Endpoints of Resuscitation

Question 1

What is compensated shock?

Answer 1

When compensatory mechanisms such as increased heart rate, vasoconstriction, & increased oxygen extraction are activated in effort to preserve vital functions.

Question 2

What is uncompensated shock?

Answer 2

When compensatory mechanisms are exhausted & blood flow is compromised to vital organs.

Question 3

What are the traditional endpoints of shock resuscitation?

Answer 3

Blood pressure
Heart rate
Mental status
Urine output
Skin perfusion

Question 4

What are the global endpoints of shock resuscitation?

Answer 4

Oxygen delivery & consumption

Serum markers: 1) lactate 2) base deficit 3) Mixed venous O2 saturation 4) central venous O2 saturation

Question 5

What are the regional endpoints of shock resuscitation?

Answer 5

Gastric tonometry
Sublingual capnography
Near-infrared spectroscopy

Question 6

Normal arterial oxygen delivery (DO2)?

Answer 6

950-1150 mL/min, or 500-600 mL/min/m2

Question 7

Normal oxygen consumption (VO2)?

Answer 7

200-250 mL/min, or 120-160 mL/min/m2

Question 8

Base excess/deficit

Answer 8

The amount of base present in the blood

Question 9

Persistently elevated base deficit indicates…

Answer 9

…impaired oxygen utilization

Question 10

Lactate:

Answer 10

the metabolic byproduct of anaerobic metabolism

Question 11

In shock, lactate indicates…

Answer 11

…the presence of anaerobic metabolism & increasing oxygen debt due to decreased tissue perfusion

Question 12

Lactate levels from exertion (shivering or seizures) will normalize within what time frame?

Answer 12

30 minutes

Question 13

How is mixed venous O2 (SVO2) measured?

Answer 13

Via pulmonary artery catheter

Question 14

Mixed venous O2 (SVO2) reflects the venous O2 saturation from the following locations:

Answer 14

1) Inferior vena cava
2) Superior vena cava
3) Coronary sinus

Question 15

Normal SVO2

Answer 15

60-75%

Question 16

True or false: there is broad agreement that SVO2 benefits patients with shock.

Answer 16

False. “The value of using SVO2 remains controversial. Several studies have not shown any benefit to its use as a goal-directed endpoint in ICU patients. However, other studies have found that a low SVO2 is a predictor of poor prognosis.

Question 17

Central venous O2 (SCVO2) is normally [higher/lower] than mixed venous O2 (SVO2)

Answer 17

Lower

Question 18

In shock, SCVO2 has been found to overestimate SVO2 by what percentage?

Answer 18

5-18%

Question 19

Gastric tonometry is…

Answer 19

the measurement of CO2 in the gastric mucosa

Question 20

What causes increased CO2 in gastric mucosa?

Answer 20

Insufficient tissue perfusion/mucosal ischemia

Question 21

True or false: current mothods for assessing gastric PCO2 are easy & inexpensive.

Answer 21

False. “Currently available methods…are expensive & labor intensive. This may be one reason that gastric tonometry has never become a popular monitoring tool in clinical practice.”

Question 22

Sublingual capnometry is…

Answer 22

Measurement of sublingual PCO2 by use of handheld portable device.

Question 23

Which was found to be more predictive of outcomes: SVO2 or sublingual PCO2?

Answer 23

Sublingual PCO2

Question 24

Near-infrared spectroscopy is…

Answer 24

Continuous non-invasive technology used to determine tissue oxygen saturation, oxygen utilization at cellular level, & local tissue blood flow. May be used because near-infrared light passes through muscle, bone, skin with little attenuation

Question 25

True or False? Decreased thenar (palm of hand at base of thumb) StO2 reflects presence of severe hypoperfusion.

Answer 25

True.