Endocrine - Temperature managment

Question 1

Homeothermic means we actively maintain our body termperature in a tight range usually between

Answer 1

36.5 to 37.3

Question 2

Skin may be __ to __ degrees celsius lower than core body temperature

Answer 2

3 to 4

Question 3

The axilla is usually __ degrees celsius lower than core body temperature

Answer 3

1 degree

Question 4

Nasopharynx reflects _____ temp

Answer 4

brain

Question 5

External Auditory Meatus reflects _____ temp but there is risk of TM rupture

Answer 5

Brain

Question 6

Hypothermia

Answer 6

core body temperature is less than 36 Celsius

Question 7

Hyperthermia

Answer 7

rise in core body temperature >38 degrees celsius

Question 8

Normothermia

Answer 8

core body temperature 37 degrees +/- 1 degree

Question 9

Ambient temperature

Answer 9

temperature of the surroundings

Question 10

**What regulates the body temperature

Answer 10

the anterior hypothalmus / preoptic nuclei mediates temperature regulation

Question 11

Set point temperature

Answer 11

Body attempts to maintain a ceratin temperature

Question 12

**Hypothermia consequenees are extensive and _______ with degree of hypothermia

Answer 12

worsen

Question 13

**Vascular consequences of hypothermia

Answer 13

vasoconstriction, hypoperfusion of tissues, pulse oximetry difficult

Question 14

**Cardiac consequences of hypothermia

Answer 14

shivering increases oxygen consumption up to 300%, increased myocardial ischemia, increased cardiac morbidity, increased arrhythmias, Osborne of J wave (ST elevation), VF occurs @ 22-23 degrees Celsius, defib not successful below 30 degrees celsius, should resuscitate until rewarmed

Question 15

**Pulmonary consequences of hypothermia

Answer 15

PVR increases, ventilatory drive is depressed, C02 levels in blood decrease

Question 16

**Renal consequence of hypothermia

Answer 16

Cold diuresis, decreased plasma volume

Question 17

**Hepatic consequnce of hypothermia

Answer 17

Hepatic blood flow is decreased

Question 18

Will hypothermic patient be a slow wake-up?

Answer 18

SLOW

Question 19

Hypothermia results in ______ drug metabolism and elimination

Answer 19

reduced

Question 20

**For every degree celsius drop in temperature, MAC decreases ___ to ____%, meaning more gas has to come off before the patient will wake up

Answer 20

5 to 7%

Question 21

Hypothermia results directly in a diminished state of ________ and NMBs will be _______ in cold patients

Answer 21

consciousness / prolonged

Question 22

Hypothermic patients = _________ infections

Answer 22

increased

Question 23

Hypothermic patients have decreased peripheral perfusion, decreased cutaneous perfusion which results in _____ penetration of antibiotics to these areas. In addition there is decreased phagocytic activity and impairment in neutrophil function

Answer 23

less

Question 24

Prospective study of colorectal patients kept normothermic highlights

Answer 24

sutures removed 1 day earlier, 1/3 less infections, discharged from hospital 2.6 days earlier than nontreated group

Question 25

The peripheral compartment consists of

Answer 25

limbs, skin, subQ tissue AND has 1/3 of the body's heat content

Question 26

The core compartment consists of what?

Answer 26

major thoracic and abdominal organs and brain AND holds 2/3 of the body's heat content

Question 27

Cord body temperature is maintained within a narrow temperature range of?

Answer 27

36.6 - 37.4

Question 28

Peripheral body temperature varies widely from __ to ____ degrees celsius

Answer 28

0 to 40

Question 29

The difference between core and peripheral body temperatures is maintained by __________

Answer 29

vasoconstriction

Question 30

______ _______ from the body core to the skin provides heat transfer

Answer 30

blood flow

Question 31

The degree of heat conduction to the skin is controlled by the degree of _______ in the skin

Answer 31

vasoconstriction

Question 32

Vasoconstriction is controlled by the _____

Answer 32

SNS

Question 33

_______ production is the principal byproduct of metabolism

Answer 33

heat

Question 34

Heat production is increased by

Answer 34

exercise, shivering, non-shivering thermogenesis, hypermetabolic states (sepsis, thyroid storm), medications or hypothalmic lesioins

Question 35

Normal basal heat production would incerase a patients temp by ____ per hour if they werer completely insulated from heat loss

Answer 35

1.2 degree ceslsius

Question 36

**Shivering can increase heat production by ____%

Answer 36

300%

Question 37

Under normal conditions body heat is preserved by tonic _______ _____

Answer 37

peripheral vasoconstriction

Question 38

**Radiation heat loss

Answer 38

Loss of heat to cool surroundings via electromagnetic energy, major method of heat loss to environment, accounts for 60% of heat loss, determined by temp difference between patient and environment, also affected by exposed body surface area

Question 39

**Convection heat loss

Answer 39

wind chill, layer of air next to skin moves and carries heat away from body, can account for 25% of heat loss in OR's with forced airflow, degree depends on body surface area exposed and airflow

Question 40

Evaporation heat loss

Answer 40

loss of heat with skin prep solutions and in major surgeries with open abdominal cavities, normal respiration of inspired gases can account for evaporative losses, inspired gases are usually dry and moderately cool increasing heat loss

Question 41

Conduction heat loss

Answer 41

transfer of heat between adjacent surfaces (OR table), contributes <5% of heat loss, affected by temperature

Question 42

Anesthesia (both general and regional) _______ peripheral vasconstriction

Answer 42

inhibit

Question 43

In the first hour after induction of anesthesia there is a __ to ___ decreased in the core temp because of peripheral _______

Answer 43

1-1.5 degrees celsius / vasodilation

Question 44

Basic Metabolic Rate decreases ___ to _____% with general anesthesia decreasing heat production in the next 2-3 hrs

Answer 44

20-40%

Question 45

Initial heat losses slow as most significant and slow with ________ time

Answer 45

anesthetic

Question 46

Regional anesthesia (spinal or epidural) produce similar patterns of heat loss because of ________

Answer 46

vasodilation

Question 47

One unit of refrigerated blood or one liter of room temp crystalloid decrease core body temp by ____ degree celsius

Answer 47

0.25 degree celsius

Question 48

Cutaneous heat loss is proportional is proportional to exposed body surface area and accounts for ___% of heat loss

Answer 48

90%

Question 49

General anesthesia promotes vasodilation, decreases metabolic rate/heat production, and decrease hypothalmic responsiveness to ________

Answer 49

hypothermia

Question 50

Do NMBs prevent shivering?

Answer 50

Yes

Question 51

Heat loss becomes more pronounced with ___ and ______ patients

Answer 51

elderly and neonates

Question 52

Basic metabolic rate decreases approximately __% per year beyond age 30

Answer 52

1

Question 53

**Elderly and neonatal patients have diminished _____ _____ functioning which results in less vasoconstrictive heat conserving mechanisms

Answer 53

autonomic neural

Question 54

**Neonates have ____ surface area to mass resulting in more rapid ___ ____ to the environment

Answer 54

increased / heat loss

Question 55

Preoperative prevention of hypothermia

Answer 55

warm environment, insulate patient with blanket, actively warm so that peripheral body temp is warm, avoid sweating

Question 56

Intraoperative prevention and treatment of hypothermia

Answer 56

warm the OR, inuslate patient, forced warming, circulating water mattress, HME, cover exposed areas, used warm IVF, field irrigation with warm fluids, use low flow circuits, heating lamps for neonates, CPB warming

Question 57

Postoperative prevention and management of hypothermia

Answer 57

forced air warming, treatment of postop shivering

Question 58

**Post op shivering occurs in up to ___% of unwarmed patients after general anesthesia

Answer 58

40%

Question 59

**Causes dramatic increases in oxygen consumption and catecholamine release

Answer 59

shivering

Question 60

post-op shivering is associated with __ times increase in myocardial events

Answer 60

3 times

Question 61

Post op shivering is induced by cooling of preooptic region of _______ which causes the involuntary, oscillatory muscular activity to increase heat production

Answer 61

hypothalmus

Question 62

Treatment of postoperative shivering

Answer 62

prevention is preferable, demerol is the most commonly used agent for post operative shivering

Question 63

Demerol is the most commonly used agent for post operative shivering because….

Answer 63

effective, partially mediated by kappa opiod receptors, decreases shivering threshold twice as much as vasoconstriction

Question 64

Hyperthermia is relatively _______ in OR

Answer 64

uncommon

Question 65

Causes of Hyperthermia that should be ruled out

Answer 65

MH, sepsis/infection, thyrotoxicosis, pheocromocytoma, hypothalmic lesion, trauma, anoxia, neuroleptic malignant syndrome, transfusion reactions, medications

Question 66

With infection/sepsis - during bacteremia, pyogens cause release of _______ ______, increasing set point for temperature in the hypothalmus. This leads to heat conservation (vasconstriction) and increased heat production (shivering)

Answer 66

interleukin one

Question 67

**Malignant hyperthermia initially manifests as a _______ state with tachycardia, hypercapnia, muscle rigidity, tachyarrhythmias, metabolic acidosis. Treatment includes discontinuing triggering agents, administering dantrolene, active cooling, adequate hydration, and supportive care

Answer 67

hypercatabolic

Question 68

Hyperthermia treatment

Answer 68

Preop: Acetaminophen Intraop: cooling the OR, forced air cooling, cooled IVF, field irrigation with cold fluids, NG or Bladder irrigation with cooled fluids Postop: forced air cooling