Fever. Zager. Katelyn Rogers. 03.24.10.
Case 1
You are volunteering in the tent for Grandma’s Marathon and the
first wave of runners are finishing. The first patient of the day is
a 27-year-old male (5th place finisher) who is ashen, mumbling,
and stumbles in supported by two friends. His vital signs are
taken. Pulse= 168, RR= 42, pulse ox= 85%, BP= 85/ 54,
Temp=107.2 degrees. Hyperthermia due to dehydration &
muscle overactivity.
Case 2
You are working in the emergency room and go on to see the
next patient- a 20-month-old female with three days of elevated
temps at home. Parents measured a temperature of 104.6
degrees and have brought her in at 11 PM. She has no URI
symptoms, no rash, but has had some vomiting today. Her vital
signs are taken. Pulse= 168, RR= 42, pulse ox= 98%, BP=
85/54, Temp= 105.4 degrees.
Normal HR for her not in fever (70-80). RR would be a little lower.
Fever, bc this is fairly normal for her physiologically. A urine sample should be
taken, she has a UTI.
To treat (fever)….or not to treat….that is the question! T of
102 or 105 degrees probably won’t change the tx, so really not
impt to know amt and the method they are using to measure it.
Many parents believe that fever is injurious. This table
measures parent beliefs around harmful causes of fever:
Some inflammatory focus triggers fever. Effects will cause muscle shivering
(can inc heat production to 20x) and then vasomotor efferents squeeze down
to reduce T loss. Cold and blue (not cyanotic bc centrally nice & pink). Fevers
will cycle with kids.
Physiologic Responses to Increase Body Temperature (Heat
Production/ Reduce Loss):
Peripheral vasoconstriction
Shivering
Behavioral (seeking clothing, blankets, warmth)
(Accompanied by tachycardia and tachypnea)
Physiologic Responses to Reduce Body Temperature (Heat
Loss):
Sweating
Peripheral vasodilation
Physicians May Suffer From the Same Contextual Problems
As Parents:
May and Bauchner ((1992) performed a survey of Pediatricians
and found:
-65% believed that fever alone could cause bodily injury
-60% cited a temperature above 40 degrees (C) as a
critical point
-21% listed brain damage as the most serious
complication of fever
-26% listed death as the most serious complication
Reasons Not to Treat Fever:
Fever enhances immune function
Fever is physiologic
Limited research suggests that it may shorten duration of illness
Reasons to Treat Fever:
Comfort
??? Metabolic preservation in certain chronic disease (i.e.,
cardiac)
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Effective Treatments for Fever Reduction:
Acetaminophen (15 mg/kg/dose q 4 hours up to standard adult
dosage)
Ibuprofen (10 mg/kg/dose q 6 hours up to standard adult
dosage)- risk for nephrotoxicity if dehydrated.
Aspirin (not recommended under age 16)
All act on hypothalamus and PG cyclooxygenase cycle.
Ineffective Treatments for Fever Reduction:
Sponging
Bathing
Electric fans
Alternating acetaminophen/ ibuprofen (no more effective than
one agent)- also can get confused with dosing timesoverdose.
Causes of Fever:
-Infectious: viral, bacterial, fungal, and parasitic
-Inflammatory: Kawasaki Syndrome (vasculitis, age 3-9yo, w/ 5d
unremitting fever, no response to Tylenol or Ibuprofen, achy
joints, rash, etc), Juvenile Rheumatoid Arthritis
-Cancer: Acute Lymphocytic Leukemia
-Pharmacologic: Aspirin overdose
-(fictitious)
Considerations in Evaluating Febrile Children
-Pattern of fever reported by parents (reliable?)
-Age of Child (newborn to age 3 months more at risk for occult
bacteremia)
-Risk factors by age, chronic disease, immunization status,
travel, etc.
-Known patterns of disease entities- i.e., Kawasaki Syndrome
(think this if 5-6d out and still not responding to meds).
-Exam findings: vital signs, “sick appearance”, focal
abnormalities
Occult Bacteremia: Bacteria Recovered From Blood of
Nonseptic Individual
-More common in children under 3 than older ages
-Generally: pneumococcus, Hemophilus, meningococcus
-Vaccines licensed for all 3 typical bacterial pathogens (above)
-Less than 3% of febrile children under age 3 with temp > 103
ESR and CRP:
-CRP> 4.0 suggest increased chance of bacterial disease
-CRP> 10 have been associated with 85% chance of bacterial
infection
-ESR is an indirect measure of plasma acute phase reactants
-ESR can be affected by fibrinogen, RBC morphology, sex
-ESR fluctuates at a slower pace than CRP
Fever Under the Age of 30 Days: (“Throw the whole toolbox at them”)
-one study of 254 neonates presenting to an urban ER with temp
>38 (C) identified 32 infants with serious bacterial illness (SBI)
-No screening protocols for identifying young infants at “low risk”
have been validated.
-Evaluation must be individualized and strong consideration must
be given to “full sepsis work up”- CXR, blood culture, urine
culture, CSF studies and empiric antibiotics
-Can see late onset group B strep.
Fever From 30- 90 Days of Age (Am. Coll. Of ER Physicians):
-Full exam (are they “well appearing”?)
-Screening CBC
-CXR in children with respiratory symptoms
-Screen all infants for UTI (UA and urine culture)
-Infants who have positive screening receive blood culture, CSF
studies, and empiric antibiotics.
Fever From 3 – 36 Months of Age Nigrovic, Et Al, (Clinical Pediatric Emergency Medicine- March 2004)
-Pre- 1987 causes of bacteremia- Hemophilus & Pneumococcus
-Hib vaccination eliminated Hemophilus (1987)
-Pneumococcal vaccination (Prevnar) is about 85-93% effective
at prevention of invasive pneumococcal disease
-Febrile children- <2.5% rate of pneumococcal bacteremia (80%
spontaneous resolution?)
-1998 to 2001 surveillance- 69% drop in invasive pneumococcal
disease
-“Well-appearing”, febrile child > 6 mos + hx 3 doses Prevnar=
no screening CBC, blood culture at Boston Children’s Hospital
Urinary Tract Infection Is More Common Than Bacteremia
-Equal male:female ratio under age 6 months
-Caucasian female under age 3 ys with T> 39 degrees= 16% UTI
-UTI in uncircumcised : circumcised male (under age 1)= 10:1
(Rare to see over the age of 6 mos)
-Diagnosis by culture of urine (Do catheterized!)
Interpretation of CBC:
-WBC> 15K predicts bacteremia with 80% sensitivity, 69%
specificity, and positive predictive value of 6%
-WBC< 5K with ANC (abs neut count) < 1500 is worrisome
-ANC > 10K gives sensitivity of 76%, specificity of 78% and
positive predictive value of 8%
-Thrombocytopenia is exceptionally worrisome development
-Thrombocytosis is a frequent consequence of inflammation after
10- 21 days
-Total Band Count: ANC > 0.16 highly predictive of neonatal
sepsis
(So difficult to interpret, used to diagnose fever, used to decide to use
antibiotics. Not good! When get a cbc first look at the platelets.)
If no vaccine need to do a broader workup.
Febrile Seizures
Occur in about 4% of children
6 mos of age to 6 years
Associated with temp > 38 degrees
Absence of CNS infection/ inflammation
Absence of systemic metabolic disturbance
Absent hx of prior afebrile seizure
Febrile Seizure Classification:
Simple: duration less than 15 minutes, nonfocal (>90%)
Complex: longer than 15 minutes, may have focal component,
post ictal paresis (more likely underlying disease, refer)
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Etiology of Febrile Seizures:
-Genetic susceptibility: several chromosomal loci have been
identified in various extended families
-Siblings and parents of children with febrile seizures show 410% rate of epilepsy
-10-20% of parents/ siblings will have a hx of febrile seizures
-MRI studies suggest hippocampal abnormality may have role
Differential Dx
Involuntary myoclonic release movements
Shivering
Metabolic disorder
Bacterial meningitis
Viral encephalitis
To be a seizure need LOC.
Diagnostic Evaluation:
-Conflicted opinion regarding necessity of examining CSF in
children < 12 mos
-Consider LP in questions of meningitis or if seizure occurs after
first day of fever
-Routine metabolic studies rarely yield etiology
-Neuroimaging and EEG should be considered in “complex”
variety
Treatment of Febrile Seizures:
-Supportive care
-If duration exceeds five minutes consider emergent
anticonvulsant Tx (IV lorazepam @ 0.05 to 0.1 mg/ kg)
-IV fosphenytoin (15-20 mg/ kg) can be used if refractory (IV
Phenobarbital works better)
-Diazepam rectal gel (0.5 mg/kg) if IV access unavailable
-Fever reduction is unlikely to be accomplished by “external”
means (sponging, bathing)- best to use acetaminophen or
ibuprofen
Last Word
-Fever as the sole manifestation of serious illness is unusual.
Urinary tract infection is the most common of these obscure
etiologies- generally in the preverbal child (under age 3). Hence,
of all potential lab studies in the hunt for isolated fever, a UA is
more productive than a CBC.
-Febrile seizures are not rare. All parents will go into “panic
mode” in the face of this dramatic event. The health
professional’s role is first to assess and treat the needs of the
child- and, second, to interpret this event for the parents.
Questions:
1. A 2 year-old girl comes into the ER with a temp of 104F and no
signs of URI. What is the test you should order?
2. Which of the following is not a physiologic response to increase
body temperature?
a. Peripheral vasodilation
b. Shivering
c. Behavioral
3. What are the reasons to treat fever?
4. What are effective treatments for fever reduction?
5. In what age group is occult bacteremia seen? What bugs are
generally there?
6. T/F. Occutl Bacteremia is more common than UTI.
7. What is the most common test ordered to evaluate for fever?
8. In which of the following age groups would you do a UA & Urine
culture?
a. <30d
b. 30-90ds
c. 3-6months
9. T/F. Febrile seizures in kids often have systemic metabolic
disturbances and are not concerning.
10. T/F. Continuous anticonvulsant therapy is recommended for
prevention of febrile seizures.
Recurrent Febrile Seizure Treatment
-Home use of rectal Diazepam gel can be used by parents if
seizure is longer than 5 minutes
-Focal seizures are more likely to be prolonged
Prevention of Febrile Seizures
-AAP does not recommend intermittent or continuous
anticonvulsant use (somnolence, etc)
-Evidence supporting aggressive antipyretic use likewise has no
evidence
Prognosis for Febrile Seizures
-Recurrence rate is 50-65% if 1st seizure occurs <12 months
-Recurrence rate is 20% in older children
-Majority of recurrences are within one year of the first seizure
-No evidence for developmental, neurologic, cognitive sequelae
-“Nl child” w/ simple febrile seizure=“slightly” incd risk epilepsy
-Risk factors for later epilepsy=focal sz, prolonged sz, multiple
sz< 24 hrs
-Impt to educate.
Next to Last Word
-30% of office visits to Peds have fever as the primary concern.
More than 50% of after hours phone calls involve fever concerns.
Fever is a significant factor in primary care of children.
-Fever is not a diagnosis (though, there is an ICD9 code for it)
but rather a sign of an underlying disorder. Fever by itself is not
harmful and there is increasing recognition of its role in
enhanced body response to infection.
Answers:
1. UA – best if catheterized!
2. A, rather is constriction.
3. Comfort & possibly metabolic preservation in certain chronic
diseases.
4. Acetominophen, Ibuprofen, & aspirine (>16 yo)
5. Under 3 yo. Penumococcus, Hemophilus, & Meningococcus.
6. F
7. CBC
8. ALL!!!! Even in the oldest group with a Hib & PCV7 vaccine you do
a UA & culture!
9. F. Febrile seizures in kids have an ABSENCE of systemic
metabolic disturbances and are not concerning.
10. F.
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