Kid Fevers:

1
Kid Fevers
A Hot Topic

• Lou Romig MD, FAAP, FACEP
• Miami Childrens Hospital

2
Fever in Kids
Some Hate it Hot

• Lou Romig MD, FAAP, FACEP
• Miami Childrens Hospital

3

• Fever
• Mythology

4
Fever Phobia!
5
Hot Topics

• What is fever?
• Facts and fallacies about fever
• Febrile seizures
• How and why to treat kids with fever

6
What is fever?

• Fever is a neurochemical response common to many
  animals
• Controlled in the human hypothalamus and mediated
  by numerous endogenous and exogenous chemicals

7
What is fever?

• Nerves in the hypothalamus maintain a normal set
  point temperature, usually in a range around 37C
  (98.6F)
• Set point varies in a circadian rhythm with
  lowest at around 4am and highest between 4-8pm

8
What is fever?

• Endogenous pyrogens can cause
• ?body temp
• sleepiness
• ?appetite
• Increased immune response

9

• What
• about
• the
• numbers?

10
Whats normal?

• Most common definitions are based on a study by
  Wunderlich in 1868
• Normal 37C (98.6F)
• Upper limit of normal 38C (100.4F)
• Weaknesses thermometry used, use of axillary
  temps

11
Whats normal?

• Mackowiak and Wasserman 1992
• 700 oral temps in 148 healthy young adult
  subjects
• Individual variation precludes the assignment of
  any single temperature as the normal.
• Range 35.6(96.0) 38.2(100.8)

12
Whats normal?

• There is no substantiation to the belief that the
  elderly have lower body temps normally
• A higher normal range of temp in children has not
  been documented in the research

13
Whats fever?

• Mackowiak and Wasserman
• Any oral temp gt37.2C (98.9F) in the early morning
• Any oral temp gt37.8C (100F) at any time

14
Thermometry

• Gold standards are rectal for children and oral
  for older children and adults
• Axillary temps are not reliable and may vary as
  much as 1C from rectal
• There is no reliable conversion factor for
  axillary vs rectal temps

15
Thermometry

• Tympanic thermometry is not accurate and may be
  technique-dependent
• Infrared temporal artery (TA) thermometry is only
  slightly better than tympanic thermometry
• TA temps are consistently lower than rectal temps
  but there is no reliable conversion factor

16
How hot is high?
17
How hot is high?

• Dubois, 1949
• Human upper limit of fever 41 42C
  (105.8-107.6F)
• Almost never exceeds 42C unless theres a failure
  in thermoregulation

18
How hot is high?

• McCarty and Dolan, 1976
• 40C (104F) may be the upper limit of fever in
  infants lt12 weeks old
• Remember that young infants can have infections
  with normal or lowered body temps

19
Danger!?
Fever Mythology
20
Fever can cause damage
21
Why the concern?

• Seizures and complications
• Brain damage because of the infection causing the
  fever (meningitis or encephalitis)

22
Fact or fiction?

• No human studies published
• Animal studies suggest that a body temp of gt42C
  (107.6F) in humans may trigger enough adverse
  effects on a cellular level to cause death

23
Fact or fiction?

• Animal studies
• Tgt 105 may cause respiratory alkalosis and
  occasional electrolyte imbalances
• T gt 105.8 may cause cellular swelling and damage
  in the brain, kidneys and liver

24

• An infection is more dangerous if it gives a high
  fever or if the fever doesnt come down with
  treatment

25
Hi temp bad infection?

• No studies have conclusively proven any
  correlation between height of temperature and
  outcome of an infection or disease outcome.

26
Hi temp bad infection?

• Several studies suggest that children with
  temperatures greater than 41C (105.8F) have a
  greater chance of having a serious bacterial
  illness.

27
Hi temp bad infection?

• Several studies suggest that fever of 40C (104
  F) signals increased risk of serious bacterial
  illness for infants from birth to three months of
  age.

28
Poor response to tx bad?

• Failure of antipyretics to control fever has not
  been proven to correspond with severity of
  illness.
• Improved general appearance after antipyretics
  may indicate a less severe illness.

29
Cover up if you have chills!
30
Whats cookin with chills?

• Chills are evidence of the hypothalamus causing
  the body to generate heat to reach the altered
  set-point.
• Covering up will only keep in the heat.

31
Dont give milk to babies with fever!
32
Febrile Seizures
33
Doin the fever flop
34
Characteristics of F.S.

• Incidence of 2-5 in US
• 6 mo 3 yrs, median 18-22 mo
• Boys more often than girls
• Often occurs with the first fever of an illness

35
Characteristics of F.S.

• 85 of all F.S. last for lt15 min and dont recur
  within 24 hrs
• 50 have temp between 39-40C
• 25 have temp gt 40C

36
Characteristics of F.S.

• 1/3 will have recurrence of F.S.
• The younger the age at 1st F.S., the higher the
  incidence of recurrence
• El-Radhi, 1998
• Presenting temp lt39 for 1st F.S. have 2.5x risk
  for recurrence within the same illness and 3x
  risk for recurrence with other illnesses

37
Characteristics of F.S.

• Simple F.S. are generalized tonic-clonic with
  brief post-ictal period
• Complex or atypical F.S. can be focal, atonic, or
  prolonged

38
Its in the genes

• Multiple studies have shown several genetic loci
  that code for susceptibility to febrile seizures
  

39
Fever Sz ? Febrile Seizure

• Meningitis/Sepsis
• Seizure disorder
• Medication/Poison-induced

Febrile seizure is NOT an EMS diagnosis
40
Febrile SeizuresFact or Fiction
41
F.S. are caused by the rate of rise of temp

• Berg, 1993 failed to prove the rate of rise
  theory
• Bottom line we dont know what causes F.S.!

42
F.S. cause brain damage

• No studies have demonstrated that febrile
  seizures without complicating hypoxia cause brain
  damage
• One study suggests that recurrent F.S. may result
  in decreased IQ

43
F.S. can cause epilepsy

• Risk factors for afebrile sz
• Complex 1st F.S.
• Abnormal neuro state before 1st F.S.
• Afebrile sz history in parents or siblings
• If gt2 risk factors, 10 chance of developing
  epilepsy

44
Treating the fever can prevent F.S.

• Canfield, 1980 Knudson, 1991 van Stuijvenberg,
  1998
• Antipyretics are not protective
• Rectal/oral diazepam at time of fever is
  protective
• Daily oral phenobarbital is protective but has
  undesirable side effects

45
Treating the fever can prevent F.S.

• There is no evidence that bringing the fever down
  by any means will stop or prevent a febrile
  seizure.

46
The Bottom Line for F.S.

• Theyre more scary than dangerous
• Most resolve without anticonvulsant treatment
• Antipyretic treatment does not prevent or treat
  F.S.
• Not all seizures with fever are febrile seizures

47
Fever Treatment
48
Antipyretics

• There is no evidence to support one antipyretic
  over another when considering effectiveness
• No delivery route (po/pr) is more effective than
  another

49
Antipyretics

• Several studies have shown that many parents
• Dont even attempt to treat fever before seeking
  medical evaluation
• Dont give correct antipyretic doses

50
Antipyretics

• Acetaminophen (APAP) 10-15 mg/kg po/pr q4h
• There is no difference in effectiveness based on
  po or pr routes
• There is no increased effectiveness when pr dose
  of APAP is increased to 45mg/kg
• Ibuprofen 10mg/kg po q6-8h

51
APAP vs Ibuprofen

• There is no significant benefit to using either
  antipyretic preferentially
• There is no benefit in alternating the two meds
  but there is a significantly increased chance of
  dosing error and possible overdose

52
Cooling methods

• Never use ice, cold water or alcohol
• Use tepid water or cool compresses over head and
  pulse points

53

• Beware
• of chills if using external cooling

54
Should we even treat fever?

• Animal studies suggest that the fever mechanism
  is a positive adaptive response
• Triggers host immune responses
• May stabilize cell membranes

55
(Why) should we treat fever?
56
Reasons to treat fever

• Increased metabolic stress and oxygen demand
• Patients with poor cardiac reserve
• Patients with poor pulmonary reserve
• Lowering the seizure threshold

57
Reasons to treat fever

• Patient comfort
• Parent comfort

58
Should EMS providers be treating fever?
59
Pros

• Providing an additional service to our customers
• Comfort measure

60
Cons

• Treat and release?
• Documentation of fever
• Dosing of meds
• Reinforcement of fears

61
Summary

• Fever is not the clearly defined concept many
  believe it to be.
• Both the lay public and the medical community
  need more education about fever.
• Fever Phobia is unfounded.
• Fever treatment by EMS personnel is
  controversial.