Thermoregulation and pyrexia

Question 1

Conscious intelligence range =

Answer 1

35-40 degrees

Question 2

Usual core temp

Answer 2

37 degrees

Question 3

Diurnal variation

Answer 3

Temp reaches lowest point just fore wake and highest 12 hrs after

Question 4

Ex of intersex variation of temp

Answer 4

Females have +0.5 degrees during ovulation

Question 5

Ways to measure temperature:

Answer 5

• Mecury thermometer
• Ear
• Oesophagus
• Rectal
• Electrical skin probe

Question 6

Disadvantages of mecury thermometer

Answer 6

• not quick
• food and drink can effect
• difficult for children

Question 7

Ear thermometers measure the..

Answer 7

Typanic membrane

Question 8

Thermistor and rectal thermometers are used when

Answer 8

Patient is asleep (ICU)

Question 9

Thermoreceptors are mainly found:

Answer 9

• Skin (peripheral)
• GI tract
• Great veins
• Hypothalamus (central)

Question 10

What kind of fibres are thermoreceptors?

Answer 10

Alpha delta

C

Question 11

Thermoreceptor fibers are:

Answer 11

• Slower

- Smaller diameter

Question 12

Fibres of thermoreceptors are the same as…

Answer 12

pain

Question 13

Coordinator of thermoregulation

Answer 13

Anterior hypothalamus

Question 14

Hypothalamus coordinates the

Answer 14

Set point

Question 15

Methods of heat production:

Answer 15

• Metabolic
• Voluntary
• Shivering
• Brown fat
• Vasoconstriction
• Neuroendocrine

Question 16

Enzymatic processes in the body are

Answer 16

Exothermic

Question 17

Voluntary actions to reduce heat loss are important in which groups of patients

Answer 17

Young people

Dementia etc.

Question 18

Why is shivering not a good method for certain patients?

Answer 18

Metabolically expensive. O2 consumption can increase.

Question 19

White fat =

Answer 19

Metabolically inert

Question 20

Brown fat has lots of

Answer 20

Mitochondria

Question 21

Where is brown fat found

Answer 21

Infants: Scapula, clavical, around main organs

Question 22

Paradoxical increased flow with prolonged cold exposure:

Answer 22

Cold –> vasoconstriction –> ischemia –> inflammatory products –> vasodilation –> more heat lost

Question 23

Neuroendocrine method of increasing heat:

Answer 23

• Increase catecholamines to increase metabolic activity

Question 24

Catecholamines ex:

Answer 24

Dopamine, adrenaline, noradrenaline

Question 25

Hyperthyroidism and temperature =

Answer 25

Not much increased temp unless grossly hyper

Question 26

Hypothyrodisim and temperature =

Answer 26

Not uncommon for this to make a patient hypothermic

Question 27

Methods of direct heat loss

Answer 27

- Conduction/convection - Radiation - Evaporation

Question 28

Definition of hypothermia:

Answer 28

Core of <35 degrees

Question 29

Severe hypothermia:

Answer 29

<28 degrees

Question 30

Causes of hypothermia

Answer 30

- behavioural - hypothyroid - dermatological

Question 31

Clinical features common to hypothermia and hyperthermia

Answer 31

Coma Confusion CV collapse

Question 32

Clinical features of hypothermia:

Answer 32

Confusion Coma CV collapse Increased change of arrthymias

Question 33

why is the chance of arrthymia increased with hypothermia

Answer 33

Catecholamine surge

Question 34

J wave:

Answer 34

Junctional wave on QRS complex. Hypothyroidism

Question 35

What causes J wave?

Answer 35

Abnormal cardiac replarisation because of low temp

Question 36

Management of hypothermia:

Answer 36

- ABC - Silver blanket - Controlled warming: hot air blankets, cardiac bypass

Question 37

Definition of hyperthermia:

Answer 37

>38 degrees

Question 38

Life-threatening hyperthermia:

Answer 38

40 degrees +

Question 39

Causes of hyperthermia:

Answer 39

Extertional Situational Drugs Pyrexia

Question 40

Clinical features of hyperthermia:

Answer 40

Confusion Coma CV collapse Seizures

Question 41

Pyrexia is due to =

Answer 41

Altered set point

Question 42

What causes 'chills'

Answer 42

Altered set point. Temp is high but body reacts to increase temp (shivering, goosebumps, vasoconstriction)

Question 43

Causes of PUO

Answer 43

``` Infection Blood transfusion of pyrogens Inflammation Malignancy Hypothalamic insults = bleed, inflammation ```

Question 44

PUO =

Answer 44

Pyrexia of unknown origin

Question 45

Major pyrogenic cytokines:

Answer 45

IL-1,IL-6, TNF, IFN

Question 46

Pyrogenic cytokines act to increase

Answer 46

Prostaglandins

Question 47

What acts on the hypothalamus to alter set point?

Answer 47

Prostaglandins

Question 48

Treatment of pyrexia:

Answer 48

``` Paracetamol NSAIDs Aspirin Cooling packs/ice Exposure Fan CPB (cardiopulmonary bypass) ```