Hypo+hyperthermia

Question 1

What is hypothermia?

Answer 1

A condition in which an organisms body temp drops below that required for normal metabolism and bodily functions.

Question 2

Temperature range for mild hypothermia

Answer 2

32 to 35

Question 3

Temperature range for moderate hypothermia?

Answer 3

28 to 32

Question 4

What is the range of temperature for severe hypothermia?

Answer 4

Anything less than 28

Question 5

Why is thermoregulation important?

Answer 5

Maintenance of body temp is important as all chemical reactions will only function adequately within a normal given temperature

Question 6

What is the role of the hypothalamus?

Answer 6

The hypothalamus reacts to signals from the thermoreceptors throughout the body in order to trigger heat production or heat loss mechanisms

Question 7

Where are the central thermoreceptors?

Answer 7

Hypothalamus, spinal cord, abdominal organs

Question 8

What are thermoregulatory controls?

Answer 8

Complex hormone pathways throughout the endocrine system that stimulate or inhibit the release of hormones into the blood stream to cause vasoconstriction/vasodilation.

Question 9

What are the mechanisms of heat loss?

Answer 9

Radiation, conduction, convection, and evaporation.

Question 10

What is radiation in the context of heat loss?

Answer 10

Body heat is lost to nearby objects without physically touching them

Question 11

What is convection in the context of heat loss?

Answer 11

Body heat is lost to surrounding air, which becomes warmer, rises, and is replaced with cooler air

Question 12

What is evaporation in the context of heat loss?

Answer 12

Body heat causes perspiration which is lost from the body surface when changed from liquid to vapour

Question 13

What is conduction in the context of heat loss?

Answer 13

Body heat is lost to nearby objects through direct physical touch

Question 14

Describe shivering thermogenisis

Answer 14

• The body’s mechanism in response to early hypothermia
• Core body temp drops and triggers the shivering reflex, causing involuntary muscle contractions
• Muscle groups around the vital organs begin to shake in small movements in an attempt to create warmth by expending energy, which is very effective in raising body temp.

Question 15

How does constriction of cutaneous blood vessels promote heat?

Answer 15

Works to reduce blood flow to the skin and therefore reduce heat loss.

Question 16

What is the process of increasing the metabolic rate (chemical thermogenesis)?

Answer 16

Hypothalamus -> anterior pituitary -> TSH -> thyroid hormone excretion -> increased BMR

Question 17

What is a respiratory effect of hypothermia?

Answer 17

Oxyhaemoglobin dissociated curve shifts to the left, impairing oxygen delivery to cells

Question 18

What is a cardiac effect of hypothermia?

Answer 18

As the heart cools it becomes at risk of developing arrhythmias and the VF threshold is lowered

Question 19

True or false: rough handling/sudden posture changes of hypothermic pts can trigger VF.

Answer 19

True

Question 20

How does hypothermia cause conflicting acid/base imbalances?

Answer 20

• Initial increased respiratory drive causes respiratory alkalosis
• Na/K pump dysfunction and lactic acid production from shivering and poor perfusion causes metabolic acidosis
• Decreased respiratory drive causes respiratory acidosis

Question 21

In the initial stages of hypothermia is there increased or decreased insulin production?

Answer 21

Increased, progressing to hypoglycaemia as reserves are depleted

Question 22

Which specialty populations are at increased risk of hypothermia?

Answer 22

Geriatrics and neonates

Question 23

What is circum-rescue collapse?

Answer 23

Rescue from cold stress in seemingly stable and conscious state, then to collapse soon after with symptoms from syncope to cardiac arrest

Question 24

Trauma pts are considered hypothermic at what temperature?

Answer 24

<36.0 degrees Celcius

Question 25

Why avoid active rewarming?

Answer 25

Warming extremities may cause warm blood to travel to a cold heart and cause pre-terminal arrhythmias

Question 26

At what temperature are resus drugs withheld?

Answer 26

<30 degrees Celcius

Question 27

In what temp range is drug administration interval altered, and how so?

Answer 27

Between 30 and 35 degrees Celcius, interval time is doubled

Question 28

Hypothermic pts below 30 degrees Celcius should always be shocked at which energy level?

Answer 28

360j

Question 29

After how many shocks to a hypothermic pt do you cease shocking, and until the pt reaches what temp?

Answer 29

After 3 shocks until the pt is over 30 degrees Celcius

Question 30

What is hyperthermia?

Answer 30

Elevated body temperature due to failed thermoregulation that occurs when a body produces or absorbs more heat than it dissipates

Question 31

What is heat exhaustion?

Answer 31

Where thermoregulatory control mechanisms are inefficient or attenuated

Question 32

What is exercise-related collapse?

Answer 32

Orthostatic hypotension that may be due to the loss of muscle pumping action caused by the cessation of exercise when combined with cutaneous vasodilation

Question 33

What is heatstroke?

Answer 33

A form of hypothermia with a systematic inflammatory response syndrome leading to multi-organ dysfunction

Question 34

What is the temp range of heat exhaustion?

Answer 34

> 38, <40

Question 35

What is the temp range of heat stroke?

Answer 35

> 40