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Flashcards in Fever Deck (11):
1

What is the definition of fever?

depends on condition, diurnal variation etc.

for now consider: 37.8-37.9 (for sure >38)

2

What is the definition of fever in febrile neutropenia?

T>38.3 (oral)

or T>38 (>=1 hr)

3

What is the definition of fever in FUO (fever of unknown origin)?

T>= 38.3 on multiple readings over 3 weeks

no cause after investigations

4

On avg where does normal body temperature lie?

36.5-37 dc

5

What is fever?

What causes fever (pathway)?

an increase in the 'hypothalamic setpoint'

exogenous pyrogens (bacteria, LPS)--> activated leukocytes--> pyrogenic cytokines: IL-1, TNF, IFN, IL-6--> vascular endothelium (inc PGE2)--> inc in hypothalamic setpoint range --> dec. cutaneous bld flow (chills), shivering to generate heat, thermogenesis from brown fat

6

Survival of what 2 infx correlates with Tmax of fever?

1. Gram negative bacteremia

2. Spontaneous bacterial peritonitis

7

What are 2 examples of increased body temperature that are not fever?

1. Hyperthermia (hypothalamic setpoint unchanged): heat stroke, malignant hyperthermia, neuroleptic malignant syndrome

2. Hyperpyrexia (T>41): CNS hemorrhage

8

What is the Ddx for fever?

-infections
-non-infectious inflammatory disorders (autoimmune connective tissue diseases, auto-inflammatory/periodic fever syndromes)
-malignancy
-vascular thrombosis
-endocrine/metabolic disorders
-drugs/medications

9

How do most antipyretic work?

COX inhibitors (inhibit Arachidonic acid-->PGE2

10

What are common anti-pyretics?

-ASA (salicylates)
-acetominophen (Tylenol)
-NSAIDS (ibuprofen, naproxen)

-Corticosteroids--> many actions so DONT USE FOR FEVER

11

What are the rx for:
1. fever
2.hyperthermia
3.hyperpyrexia

1. fever (prolonged/severe): acetaminophen

2. hyperthermia: external cooling+specific therapy

3.hyperpyrexia: external cooling+anti-pyretics