in the lungs?
Diffuse alveolar damage
What are the morphologic features of shock in the adrenal gland?
Cortical cell lipid depletion
What are the morphologic features of shock in the GI tract?
Mucosal hemorrhage & necrosis
What are the morphologic features of shock in the liver?
Fatty change, central hemorrhagic necrosis
What is the definition of cardiogenic shock?
Poor myocardial contractility
Outline the sequala of cardiogenic shock.
N/A
What are the diagnostic criteria for cardiogenic shock?
1) Hypotension
2) 30 mmHg below baseline
3) Cardiac index is lowered i.e. not enough CO to meet body need
4) Pulmonary Capillary Wedge Pressure >15mmHg*****
5) Rosen’s (4/6)
*****Swann cath.
How is cardiogenic shock treated?
1) ABCs
2) Id cause
3) Fluid bolus
4) Ionotropic/ vasopressor support
5) Manage infarct
Don’t be shy on fluids if RV infarct
What are the four different classes of hypovolemic shock classified?
I-IV
What is Class I hypovolemic shock?
<100
BP & PP normal
LOC= anxious
What is Class II hypovolemic shock?
750- 1500 mL lost HR 100-120 PP decreased BP normal LOC= anxious
What is Class III hypovolemic shock?
1500 - 2,000 mL lost HR 120- 140 PP decreased BP decreased LOC= confused
What is Class IV hypovolemic shock?
>2,000 mL lost HR > 140 PP decreased BP decreased LOC= lethargic
How is hypovolemic shock managed?
1) Crystalloid bolus
2) Blood transfusion
3) Identify and treat cause
What are colloids? What are the advantages & disadvantages?
Colloid solutions refer to solutions that are hypertonic due to the addition of some solute to the fluid
Advantages:
- Less fluid required
- More volume in the vascular space
- Shift fluid into vascular space from tissue
Disadvantages
- Expensive
- Allergic reactions can be mounted to solute
- Coagulopathies
Outline the pathophysiology of septic shock.
N/A
Outline the effects of cytokine induction.
N/A
What is the temproal progression of the cytokines?
LPS
TNF
IL-1
What are the criteria for the diagnosis of SIRS?
Temp > 38C or < 36C
HR >90
RR >20 or PaCOP2 12 or 10% bands
What is the definition of sepsis?
SIRS + documented infection
What is severe sepsis?
Sepsis + MODS (multi-organ dysfunction)
What is septic shock?
Sepsis + Hypotension refractory to volume resuscitation
What is one of the most crucial factors in treating septic shock?
Early and appropriate initiation of antibiotics antibiotics
What are some of the newer approaches to treating septic shock?
Vasoactive mediators
Coagulation Cascade
Inflammatory Mediators
What is the difference between spinal shock and neurogenic shock?
Spinal= loss of cord function following injury, including motor, sensory, and sympathetic function
Neurogenic= loss of sympathetic tone due to spinal cord injury
Neurogenic shock is usually seen in lesions at or above what level?
T6 & higher= vasodilation
T4 & higher= bradycardia
Outline the pathophysiology of neurogenic shock.
Hypotension
- Loss of tone= vasodilation
Bradycardia
- Unopposed vagal tone on the heart
Outline the pathophysiology of anaphylactic shock.
IgE mediated systemic vasodilation and increased vascular permeability–> shock
