Shock

Question 1

Central venous pressure (CVP)

Answer 1

A measurement of pressure exerted by fluid in the right atrium.
Indicated right sided heart function
Normal 0-6mmhg
* Increased= Increase in the amount of fluid in the right atrium such as fluid overload, cardiogenic shock, RV failure/infarct, chronic LV failure, triscupid insufficiency, pulm HTN/copd, cardiac tamponade, PEEP
* Decreased= Decrease in the amount of fluid in the right atrium such as hypovolemia, vasodilation, distributive shock.

Question 2

Mean arterial pressure (MAP)

Answer 2

SBP+2(DBP)/3
Indicates the average driving force in the arterial system thorughout the cardiac cycle.

Question 3

Pulmonary arterial pressure (PAP)

Answer 3

A measure of the systolid and diasolic pressures in the pulmonary artery.
Normal: 15-25/5-15
* Increased: Conditions that cause an increase in the amount of fluid in the pulm artery or conditions that decrease the eleasticity of the pulm artery such as fluid overload, congential atrial and ventricular defects, pulm problems (COPD, asthma, emphysema), mitral valve regurgitation/stenosis, LV failure.
* Decreased: Conditions that cause a decrease in the amount of fluid in the pulm artery such as hypovolemia, decreased preload.

Question 4

Right ventricular pressure (RVP)

Answer 4

Measured during insertion of swan, no dicrotic notch. Notch is on ascending side (anacrotic notch, indicates atrial kick).
Normal: 20-30/0-5
Increased: RV failure/chronic CHF, pulm HTN/hypoxemia, cardiac tamponade.

Question 5

Pulmonary capillary wedge pressure (PCWP)

Answer 5

Also known as pulmonary artery occlusion pressure (PAOP)
A measure of the pressure of the left ventricle at end diastolic (max stretch).
Normal =6-12
* Increased: Conditions that increase the pressure in the left ventricle at end diastole such as fluid overload, decreased elasticity of the ventricle (LV failure), mitral valve disease, cardiac tamponade.
* Decreased: Conditions that decrease the pressure in the left ventricle at end diastole such as hypovolemia and vasodilatory medications.

Question 6

Cardiac output (CO)

Answer 6

The amount of fluid in L/min that the heart pumps into systemic circulation.
HR x SV = CO
Normal 4-8
* Increased: By factors that increase the HR or increase the amount of blood that the heart puts out with each beat such as excess fluids or inotropic agents.
* Decreased: By factors that decrease heart rate or decrease the amount of blood that the heart puts out with each beat such as hypovolemia and drugs that decrease contractility.

Question 7

Cardiac index (CI)

Answer 7

Normal 2-4
The cardiac output/body surface area.
More accurate measurement that CO due to the whole body surface area being taken into account.
Reflect CO to BMI

Question 8

Systemic vascular resistance (SVR)

Answer 8

Normal 800-1200
The resistance provided by the systemic circulation against which the left ventricle must pump blood.
(MAP - CVP) x 80/ CO
* Increased: sympathetic stimulation, vasocontriction, hypothermia
* Decreased: vasodilators, epidural anesthesia, hyperthermia.

Question 9

Mixed venous O2 saturation (SVO2)

Answer 9

Continuous display of mixed venous oxygen saturation by the pulm artery catheter.
Assesses effectiveness of peripheral oxygen delivery.
Normal 60%-80%
<60: Right shift, decreased affinity. Increased oxygen tissue extration of O2.
Think raised:
Raised unloading of O2, raised acid, raised temp, raised 2,3,DPG, raised PaO2.
>80: Left shift, increased affinity. Decreased tissue extraction of oxygen.
Think low:
Low O2 release, low acids, low temps, low 2,3DPG, low PaO2.
Left shift is bad for pt.

Question 10

Hypovolemic shock

Answer 10

Results from a loss of >20% of circulating blood volume. Cool, moist skin and tachy.
* Caused by: Internal/external bleeding, burns, DKA, HHS, severe dehydration.
* Labs/diagnostics: Low CO/CI, low CVP, low PCWP, increased SVR, low SVO2
* Management: fluid resuscitation, vasopressor support, PRBCs

Question 11

What is shock?

Answer 11

A clinical syndrome of systemic hypotension, acidemia, and impairment of vital organ function resulting from tissue hypoperfusion.
1st treatment for anyone in shock is isotonic fluids

Question 12

Different shock states

Answer 12

• Hypovolemic
• Cardiogenic
• Obstructive
• Distributive
  -Septic
  -Anaphylactic
  -Neurogenic disorders

Question 13

Cardiogenic shock

Answer 13

A loss of effective contractile function results in impaired cardiac output, impaired oxygen delivery and reduced tissue perfusion. (MI, LV dysfunction)
* Caused by: Acute MI (most common), ventricular aneurysms, dysrhythmia, pericardial temponade, hypoxemia, pulmonary edema, acute valvular regurgitation, acute ventricular septal defect.
* Lab/diagnostics: Decrease CO/CI, increased CVP, increased PCWP, increased SVR, decreased SVO2.
* Management: Initial careful administration of fluids, vasoressor support (dobutamine, milrinone, epi, dopamine)

Vasodilating agents:
Nitroprusside (arterial and vein) decreases afterload
Nitroglycerin (vein) decreases preload

Question 14

Intraaortic baloon pump

Answer 14

Counter pulsation to increase pump efficiency.
Augments diastolic pressure to aid in end organ perfusion.
Increases coronary artery perfusion
Reduces afterload
Reduces myocardial oxygen demand.

Question 15

Obstructive shock

Answer 15

Extracardiac shock.
Due to obstruction of flow in the CV circuit and characterized by either impairment of diastolic filling or excessive afterload.
* Causes: Massive PE (most common), tension pneumo, high PEEP, acute cardiac tamponade, obstructed valvular disease, disease of pulmonary vasculature.
* Lab/diagnostics: Decrease CO/CI, high SVR, normal/decreased PCWP, increased CVP, SVO2 high
* Management: Maintain BP while initiating treatment of underlying cause (fluids), vasopressors, ventilate, anticoagulants.

Question 16

Distributive shock

Answer 16

Three forms of shock characterized by vasodilation, loss of vasomotor tone, resulting in venous pooling of blood and decreased venoug return, leading to decreased CO and inadequate tissue perfusion.
Includes septic, neurogenic, and anaphylactic.

Question 17

Septic shock

Answer 17

Caused by infective organisms which invade the bloodstream and alter vascular tone and cause life threatening organ dysfunction. Hypovolemia develops as a result of blood pooling in the microcirculation.
* Lab/diagnostics: increased CO, decreased CVP, decreased PCWP, decreased SVR, decreased SVO2.
* Management: Fluids (30ml/kg), antibiotics w/in 1 hour (two different antibiotics from two different classes), vasopressors.

No steroids unless fluids are not helping and adrenal insufficiency is suspected.

Question 18

qSOFA

Answer 18

Quick SOFA
Used to identify pts with suspected infection who are at greater risk for poor outomes.
Assign 1 point for each criteria met, the presence of 2 or more points new the onset of infection is associated with a greater risk of death or prolonged ICU stay.
-Low BP (systolic <100)
-High RR (>22)
-Altered mentation (GCS<15)

Question 19

Anaphylactic shock

Answer 19

IgE mediated reaction that occurs shortly after exposure to an allergen.
The result of an immediate hypersensitivity reaction with severe antibody/antigen response. Involves one or both features (respiratory difficulty and hypotension) and lead to decreased tissue perfusion and initiation of general shock response.
* Lab/diagnostics: decreased CO/CI, decreased CVP, decreased PCWP, decreased SVR, decreased SVO2
* Management: Manage airway, fluids, benadryl (25-75mg), epi (0.3-0.5mg), steroids as needed, H2 antagonists, albuterol.

Question 20

Neurogenic shock

Answer 20

Produced by a disturbance in the nervous system that causes massive vasodilation due to interruption in the loss of sympathetic innervation. Resulting from spinal cord injury and/or regional anesthesia.
Warm/dry skin and bradycardia.
* Lab/diagnostics: decreased CO/CI, decreased CVP, decreased PCWP, decreased SVR, decreased SVO2.
* Management: Maintain airway, fluids, vasopressors.