Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathophysiology CVP 622 > Test 1 content-Temp management > Flashcards

Test 1 content-Temp management Flashcards

1
Q

What is the basic definition of hypothermia?

A

Hypothermia is defined as a body temp below 35 degrees celsius. Or a state in which the body temp of a homeothermic mammal is below normal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Humans are effective system that ensures body temp remains near ____ degrees regardless of environmental factors

A

37 degress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is cold sensed?

A

By thermoregulators in the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When cold is sensed what happens?

A
  • Hypothalumus triggers strong sympathetic nerve response
  • Vasoconstriction of skin vessels
  • decreases convective heat loss
  • Skeletal muscle beds vasodialate
  • Increasing (augmenting) muscle activity to produce heat
  • This is done through tensing and shivering
  • Then the endocrine system is activated causing increased O2 consumption, heart rate, cardiac output and blood pressure is elevated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

4 categories and temps of hypothermia

A
  • Mild: (32-35 C)
  • Moderate (26-31 C)
  • Deep (20-25 C)
  • Profound: (below 20 C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Things associated with hypothermia

A
  • Reduction of metabolic rate
  • Reduction in O2 consumption
  • Lower pump flows
  • Less blood trauma-(flowing less cause it doesn’t put as much trauma on cells)
  • Preservation of phosphate stores and reduction of excitatory neurotransmitter release)(cns protection)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the hypothermia Q10 concept?

A

Each 10 degree C drop in body temp will decrease metabolic process by 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Example of hypothermia Q10 concept @ 37, 27, and 17 degrees C

A

37 degrees-Normal metabolism
27 degrees-50% reduction in metabolism
17 degrees-75% reduction in metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the normal values for pH and Pco2 @ 37 C?

A

pH-7.40

Pco2-40mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The solubility of gases in biologic fluids ______ with hypothermia

A

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

At a constant Co2 content, PaCO2 _______ as temperature falls.

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hypothermia _____ solubility

A

Increases. Co2 is 30x more soluble than O2. Inverse relationship (temp & gas solubility)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

With hypothermia there is _____ affinity of hemoglobin with O2

A

Increased

  • Left shift of oxygen-hemoglobin dissociation curve
  • Less 02 released to tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Hypothermia _____ CO2 production

A

Decreases.

  • Decrease in metabolism decreases CO2 production
  • Becomes important in blood gas management strategies at lower temps.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

As it gets colder ____ hemoglobin goes to tissue

A

Less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hemoglobin holds on to tissues more when ______ because metabolic demand is down

A

Colder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

O2 Hemoglobin dissociation for left shift

A

⬇️Temp ⬇️Hydrogen Ions ⬇️ Pco2 ⬇️2, 3 DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

O2 Hemoglobin dissociation for right shift

A

⬆️Temp ⬆️Hydrogen ion ⬆️Pco2 ⬆️2,3 DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If DPG is up than oxygen affinity is ______**

A

Down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hypothermia causes a _____ in blood flow to all vascular beds in proportion to the reduced metabolic demands

A

Decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What type of muscle sees the greatest reduction in blood flow during hypothermia?

A

Skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

During hypothermia the heart will see a _____ rate but contractility remains unchanged

A

Decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If DPG is down than oxygen affinity is ______**

A

Up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The myocardium is less/more sensitive at temps of 32 degrees?

A

More

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

During hypothermia the ____ see the largest proportional decrease in blood flow

A

Kidney’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

During hypothermia the liver (hepatic) will see a _____ in metabolic & excretory function

A

Decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How will the pulmonary system react in hypothermia?

A

*Progressive decrease in ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Hyperglycemia is caused by ____ insulin levels

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Hypoglycemia is caused by ______ insulin levels

A

High

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In hypothermia how is the endocrine system affected?

A
  • Hyperglycemia
  • Endogenous insulin production is decreased
  • Insulin administration is less effective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How would the sympathetic response be affected by hypothermia?

A
  • Increase in catecholamine production

* blood becomes more viscous and contributes to increase in vascular resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

T/F- Acid base balance is significantly affected by hypothermia

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Hypothermia ______ the tendency for weak acids and bases to dissociate in solution

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Maintenance of a constant ratio of [OH-] to [H] _____ as temp decreases

A

16:1

35
Q

Alpha stat regulation preserves the ratio of OH- to H+ with temperature change and produces an _______ shift with cooling

A

Alkaline shift

36
Q

pH stat regulation maintains an absolute constant of H+ regardless of temp and requires added ____, usually as CO2 with cooling

A

H+

  • CO2 is maintained at 40mmHG and pH at 7.40
  • So the total CO2 content is elevated
37
Q

Two different strategies for cooling a patient

A
  • pH stat

* Alpha stat

38
Q

During ________ cerebral blood flow is decreased, less chance of emboli to brain

A

Alpha stat

39
Q

______ is not temp corrected

A

Alpha stat

40
Q

Alpha stat appears advantageous in adults by _______ to the brain

A

Limiting micro emboli

41
Q

Ph stat may be beneficial in infants to ________ CBF (cerebral blood flow) and allow more efficient cooling

A

Increase

42
Q

Protection of the brain during deep hypothermia (temp <20 C) may be best accomplished with a mixed acid-base strategy: How?

A
  • pH-stat during initial cooling phase

* alpha-stat during reperfusion, rewarming, and termination of CPB (less blood flow going to brain in rewarming)

43
Q

Systemic temps less than ____ used to allow cessation of circulation for periods up to 40-60 mins

A

22 degrees C

44
Q

Asanguineous means _____

A

bloodless

45
Q

Pediatric cardiac surgery happens primarily in peds weighing ____

A

<8kg

46
Q

______ reduces metabolic demand of nervous system. Also, _____ lengthens period of tolerated ischemia

A

Hypothermia

47
Q

The ______ almost exclusively extracts energy through aerobic glycolysis

A

Brain

48
Q

During DHCA what organ is at greatest risk for injury? Metabolic activity is reduced, but never ceases

A

The brain

49
Q

Q(10) of 2.7 (20deg. C) predicts ____ arrest period of ___ minutes. However, ___ to ___ mins typically is tolerated

A

Safe, 15 mins

30-45 mins

50
Q

_____ degree gradient between perfusate and body temp for cooling

A

10-12 degree

51
Q

pH stat employed to dilate cerebral vessels to ensure what?

A

Uniform cooling of the brain

52
Q

When cooling patient down what is the proper gradient?

A

10-12 deg C.

53
Q

During DHCA you would monitor multiple sites, name the 5.

A

Nasopharangeal, tympanic, arterial, venous, bladder

54
Q

Employ ______ just prior to circ arrest by getting rid of excess ______ thereby decreasing/increasing intracellular pH

A

Alpha stat
Co2
Increasing

55
Q

T/F-During DHCA you would allow the patient’s blood volume to grain into the reservoir? Also, you would shut off pump stopping all circulation?

A

True

56
Q

What is exsanguination?

A

Process of draining or removing all blood

57
Q

_______ allows for vascular decompression as well as reducing static blood

A

Exsanguination

58
Q

Anesthesia gives these to preserve cell membrane

A

Steroids

59
Q

What are 3 things antegrade and retrograde cerebral perfusion do?

A
  • Replenishes with O2, substrate, and buffer
  • Washes out acid metabolites
  • Helps to maintain hypothermic brain temp
60
Q

Target temp for “safe” ischemic time?

A

18 deg C

61
Q

Rewarming after DHCA what would be the rewarm gradient range?

A

8-10 deg C between perfusate and body temp

62
Q

Rewarming after DHCA you would employ _______ to ameliorate CO2

A

strict alpha-stat

Definition of ameliorate-make (something bad or unsatisfactory) better.

63
Q

T/F- During rewarming you DO NOT want to dilate vasculature as needed

A

False- You will dilate vasculature as needed

64
Q

______ ensures global reperfusion of systemic vacular beds after DHCA

A

CPB rewarm

65
Q

What would you administer to counteract acidosis?

A

Bicarb (NaHCO3)

66
Q

T/F during rewarming it is not important to allow for adequate time to reach a sustained systemic temp-36 deg C

A

False! It is important to allow adequate time to reach 36 C

67
Q

DHCA deleterious effects

A
  • Cognitive degeneration (decreased intelligence & intellectual development)
  • Stroke
  • Brain death
  • Choreoathetosis (1-20% of children, basal ganglia injury)
  • Seizure (as witnessed on EEG and post-op)
68
Q

Definition of Deleterious

A

If something is deleterious, it does harm or makes things worse. Smoking has obvious deleterious effects on your health, not to mention your social life.

69
Q

______ occurs commonly after cardiac surgery and should be aggressively treated b/c it may worsen ischemic damage

A

HYPERthermia

70
Q

T/F-The arterial outlet underestimates cerebral temp

A

True

71
Q

It is important to limit your arterial outlet to <37 deg C to avoid _______

A

HYPERthermia

72
Q

When cooling, temp gradients between the arterial outlet and venous inlet should not exceed how many degrees? Why?

A

Should not exceed 10 deg C

Why?-To avoid generation of gaseous microemboli

73
Q

T/F-Oxygenator outlet temperature is surrogate for cerebral temp during CPB

A

True

74
Q

When arterial outlet blood temp is >/=30 deg C what gradient between arterial outlet and venous inflow should be maintained?

A

=4 degrees C

Maintain a rewarming rate of = 0.5 deg C/min

75
Q

Rewarming when arterial blood outlet temp is =30 deg C what gradient between arterial outlet temp and venous inflow should be maintained?

A

Maintain a max gradient of 10 deg C

76
Q

T/F-Pulmonary artery or nasopharyngeal temp recordings are reasonable for weaning

A

True

77
Q

What is the gold standard in temp monitoring?

A

Jugular bulb (JB)

78
Q

What 3 types of temp recordings correlate with JB monitoring?

A
  • Arterial blood outlet temp
  • Pulmonary artery
  • Nasopharangeal temp
79
Q

What temp is not as accurate in CPB cause the patient is not making urine, and not used when they are cold.

A

Bladder temp

80
Q

About how many die annually of SCD sudden cardiac death? And what percent of SCD are associated with CAD?

A

450,000

70%

81
Q

Hypothermic therapy increases/decreases the reperfusion injury associated with return of spontaneous circulation (ROSC)

A

Decreases

82
Q

What are 5 mechanisms of thought involving therapeutic hypothermia?

A
  • Reduction of cerebral oxygen consumption, Glutamate production, and reactive oxygen species.
  • While maintaining cell membrane integrity and cellular homeostasis
83
Q

Complications of therapeutic hypothermia (5)

A

Bleeding, sepsis, arrhythmias, pancreatitis, and renal insufficiency

Pathophysiology CVP 622 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions