Fever

Question 1

What is the Sn and Sp of tactile detection of a fever?

Answer 1

Sn 75-89%
Sp 56-85%

PPV 57-63%
Why its important to confirm with a recorded temp
Rectal in infants

Question 2

When does the variation in body temp match the circadian rhythm?

Answer 2

2 years

Peak in the evening (1700-1900)
Trough in the early AM (0200-0600)

Question 3

How is fever produced by the body?

Answer 3

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

Question 4

Does bundling cause fever in infants?

Answer 4

It can

Do a 30-60 min period body equilibrium (unbundle) and then recheck the temp

Question 5

Does teething cause fever?

Answer 5

Can cause mild temperature elevation

But teething has not be shown to be associated with temps > 38.5C

Question 6

Is sponging effective to reduce a fever?

Answer 6

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

Question 7

Name 4 fever myths

Answer 7

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

Question 8

What are the normal increase in HR and RR with each degree rise in temp?

Answer 8

10-15 bpm (HR) and 3-5 breaths/min (RR) for each degree rise in temp

Question 9

Name 2 RF for fever being indicative of more serious illness

Answer 9

Young age (<2 months)
Immunocompromised (diseases or meds)

Question 10

Name 3 reasons we are more concerned with fever in young infants?

Answer 10

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

Question 11

Name the 4 most common organisms for infection in febrile infants (< 1 month)

Answer 11

GBS
E coli
Listeria
Staph Aureus

GELS or LEGS
Maternally acquired bugs

Question 12

Name the 4 most common organisms for infection in febrile infants (> 6 weeks)

Answer 12

Strep Pneumococcus
H flu
Influenza
Neiserria Meningococcus

SHIN

Community acquired bugs

Question 13

Name the 4 most common organisms for infection in febrile infants (4-6 weeks)

Answer 13

Both maternally and community aquired bugs
LEGS SHIN

Listeria
E coli
GBS
Staph Aureus

Strep pneumo
H flu
Influenza
Neiserria Meningococcus

Question 14

List 3 sets of low-risk criteria for febrile infants?

Answer 14

Boston
Philadelphia
Rochester

Question 15

Name the specific parameters for each set of low-risk criteria

Answer 15

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

Question 16

What are the Sn and NPV for each criteria

Answer 16

Boston - Sn unknown NPV 94.6%
Philadelphia - Sn 100 NPV 100
Rochester - Sn 92.4 NPV 98.9

Question 17

What is a FSWU?

Answer 17

CBC
UA
LP

Cx - blood, urine, CSF

Question 18

What is the most common type of bacterial infection in infants < 2 months?

Answer 18

UTI

Question 19

What is occult bacteremia?

Answer 19

Unsuspected bacteria in the blood

Well appearing child, no focus, bacteria in the blood

Question 20

Are WBC and CRP good predictors of serious infection?

Answer 20

No

Procalcitonin is better

Question 21

What bug are you worried about when you see a petechial rash?

Answer 21

N meningiditis

Petechial rash makes you think of a more serious invasive bacterial infection

Other possibilities:
S. pneumococcus
GAS
S. aureus
E. coli
Rickettsia

Question 22

What is the definition of fever without an origin/unknown origin (FUO)?

Answer 22

Fever with no focus x 3 or more weeks

Sometimes can be considered with Fever > 7 days

Question 23

Define intermittent vs spiking vs remittent vs sustained vs relapsing fever

Answer 23

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

Question 24

What are the most common causes of FUO?

Answer 24

Viral infection
Followed by:
UTI
Osteo
CNS infections

Question 25

What proportion of FUO go undiagnosed?

Answer 25

25% - undiagnosed or spontaneous resolution

Question 26

Differentiate fever and hyperthermia?

Answer 26

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)

Question 27

How to decrease body temp in children with heat stroke?

Answer 27

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