Transcript Fever Phobia”

“Fever Phobia”
Dawn S. Tuell, M.D.
Associate Professor of Pediatrics
Quillen College of Medicine
• I, Dawn Tuell, do not have a financial interest or
affiliation with one or more organizations that could be
perceived as a real or apparent conflict of interest in the
context of the subject of this presentation
Disclosure Statement of
Financial Interest
• I, Dawn Tuell, did not complete my slides by the deadline
to be included in your manual. The good news is your
manual will collect dust and eventually make it to the
recycle bin in the next year.
Confession Statement
•
•
•
•
•
Depends on who you ask…
Where you take it…
The type of thermometer used…
The time of day…
Age of the child…
What is a fever?
• An increase in the body’s temperature above normal
FEVER
• Range 97.2° (36.2°) – 99.5° (37.5°)
• Normal diurnal variation in temperature 0.5°C from the
mean
• Vary based on age, gender, physical activity, ambient air
temperature
• Vary with anatomic site
• Core body temperature is measured most accurately at the
pulmonary artery
• There is no single value for normal body temperature
What is a normal
temperature?
Which of the following
children have a fever?
20%
1.
2.
3.
4.
5.
20%
20%
2
3
20%
20%
3 year old with an axillary
temperature of 99°
An 18 month old with a pacifier
temperature of 99.8°
6 month old who felt hot last
night
9 month old with tympanic
temperature of 100°
None of the above
1
4
5
•
•
•
•
•
Rectal temp > 100.4°
Oral temp > 100°
Axillary temp > 99°
Tympanic > 100.4°
Forehead/temporal artery > 100.4°
AAP Definition
You should add a degree to an axillary
temperature to reflect core body
temperature
50%
50%
1. True
2. False
1
2
• Rectal temperatures are the gold standard for temperature
measurement
• Axillary temperatures are not as reliable as rectal and are
generally lower
• However “one degree rule” not appropriate due to
variability
• Literature shows axillary thermometers did pick up all
fevers
• No false positives with axillary temperature
Axillary vs. Rectal
•
•
•
•
Safe and comfortable for children older than 5 years
Less lag time
More accurate than axillary thermometers
Affected by temperature of recently consumed fluids or
mouth breathing
Oral Thermometers
• Quick, comfortable, cost effective
• Infrared ear thermometer does not accurately predict
rectal temperature
• Fails to diagnose fever in 3-4 out of every 10 febrile
children
• Difficulty in aiming thermometer at TM, especially in
infants younger than 2 months of age
• Home use thermometers may be less accurate than
clinical use thermometers
Tympanic Thermometer
•
•
•
•
•
Child “feels warm to the touch”
Subjective, can vary with environmental factors
Sensitivity by parents 71-89%
Specificity and positive predictive value <50%
More useful to exclude rather than confirm presence of a
fever
“Tactile” Temperature
• The way that works for you…
• Use a consistent form of measurement
• Make the measurement at the same site to monitor
changes in body temperature
What is the best way to
measure temperature?
What is a low grade
fever?
20%
1.
2.
3.
4.
5.
20%
20%
2
3
20%
20%
98.8°-99°
99°-100°
99°-101°
100°-102°
101°-103°
1
4
5
• 100° (37.8°)- 102° (39°)
Low grade fever
What is a high fever?
1. <100° (37.8°)
2. 100°-102° (37.9°38.9°)
3. 102.1°-104° (39°40°)
4. >104° (40°)
25%
1
25%
25%
2
3
25%
4
Parental definition of a high fever
Temperature at Which Pediatricians
Consider Infants to Have Mild, Moderate
and Serious Fever by Infant Age
• Temperature control lies in the thermoregulatory center of
the hypothalamus
• Complex set of cytokine-mediated responses and
production of acute phase reactants change hypothalamus
set point
• Body temperature elevates via heat generation and heat
conservation
• Pyrogens are substances that produce fever
• Cryogens limit temperature height during fever
Why Does My Child Have a
Fever?
The febrile response.
Avner J R Pediatrics in Review 2009;30:5-13
©2009 by American Academy of Pediatrics
How high a fever can go if left untreated.
Crocetti M et al. Pediatrics 2001;107:1241-1246
©2001 by American Academy of Pediatrics
Is Fever a Symptom or a
Disease?
50%
50%
1. Symptom
2. Disease
1
2
• Counsel parents on how to “control” a fever
• Order blood tests to evaluate fever
• 50% of HCPs report pressure to prescribe antibiotics for a
fever
• Parents perceive treatment of fever is antibiotics
Do we treat as a disease?
The height of the fever predicts
a more serious illness
50%
50%
1. True
2. False
1
2
• Pre-pneumococcal conjugate vaccine this was likely a
true statement
• Some studies show that hyperpyrexia (T>106/41.1) is
associated with a higher incidence of serious illness
• Clinical appearance rather than height of fever is a more
powerful predictor of serious illness
• Thorough H&P to guide decision matrix
Height of Fever
A response to antipyretic medication
lowers likelihood of serious bacterial
infection
50%
50%
1. True
2. False
1
2
• A response to antipyretic medication does not change the
likelihood of a child having serious bacterial infection
and should not be used for clinical decision making.
•
Temperature Response
•
Bacteremic
•
•
•
•
•
•
•
Nonbacteremic
Authors Year
Study Design
Antipyretic Agent
Age of Subjects, y
No.∗
T,† °C (°F) ↓T‡
No.∗
T,† °C (°F) ↓T‡
P§
Torrey et al22
1985
Prospective/observational Acetaminophen/aspirin
≤2
16
40.1 (104.2) 1.3
239
39.9 (103.8) 1.05
.14
Weisse et al23
1987
Prospective/observational Acetaminophen
≤17
11
NG
1.4
16
NG
1.2
.37
Baker et al24
1987
Prospective/observational Acetaminophen
≤6
10
40.1 (104.2) 1.5
225
39.6 (103.3) 1.0
NG
Mazur et al25
1989
Retrospective/case control Acetaminophen
≤6
34
39.8 (103.6) 1.0
68
39.8 (103.6) 1.5
<.001
Baker et al26
1989
Prospective/observational Acetaminophen
≤2
19
40.1 (104.2) 1.7
135
40.0 (104) 1.6
>.05
Yamamoto et al27
1987
Prospective/observational Acetaminophen
≤2
17
40.5 (104.9) 1.6
216
40.4 (104.7) 1.6
.85
Systematic Review of
Evidence
Which of the following is not a known
complication of fever associated with
infection?
20%
20%
20%
1. Cerebral damage
2. Increased
catabolism
3. Seizure
4. Tachycardia
5. Tachypnea
1
2
3
20%
4
20%
5
Type
Schmitt (n = 81)
Seizure
15%
Brain damage
45%
Death
8%
Dehydration
4%
Really sick
1%
Coma
4%
Delirium
12%
Blindness
3%
No response
6%
Other
–
14%
Total
100%
Crocetti et al (n= 340)*
32%
21%
14%
4%
2%
2%
1%
1%
9%
100%
Parental Report of Harmful
Effects of Seizures
•
•
•
•
•
Enhance leukocyte mobility and activity
Activates T lymphocytes
Stimulates production of interferon
Inhibit bacterial and viral function
Shortens duration of illness by creating an unfavorable
host environment
• Likely beneficial in children with normal host responses
Benefits of a Fever
• Increased metabolic demand
• Increased insensible fluid loss
• General discomfort
Disadvantages of a fever
• Fever is a normal physiologic response that results in increase
in hypothalamus set point
• Hyperthermia is rare response with failure of normal
homeostasis that results in heat production that exceeds
capability to dissipate heat
• Characteristics – hot, dry skin, CNS dysfunction, delirium,
convulsions, coma
• Should be addressed promptly
• Temperature above 41°-42°C can have adverse physiologic
effects
• Cannot extract hyperthermia data to apply to fever outcomes
Hyperthermia vs. Fever
• Most febrile illnesses last 3-5 days
• Treatment of febrile children without a source subject to
great debate
• Majority have benign, self-limited illness
• Serious bacterial illness can be difficult to diagnose and
has a high morbidity
Fever
A 3 week old term newborn presents
with a fever of 38°C. What should be
done next?
20%
1.
2.
3.
4.
5.
20%
20%
2
3
20%
20%
Draw a blood culture, CBC and
start oral antibiotics
Risk stratification approach based
on WBC count and appearance
Reassure and reassess tomorrow
Admit for cultures and IV
antibiotics
None of the above
1
4
5
• Febrile infant < 1 months of age immature immune
response
• Up to 10% of febrile infants have serious bacterial illness
• Not yet developed many clinical signs to judge clinical
appearance
• Most management strategies recommend routine
hospitalization and empiric antibiotics pending results of
blood, urine, and CSF cultures
Fever < 1 month
• Risk stratification using WBC, UA and often CSF to
determine need for hospitalization and empiric antibiotics
Fever 1-2 months
A 10 month old girl has a temperature of 102° (38.9 °) for 2 days. Her
parents deny any other symptoms except increase in fussiness.
Immunizations are UTD. Findings on PE are normal. Which test is most
helpful in establishing a diagnosis in this child?
20%
20%
20%
1. Blood culture
2. Chest radiograph
3. Complete blood
count
4. C-reactive protein
5. Urine culture
1
2
3
20%
4
20%
5
• Usually benign viral origin
• CBC, blood culture, urine culture – utility is diminshing
• With S. pneumo and Hib vaccines occult bacteremia
decreased from 3% to <0.7% in this vaccinated age group
• Occult UTI much more likely with a prevalence of 2.18.7% - highest in girls younger than 1 year
Fever 3-36 months
A previously healthy 12 month old has a
fever of 101.2° You would recommend
20%
1.
2.
3.
4.
5.
20%
20%
2
3
20%
20%
Alternate Ibuprofen and
Acetaminophen every 4 hours
Ibuprofen every 6-8 hours
Acetaminophen every 4-6 hours
Use antipyretic based on the
appearance of the child
Sponging or bathing with tepid
water
1
4
5
• Bathing with cold water should not be used as it leads to
vasoconstriction
• Rubbing alcohol can cause vasoconstriction and
absorption through the skin leading to toxicity
• Tepid bathing provides only marginal temperature
reduction but increases discomfort and shivering
Sponging
• Ibuprofen and Acetaminophen inhibit cyclo-oxygenase
which converts arachidonic acid to prostaglandin
• Interleukin mediated steps continue to increase the
hypothalamus set point
• Decreased prostaglandins work to override the
interleukins
• Lower hypothalamus set point only in the febrile state
Antipyretics
Caregiver's use of antipyretics.
Crocetti M et al. Pediatrics 2001;107:1241-1246
©2001 by American Academy of Pediatrics
• A child must maintain a “normal” temperature at all times
• ½ of parents consider a temperature of <38 (100.4) to be
a fever
• 25% of caregivers give antipyretics for temperature of
<37.8 (100.4)
• 85% parents report awakening their child from sleep to
give antipyretics
• Up to ½ administer incorrect doses of antipyretics
Parental Antipyretic
Practices
• Dose 10-15 mg/kg per dose q 4-6 hours
• Onset of antipyretic effect within 30-60 minutes
• Approximately 80% of children will experience a
decreased temperature
• Hepatotoxicity most commonly seen with acute overdose
• Concern with supratherapeutic doses and frequent
adminstration
Acetaminophen
Acetaminophen use has been
associated with the following:
1.
2.
3.
4.
5.
May suppress immune response
to rhinovirus
May be important risk factor for
development and/or maintenance
of asthma
Associated with
rhinoconjunctivitis symptoms
Associated with eczema
symptoms
All of the above
20%
1
20%
20%
2
3
20%
4
20%
5
•
•
•
•
•
•
Dose 5-10 mg/kg dose q 6-8 hours
Recommended for infants > 6 months
More effective antipyretic
Longer duration of antipyresis
Potential for gastritis
Concern for nephrotoxicity, especially in dehydration or
medically complex children
• Possible association between ibuprofen and varicellarelated invasive group A streptococcal disease
Ibuprofen
•
•
•
•
•
NOT recommended by AAP in 2011 Clinical Report
67% parents alternate antipyretics
50% pediatricians advocated this practice
No conclusive proof alternating is safe
May be more efficacious in reducing temperature in short
term, no long term difference
• Can be confusing to parents
• Potential for incorrect dosing and increased risk of toxicity
• Primary endpoint, reduce discomfort, not normalize
temperature
Combination Antipyretics
“Dump” the combo
antipyretic practice
A 18 month old had his first febrile
seizure last month, you would advise
parents
1.
2.
3.
4.
5.
Antipyretic therapy will reduce
recurrence of febrile seizures
Febrile seizures have excellent
long-term outcomes
The higher the fever, the more
likely a seizure will occur
Give antipyretics for 24 hours
after immunizations to prevent a
seizure
Go to the ER anytime a seizure
occurs
20%
1
20%
20%
2
3
20%
4
20%
5
• AAP Clinical Practice Guideline, 2008
• High rate of recurrence
• No greater risk for developmental delays, learning
disabilities, or seizures without fever
• Antipyretics ineffective in preventing recurrent febrile
seizures
• Regular vs. sporadic treatment does not influence
outcome of febrile seizures
Febrile Seizures
• A. Pretreatment with acetaminophen or ibuprofen prior to
immunizations to minimize discomfort and febrile
response
• B. Treatment with acetaminophen or ibuprofen after
immunizations to minimize febrile response
• C. Antipyretics are not routinely needed for
immunizations
A 12 month old has an appointment
for WCC and immunizations. You
routinely advise
A 12 month old has an appointment for
WCC and immunizations. You routinely
advise
1.
2.
3.
Pretreatment with acetaminophen
or ibuprofen prior to
immunizations to minimize
discomfort and febrile response
Treatment with acetaminophen or
ibuprofen after immunizations to
minimize febrile response
Antipyretics are not routinely
needed for immunizations
33%
1
33%
2
33%
3
• Recent study suggests possibility of decreased immune
response to vaccines in patients treated early with
antipyretics
• Goal in treating a fever: child’s comfort not normalization
of temperature
• Restore nutrients and water lost
• Proper hydration
• Comfortable environment
Fever Management
•
•
•
•
•
•
•
•
Fever is a normal response to infection
Fever is a symptom, not a disease
Fever determination doesn’t always need to be exact
Treat the child’s comfort rather than a specific
temperature
Fever will persist until disease process resolves
Clinical appearance is important
Use the term “fever therapy” instead of “fever control”
Safe storage of antipyretics
Parental Education