Fever Flashcards
What is the Sn and Sp of tactile detection of a fever?
Sn 75-89%
Sp 56-85%
PPV 57-63%
Why its important to confirm with a recorded temp
Rectal in infants
When does the variation in body temp match the circadian rhythm?
2 years
Peak in the evening (1700-1900)
Trough in the early AM (0200-0600)
How is fever produced by the body?
Infection causes the release of exogenous pyrogens that interact with macrophages etc and produce cytokines which together act on the receptors of the anterior hypothalamus to produce prostaglandin and cause fever
Does bundling cause fever in infants?
It can
Do a 30-60 min period body equilibrium (unbundle) and then recheck the temp
Does teething cause fever?
Can cause mild temperature elevation
But teething has not be shown to be associated with temps > 38.5C
Is sponging effective to reduce a fever?
The theory is to bath a child to reduce the temp by evaporation
May take 20 min to work
Use tepid or room temp water so the child is comfortable and not cold and shivering
Never use cold water or isopropyl alcohol - cause excessive vasoconstriction and shivering which will increase metabolism and therefore temp
Name 4 fever myths
1) Fever causes brain damage
2) Fever reduction with antipyretics prevents febrile seizures and improves morbidity and mortality from fever
3) Response to antipyretics predicts the severity of the illness
4) Height of the fever indicates serious bacterial illness
What are the normal increase in HR and RR with each degree rise in temp?
10-15 bpm (HR) and 3-5 breaths/min (RR) for each degree rise in temp
Name 2 RF for fever being indicative of more serious illness
Young age (<2 months) Immunocompromised (diseases or meds)
Name 3 reasons we are more concerned with fever in young infants?
1) Risk of serious bacterial illness in this age group is relatively higher (~10%)
2) They have immature immune responses to keep infection contained
3) Clinical appearance is difficult to interpret
Name the 4 most common organisms for infection in febrile infants (< 1 month)
GBS
E coli
Listeria
Staph Aureus
GELS or LEGS
Maternally acquired bugs
Name the 4 most common organisms for infection in febrile infants (> 6 weeks)
Strep Pneumococcus
H flu
Influenza
Neiserria Meningococcus
SHIN
Community acquired bugs
Name the 4 most common organisms for infection in febrile infants (4-6 weeks)
Both maternally and community aquired bugs
LEGS SHIN
Listeria
E coli
GBS
Staph Aureus
Strep pneumo
H flu
Influenza
Neiserria Meningococcus
List 3 sets of low-risk criteria for febrile infants?
Boston
Philadelphia
Rochester
Name the specific parameters for each set of low-risk criteria
Boston Age (days) 28-89 Temp (C) > or = 38 WBC <20,000 Urine < 10 WBC/HPF CXR No infiltrate CSF (WBC/uL) <10
Philadelphia Age (days) 29-56 Temp (C) > or = 38.2 WBC <15,000 Urine < 10 WBC/HPF and no bacteria CXR No infiltrate CSF (WBC/uL) <8
Rochester Age (days) 0-60 Temp (C) > or = 38 WBC 5000-15000 Urine < 10 WBC/HPF CXR Not required CSF (WBC/uL) Not required
What are the Sn and NPV for each criteria
Boston - Sn unknown NPV 94.6%
Philadelphia - Sn 100 NPV 100
Rochester - Sn 92.4 NPV 98.9
What is a FSWU?
CBC
UA
LP
Cx - blood, urine, CSF
What is the most common type of bacterial infection in infants < 2 months?
UTI
What is occult bacteremia?
Unsuspected bacteria in the blood
Well appearing child, no focus, bacteria in the blood
Are WBC and CRP good predictors of serious infection?
No
Procalcitonin is better
What bug are you worried about when you see a petechial rash?
N meningiditis
Petechial rash makes you think of a more serious invasive bacterial infection
Other possibilities: S. pneumococcus GAS S. aureus E. coli Rickettsia
What is the definition of fever without an origin/unknown origin (FUO)?
Fever with no focus x 3 or more weeks
Sometimes can be considered with Fever > 7 days
Define intermittent vs spiking vs remittent vs sustained vs relapsing fever
Intermittent - temp returns to normal at least once a day
Spiking - high peak quick defervescence
Remittent - temp fluctuates but always remains elevated
Sustained - fevers are persistent with little fluctuation
Relapsing - temp returns to normal for most of the day and then fever returns
What are the most common causes of FUO?
Viral infection Followed by: UTI Osteo CNS infections
What proportion of FUO go undiagnosed?
25% - undiagnosed or spontaneous resolution
Differentiate fever and hyperthermia?
Fever - caused by a rise in the hypothalamic set point
Hyperthermia - thermoregulatory system is dysfunctional or overwhelmed by a variety of internal/external factors
- excessive heat production (exertional heat stroke, thyrotoxicosis, cocaine intoxication)
- disorders of diminished heat dissipation (classic heat stroke, severe dehydration, autonomic dysfunction)
- disorders of hypothalamic dysfunction (cerebrovascular accidents, trauma)
How to decrease body temp in children with heat stroke?
Aggressive attempts at cooling
- Ice packs
- Fanning
- Ice water immersions
- Cool IV fluids
Until core temp < 39C
Avoid antipyretics and alcohol sponge baths
ABCs - supportive care - intubation, IV rehydration, pressors
