Hemodynamics and Shock Lecture Powerpoint

Question 1

Shock definition

Answer 1

Physiologic state characterized by significant reduction in systemic tissue perfusion resulting in decreased oxygen delivery to the tissues, cellular hypoxia and derangement of local and eventually systemic biochemical processes

Question 2

Mean arterial blood pressure (avg between systolic and diastolic)=
Cardiac output =
Stroke volume =

Answer 2

• CO x SVR (systemic vascular resistance)
• HR x SV
• EDV-ESV

Question 3

Systemic vascular resistance definition and what two things determine it

Answer 3

Refers to resistance to blood flow offered by all of the systemic vasculature (not the pulmonary), determined primarily by changes in vessel diameter and blood viscosity

Question 4

Starling’s law

Answer 4

Amount of tension put on the ventricles by the filling of blood will correlate to the contractility generated by the ventricles

Question 5

-pressor drugs

Answer 5

Increase inotropic effect (contractility) when heart failing to deliver proper cardiac output

Question 6

Ejection fraction =

Answer 6

-SV/EDV

Question 7

Increased afterload will decrease ___ from the heart causing, over time, for the heart to ____

Answer 7

Stroke volume, hypertrophy

Question 8

5 categories of shock

Answer 8

• Cardiogenic (heart muscle problem)
• hypovolemic (due to hemorrhage or hypovolemia)
• anaphylactic (allergic mediated third space sequestering)
• septic (blood stream infection)
• Neurogenic (caused by damage to NS regulation)

Question 9

2 primary drugs for cardiogenic shock

Answer 9

Intense inotropes such as

• Dopamine
• dobutamine

Question 10

Dopamine at small, medium, and large doses effects

Answer 10

• Small renal vasodilation
• Medium increased inotropy of heart
• Large increase peripheral vascular resistance (vasoconstrict)

Question 11

Common causes of cardiomyopathy (3)

Answer 11

• viral infection
• alcohol induced
• pregnancy

Question 12

Beck’s triad

Answer 12

3 medical signs associated with cardiac tamponade

1) hypotension
2) JVD
3) muffled heart sounds

Question 13

During pneumothorax tracheal shift occurs to the ___ side

Answer 13

Contralateral

Question 14

Specific treatment to deal with cellular and mitochondrial poisons such as carbon monoxide

Answer 14

O2 saturation at a dive chamber

Question 15

4 Stages of shock

Answer 15

1) begins with inciting event
2) local then systemic circulatory abnormality
3) homeostatic mechanisms attempt to compensate until they are overwhelmed
4) progression culminates in irreversible end organ damage or death

Question 16

Preshock characteristics

Answer 16

Rapid compensation for diminished tissue perfusion by various homeostatic mechanisms, may be asymptomatic despite a 10% reduction in total effective arterial blood volume, eventually become tachycardic, see peripheral vasoconstriction, and modest changes in blood pressure

Question 17

Shock chracteristics

Answer 17

-Symptoms of organ dysfunction appear, tachycardia, dyspnea, restlessness, metabolic acidosis, cool or clammy skin

Question 18

Cardinal findings of shock (5)

Answer 18

• hypotension (dropped more than 40mmHg)
• oliguria
• mental status changes
• cool clammy skin
• metabolic acidosis

Question 19

End organ dysfunction characteristics (2)

Answer 19

• urine output declines

- restlessness evolves to agitation and coma

Question 20

Suggestive findings of hypovolemic shock (4)

Answer 20

• vomiting
• poor skin turgor
• dry mucosa
• decreased JVD

Question 21

Suggestive findings of cardiogenic shock (5)

Answer 21

• dyspnea
• chest pain
• palpitations
• pulmonary edema
• elevated cardiac biomarkers or ischemia on EKG

Question 22

Suggestive findings of “distributive” shock (anaphylactic, septic, neurogenic) (6)

Answer 22

• cough
• hematuria
• chills
• diaphoresis
• rash or hives
• tachycardia

Question 23

SIRS

Answer 23

Systemic inflammatory response syndrome, extreme physiological reaction to trauma, burns, or other things characterized by tachycardia, fever, rapid respiration, and abnormal WBC count that when in the presence of infection can result in sepsis

Question 24

Management of shock 4 principles

Answer 24

• stabilize respiration
• assess perfusion
• restore perfusion
• identify and control source of shock

Question 25

• Low preload requires…
• high preload requires…
• Increased SVR requires…
• Decreased contractility requires…

Answer 25

• …fluids
• …diuretics/venodilators
• …BP reduction (ACEI or ARB)
• …Positive inotropic agents such as dopamine, dobutamine, epi or norepi

Question 26

Increasing preload has what effect on contraction strength?

Increasing afterload has what impact on stroke volume?

Answer 26

• Increases contraction strength (frank starling law)

- Decreases stroke volume