Quiz 1

Question 1

What are the four types of hormones?

Answer 1

1. Protein/Peptide hormones
2. Thyroid hormones
3. Catecholamines
4. Steroid hormones

Question 2

T/F: Positive feedback mechanisms control most hormone activity?

Answer 2

False; Negative feedback mechanisms

Question 3

What does homeothermic mean?

Answer 3

We actively maintain our body temperature in a tight range

Question 4

What temp do we typically maintain our temperature in?

Answer 4

36.5 to 37.3

Question 5

Which two temperature monitoring modalities reflect brain temperature?

Answer 5

1. Nasopharyngeal

2. External Auditory meatus

Question 6

T/F: The skin temp is typically the same as core body temp?

Answer 6

False; usually 3-4 C lower than core body temp

Question 7

By definition, what is hypothermia and hyperthermia?

Answer 7

Hypothermia is <36C

Hyperthermia is >38C

Question 8

What mediates temperature regulation?

Answer 8

Anterior hypothalamus/peoptic nuclei

Question 9

What are the vascular effects of hypothermia?

Answer 9

Vasoconstriction, hypoperfusion of tissues, pulse oximetry difficulty

Question 10

What are the cardiac effects of hypothermia?

Answer 10

Shivering=increase MVO2, MI, arrhythmias, J Wave (ST elevation), VF.

Question 11

At what temperature does defibrillation become unsuccessful typically?

Answer 11

Under 30C

Question 12

At what temperature does VFIB typically occus?

Answer 12

@ 22-23C

Question 13

How much does shivering increase MVO2?

Answer 13

300%

Question 14

What are the pulmonary effects of hypothermia?

Answer 14

PVR increases, ventilatory drive is depressed, CO2 increases

Question 15

What are renal effects of hypothermia?

Answer 15

Cold diuresis, decreases plasma volume

Question 16

What are hepatic effects of hypothermia?

Answer 16

Decreases hepatic blood flow.

Question 17

What are CNS effects of hypothermia?

Answer 17

Cerebral O2 consumption decreased, MAC decreases, delayed emergence, drowsiness, confusion

Question 18

T/F: MAC increases 10% per 1 degree C decrease?

Answer 18

False; MAC decreases 5-7% per 1C decrease

Question 19

What are hematologic changes with hypothermia?

Answer 19

Impaired platelet function, decreased platelet count, coagulation factors inhibited.

Question 20

By how much is drug metabolism reduced at 30C? 25C?

Answer 20

50% at 30C

60% at 25C

Question 21

Why does hypothermia=increased infections?

Answer 21

1. Decreased peripheral perfusion
2. Decrease cutaneous perfusion
3. Less penetration of ABX
4. Decreased phagocytic activity and impairment of neutrophil function

Question 22

What is included in the core compartment?

Answer 22

1. Major thoracic organs
2. Major abdominal organs
3. Brain

Question 23

What is included in the peripheral compartment?

Answer 23

1. Limbs
2. Skin
3. Subcutaneous tissue

Question 24

How is the body’s heat content distributed between the two compartments?

Answer 24

1/3 in the peripheral compartment and 2/3 in the core compartment

Question 25

What major way is difference between core and peripheral body temperatures maintained/changed?

Answer 25

Through vasoconstriction

Question 26

What is the principal byproduct of metabolism?

Answer 26

Heat production

Question 27

What accounts for 60% of heat loss?

Answer 27

Radiation

Question 28

What is the main factor related to radiation heat loss?

Answer 28

Temp difference between patient and environment

Question 29

What is defined as the heat loss from the layer of air next to skin that carries heat away from body?

Answer 29

Convection (wind chill)

Question 30

What two major factors are related to amount of heat loss via convection?

Answer 30

1. Body surface area exposed

2. Airflow

Question 31

Through which heat loss modality is ventilation/breathing heat loss?

Answer 31

Evaporation

Question 32

What is conduction?

Answer 32

Transfer of heat between adjacent surfaces

Question 33

Room temp crystalloid decreases body temp by how much?

Answer 33

0.25C for every liter

Question 34

In what three ways does GA cause hypothermia?

Answer 34

1. Promotes vasodilation
2. Decreases metabolic rate/heat production
3. Decreases hypothalamic responsiveness to hypothermia

Question 35

T/F: Neonates have decreased surface area to mass so they have less rapid heat loss?

Answer 35

False; neonates have INCREASED surface area to mass resulting in MORE rapid heat loss to the environment

Question 36

Basal Metabolic Rate decreases by how much with age?

Answer 36

Decreases by 1% per year beyond age 30

Question 37

How often does post-operative shivering occur?

Answer 37

40% of unwarmed patients after GA

Question 38

Post-operative shivering causes a ___ fold increase in myocardial events?

Answer 38

3 fold

Question 39

Why does post-operative shivering occur?

Answer 39

Induced by cooling of preoptic region of hypothalamus which causes the involuntary, oscillatory muscular activity to increase heat production.

Question 40

What is the best treatment of post-operative shivering?

Answer 40

Prevention

Question 41

What pharmacological treatment is available for post-operative shivering?

Answer 41

Demerol (meperidine).

Question 42

What are some causes of hyperthermia in OR?

Answer 42

1. MH
2. Sepsis/infection
3. Throtoxicosis
4. Pheochromocytoma
5. Hypothalmic lesion/trauma/anoxia

Question 43

In sepsis/infection, how does the body become hyperthermic?

Answer 43

Pyogens cause release of interleukin 1. This increases the set point for temperature in the hypothalamus.
Leads to heat conservation and heat production.

Question 44

In the infected/septic patient, how is heat conservation and heat production accomplished?

Answer 44

Vasoconstriction (heat conservation).

Shivering (heat production).