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1
Q

Heat is a form of what?

A

energy (kinetic energy)

2
Q

Heat can be transfered from a hotter substance to a colder one, but never what?

A

cold to hot

3
Q

what is the measured thermal state of a substance whch quantifies the energy distribution among the molecules in a system?

A

Temperature

4
Q

what properties of a substance change with temperature changes?

A

physical properties

5
Q

what is the standard unit of temperature?

A

kelvin

K

6
Q

***********

0 K= what C

0 C= what K

0 k = what

how do u convert C to K

A

-273.15 C

273 K

absolute 0

add 273.15

7
Q

what is 1 calorie

A

the amt of heat needed to raise the temp of 1 g of h20 by 1 degree C

8
Q

what occurs to kenetic energy during freezing and thawing

A

decreases when cools (freezing)

Increases when warms (thawing)

9
Q

The majority of the body's heat is locted where?

A

core

-brain

-thorax

- abdomen

10
Q

since core temp is the gold standard where are some common sites to measure this

A

pulm artery

esophagus

rectum

bladder

tympanic

11
Q

********************************

metabolic rate increases by ___ - _____% for each degree C increase in core temp

A

6-7%

12
Q

*******************************

CO increases by ________ per degree C

A

3L/min

13
Q

the body compensates for excessive heat loss by what 2 ways

A

-decreasing rate of loss

-increasing rate of heat production

14
Q

Heat is a product of what?

and thus heat can be increased by increasing what?

A

metabolism

metabolism

 

15
Q

what is an effective way of increasing metabolism?

A

shivering

16
Q

The down fall of shivering is an increase in O2 consumption by 400-500%, this emphesizes the importance of us doing what?

A

keeping out pt's warm to prevent stressful increases in metabolism

17
Q

What is non-shivering thermogenesis?

A

complex mechanism not involving ATP

triggers brown fat metabolism

18
Q

what effects does Anesthesia have on thermoregulation

A

-general and regional anesthesia blunt the normal thermoregulatory mechanism

- Potent inhaled agents cause vasodilation and disrupt normal hypothalmic shivering regulation

- inhalation agents, propofol induction, vasodilating drugs, and regional anesthetics induce vasodilation

- regional- heat loss due to loss of sympathetic tone

 

19
Q

The greatest decrease in core body temp occurs when during anesthesia

A

1st hour of operative time

20
Q

*********************************

4 routes of heat loss

A

Radiation

Convection

Conduction

Evaporation

21
Q

*******************

most heat is lost from the body by what route

A

Radiation

22
Q

********************************

Burn pt's lose the highest % of heat by what route

A

Evaporation

23
Q

*******************************

What route is the transfer of heat energy by emission of infra-red radiation (energy) to the surrounding walls, equip, floor...etc

give ex

A

radiation

Heat just leaves your body

stop by placing a blanket on pt

24
Q

 *****************

what type of heat loss is the transfer of thermal energy by heating air adjacent to the skin, it increases kinetic energy expands, becoming less dense and rises carrying heat away

give ex

A

Convection

air currents pass by and remove the heat, we literally blow it away

in pool and water finally gets warm then u move and it is cold again,

 

 

 

25
Q

WHat type of heat loss is the loss of heat (transfer) by direct contact with a less hot substance

give ex

A

Conduction

when u sit in a chair and get up the chair is hot from your ass

the good thing is the heat can be maintained by the contact

26
Q

*****************

what type of heat loss is due to loss of latent heat of vaporization of moisture on the skin. Thi is limited by the gradient of skin H2O to atmospheric H2O difference

give ex

A

Evaporation

sweating

27
Q

*************

What is the formula for evaporation

A

H20L+ Heat= H2OG

28
Q

******************************************************

What is Absolute humidity and how is it measured

A

the mass of water vapor in given volume of air

Grams (g)

29
Q

*******************************

what is relative humidity? and how is it written?

A

The RATIO of the mass of water vapor in a giver volume of air to the mass required to saturate that given volume of air at the same temp

percent (%)

actual H2O vapor / Max. potential H2O saturation

30
Q

why does relative humidity increase a the temperature falls?

A

b/c the saturate vapor pressure falls

31
Q

Fully saturated air at 370C cantains how much water

A

44mg/L

32
Q

How do we humidify gasses?

A

Foam noses

electrical humidifiers/ nebs

Soda lime

Moistened circuit

low dry gas flows

33
Q

what are risk factors for perioperative hypothermia

A

age increased

GA

regional Anesthesia

ASA III or IV

trauma

Low body fat

Endocrin D/O

OR temp

abd cases OPEN

Cold fluids

Length

High gas flows

34
Q

what is the #1 risk factor for periop hypothrmia

A

GA

35
Q

***************************

a temp of this causes what CV effects

**33-36oC

**32-33oC

<30oC

19-20oC

 

A

**Increased HR BP CO

**Decreased HR BP CO

bradycardia, v-fib

asystole

**important

36
Q

Hypothermia of renal, at temp < 33oC can cause what

A

polyuria

37
Q

Hypothermia effects of hematological system

A

HCT rises(from fluid shift interstitial)

increased coags (plt's are sequestered in spleen and liver)

38
Q

Methods of acheiving and maintaining perioperative normothermia

A

Circulating water matress

Heated humidifiers

*low fresh gas flows (decreases evaporation) 0.5-1 L/min

Metallic reflective blankets

heat and moister exchangers (artificial noses)

warm IV fluid

Ambient temp (increase room temp)

Forced air warming blankets (bair hugger)

39
Q

The easiest way to prevent heat loss is to stop what?

A

radiation

40
Q

More heat = more what?

A

kinetic energy

41
Q

Where does heat start at?

A

cellular level with ATP

42
Q

Heat is a product of what?

A

Metabolism

43
Q

what is a d/o of hypermetabolism (rare)

A

MH

44
Q

shivering increases O2 comsumption by how much

A

400-500%

45
Q

Brown fat metabolism occurs in primarimy whom

A

babies and neonates

46
Q

what is a great way you can reduce evaporation

A

use low gas flows

47
Q

**

fully saturated air at 370C contains how much water

 

A

44mg/L

(i also wrote 1g=ml i don't know why or what it ment)

48
Q

of the absolute humidity of gas in the lungs at 370C is 44mg/L what should happen if then is 350C

A

be less than 44

49
Q

the relative humidity of gas in the lungs is always what

A

100%

50
Q

970F is how much K

A

97-32 x 5/9=K

97-32=65

65 * 5=325

325/9=36.111111111

36.1+273.15=309.25 K

51
Q
A