Flashcards in Fever Deck (11):
What is the definition of fever?
depends on condition, diurnal variation etc.
for now consider: 37.8-37.9 (for sure >38)
What is the definition of fever in febrile neutropenia?
or T>38 (>=1 hr)
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
On avg where does normal body temperature lie?
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
Survival of what 2 infx correlates with Tmax of fever?
1. Gram negative bacteremia
2. Spontaneous bacterial peritonitis
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
What is the Ddx for fever?
-non-infectious inflammatory disorders (autoimmune connective tissue diseases, auto-inflammatory/periodic fever syndromes)
How do most antipyretic work?
COX inhibitors (inhibit Arachidonic acid-->PGE2
What are common anti-pyretics?
-NSAIDS (ibuprofen, naproxen)
-Corticosteroids--> many actions so DONT USE FOR FEVER