1. Mark Bromley PGY 2 Adam Oster FRCPC
Febrile Child
Mark Bromley PGY 2
Adam Oster FRCPC

2. Agenda 1. Pathophysiology (briefly) 2. Young Infants (1 – 3 months)
3. Neonates (Birth – 1 month)
4. 3 months – 3 years

3. What is Fever? An elevation of body temperature?
Fever is an ↑ temperature as part of a specific biological response, mediated and controlled by the CNS
Not heat stress
Not heat illness

4. NORMAL BODY TEMPERATURE
Varies over the course of the day (circadian rhythm)
Normal daily temperature variation is 0.5 ºC
↑ after an illness
Is controlled by the thermoregulatory center located in the anterior hypothalamus

5. (Pyrogens) Infectious agents / Toxins / Mediators of inflammation
Cellular sources: monocytes, neutrophils, lymphocytes
Many others, when stimulated
Infectious
Most exogenous pyrogenic substances are from
Bacterial
Fungal
Viruses
Induce pyrogenic cytokines by infecting cells
Non-Infectious
Inflammation
Trauma
Antigen-antibody complexes

6. (Antipyretics/ NSAIDs act here)
Infectious agents / Toxins / Mediators of inflammation (Pyrogens)
stimulate
Monocytes / Macrophages / Endothelial cells / Other cell types
release
Pyrogenic cytokines - IL- 1, TNF, IL- 6, IFNs
Anterior hypothalamus (Mediated by PGE2)
results in
Elevated thermoregulatory set point
leads to
Increased Heat conservation (Vasoconstriction/ behaviour changes) Increased Heat production (involuntary muscular contractions)
result in
F E V E R
(Antipyretics/ NSAIDs act here) 

7. Temperature Regulation
Heat Gain
Clothing
Behaviour
Muscle
Liver
HYPOTHALIMUS
Lungs
Skin
Heat Loss

8. Case 2 month ♂ HPI Baby looks good
Previously well
No meds
Vaccines are up to date
HPI
2 day history of fever
This AM he is more irritable & ↓PO intake
Rhinorrhea and non-productive cough
Baby looks good
…but you think you should probably check vitals
How would you like to check temp?

9. What is a fever Wunderlich Infants
1 million measurements in 25,000 patients
Determined the upper limit of normal
Infants
Rectal temp >38oC

10. What is a Fever Rectum: Gold Standard > 38oC to > 38.2oC
….depending on the study and local custom
Not influenced by ambient temperature and its use is not limited by age
It is frightening for small children and may be psychologically harmful for older children.
Discomfort and is painful for patients with peri-rectal infxn / irritation
Varies depending how deeply the thermometer is inserted into the rectum, local blood flow, and the presence of stool and diarrhoea
May lag behind a rapidly changing core temp
?poor blood flow to the rectum
In the presence of shock, perfusion of the bowel, including the rectum, may be markedly impaired, and RT will lag significantly behind changing core temp

11. What is a Fever TACTILE Axilla
Oldest and still the most widely used method of evaluating body temp
Inaccurate, mainly because of the lowering of skin temp during the early phase of fever
Operator dependent
Medical staff 42% accurate
Mothers 80% accurate
Axilla
Safe, easily accessible, and reasonably comfortable
requires supervision in case displacement occurs
takes longer than rectal or sublingual measurement (5min mercury 40–80s electronic)
inaccurate
Fever » vasoconstriction » skin temperature cooling as the core temperature rises
Sweating and evaporation cause the AT to be lower than the core body temperature
Rectal temperature and AT differed by up to 3°C and AT was occasionally very low
Bergeson PS, Steinfeld HJ. How dependable is palpation as screening method for fever. Clin Pediatr 1974;13:350–1
Banco L, Veltri D. Ability of mothers to subjectively assess the presence of fever in their children. Am J Dis Child 1984;138:976–8

12. What is a Fever Oral Tympanic ↑ during fever Benefits: Deficits:
generally 0.6 ºC lower than rectal temp b/c of mouth breathing
Tympanic
60% of total heat loss from the body occurs via radiation in the form of infrared heat rays
↑ during fever
As the tympanic membrane receives its blood supply from the carotid artery, its temperature may reflect that of blood flowing into the hypothalamus
A suitable detector without a probe contact can measure the infrared rays emitted by the tympanic membrane
Benefits:
Fast and easy to use
No risk of cross infection
Not influenced by environmental temp
Deficits:
Inaccurate in children < 3 years
Peterson-Smith A, Barbar N, Coody DK, et al. Comparison of aural infrared with traditional rectal temperatures in children from birth to age three years. J Pediatr 1994;125:83–5

13. What about this guy?

14. Subjects: Children < 2y presenting to an acute care site
Each child had 6 temps taken
Temporal: 3 by nursing + 2 by parents
Rectal: 1 by nursing
Results:
Good correlation
Conclusions:
Variability too high for infants < 3months
Max temp of 3 taken may be a useful screening measure

15. Design: Cross-sectional agreement emergency department study
Subjects: 327 children <24 months of age
Methods: Temp measured rectally & Temporally by a single nurse
Outcome Measures:
Temp cut-off to detect rectal fever ≥38.0°C and ≥ 38.3°C
Sensitivities of >=90% and >=95% was determined

17. Results:
The mean difference between the rectal minus TAPM was -0.19°C ± 0.66°C
The sensitivities of TAPM temperature of ≥37.7°C to detect rectal fever
≥ 38.0°C / 90% (95% confidence interval: 0.83; 0.94)
≥ 38.3°C / 97% (95% confidence interval: 0.92; 0.99)
Conclusions:
The TAPM thermometer cannot replace the rectal
TAPM temperature of <37.7°C can be safely used as a screen to exclude rectal fever ≥ 38.3°C in infants 3 to 24 months

18. What do we do at the ACH?
Under 3 months rectal
Temporal for the rest

19. Case Continued Vitals: 125 25 80/46 37.8oC What do you want to do?
Are you worried?
Is this kid hiding bacteria?
Does Mom’s tactile fever count?

20. N=292 infants
Age < 2 months with a Hx of fever who were admitted for possible sepsis
Among the 19 infants with serious bacterial infection, all exhibited abnormal clinical and/or laboratory features on evaluation that were suggestive of underlying serious infection
224 (92 %) had fever on presentation or within 48 h of hospitalization
22 of 48 infants (46 %) with reported tactile fever had fever on presentation or within 48 hours of hospitalization
Of 26 infants with tactile fever who were afebrile on presentation, none had subsequent fever during hospitalization, and one had a serious bacterial infection (UTI)
Of 40 infants with reported fever per rectum who were afebrile on presentation, eight (20 %) had subsequent fever during hospitalization, and four (10 %) had serious bacterial infection

21. 30 days - 3 months

22. Case 2 month male Sniffles and loosening stools x 2days ↓feeding
PMHx: previously well
Birth history
SVD at term
Maternal GBS status negative
No maternal history of STI
Unremarkable nursery course

23. What is your approach?
Is this a low risk kind of baby?
…high risk kind of baby

24. HISTORY Associated symptoms (resp, GI)
Behaviors (feeding, irritability, activity)
Sick contacts (siblings, babysitters, day care)
Previous illness, or antibiotics
Birth history
maternal fever,
maternal group B streptococcus status (prophylaxis)
maternal history of STI (HSV, gonorrhea & chlamydia)
PROM
the infant's nursery course

25. Relying solely on clinical exam results in missed SBIs in this age group
Lab testing is required

26. We are looking for the high risk children …ideally a rule with
Great sensitivity
Good specificity
Excellent for those of us with limited clinical experience

27. Boston (Low Risk) Criteria
Fever ≥ 38.0 oC
HISTORY
29-89 days old
≥ 37 weeks gestation
Infant was previously well
Infant was well appearing
(no soft tissue / ear / bone infections)
LAB
WBC ≤ 20/uL
Urinalysis < 10 WBC/hpf (No Bacteria)
CSF ≤ 10 WBC/mm3
Stool < 5 WBC/hpf
CXR – Normal
When Obtained

28. Boston Criteria Low Risk Results: Conclusions: Ceftriaxone 50mg/kg
Discharged with follow-up
Results:
27 patients (5.4%) had a SBI
9 (1.8%) had bacteremia
8 (1.6%) had urinary tract infections w/o bacteremia
10 (2.0%) had bacterial gastroenteritis w/o bacteremia
476 (94.6%) did not
Conclusions:
Of the 27 infants with SBIs Clinical screening criteria did not enable discrimination between infants with and without SBI
All infants with SBI received an appropriate course of ABx and were well at follow-up
One infant had osteomyelitis diagnosed 1 week after entry into the study, received an appropriate course of IV ABx, and recovered fully
Outpatient treatment of febrile infants 28 to 89 days of age with intramuscular administration of ceftriaxone Pages Marc N. Baskin, Edward J. O'Rourke and Gary R. Fleisher

29. hilidelphia (Low Risk) Criteria
Fever ≥ 38.2 oC
HISTORY
29-56 days old
≥ 37 weeks gestation
Infant was previously well
Infant was well appearing
(no soft tissue / ear / bone infections)
LAB
WBC ≤ 15/uL (band:neutrophil ≤ 0.2)
Urinalysis < 10 WBC/hpf (No Bacteria)
CSF ≤ 8 WBC/mm3
CXR – Normal
Stool < 5 WBC/hpf & no blood
When Obtained

30. hilidelphia Criteria Low Risk Results: Conclusions:
Discharged with follow-up
Results:
N=422
43 patients (10%) had a SBI – all were “High Risk”
Low Risk: 101 – no SBIs
Conclusions:
Of the 27 infants with SBIs Clinical screening criteria did not enable discrimination between infants with and without SBI
All infants with SBI received an appropriate course of ABx and were well at follow-up
One infant had osteomyelitis diagnosed 1 week after entry into the study, received an appropriate course of IV ABx, and recovered fully
Byington CL, Rittichier KK, Bassett KE, et al. Serious bacterial infections in febrile infants younger than 90 days of age: the importance of ampicillin-resistant pathogens. Pediatrics 2003;111(5 Pt 1):964–8.

31. Rochester (Low Risk) Criteria
Fever ≥ 38.0 oC
HISTORY
< 60 days old
≥ 37 weeks gestation
Infant was previously well
Infant was well appearing
(no soft tissue / ear / bone infections)
LAB
WBC 5–15/uL
Urinalysis < 10 WBC/hpf (No Bacteria)
Stool < 5 WBC/hpf
CXR
When Obtained

32. High Risk: Hospitalized + Emperic Abx
Low Risk: Sent Home
(reasonable follow-up)

33. Neonatal fever: utility of the Rochester criteria in determining low risk for serious bacterial infections
Design: retrospective study
Population: 134 patients younger than 29 days
…fever without a source evaluated in the ED
Results:
Employing the Rochester criteria to the fully cultured neonates who could be risk-stratified, the sensitivity 86.4%
specificity 46.4%
positive predictive value 26.8%
negative predictive value 93.8%
Although outpatient management of febrile neonates may be feasible, a small percentage of neonates meeting low-risk criteria will have a SBI.
Neonatal fever: utility of the Rochester criteria in determining low risk for serious bacterial infections. Ferrera PC; Bartfield JM; Snyder HS Am J Emerg Med 1997 May;15(3):

34. Approach

35. Low Risk High Risk Term Well Appearance No Focus of Infxn WBC < 15
Urinalysis<10/hpf
CXR – no infiltrate
Stool – no blood
few WBCs
Age < 28d*
Look Toxic
Fail Criteria
When Obtained
*Ferrera PC et al Neonatal fever: utility of the Rochester criteria in determining low risk for serious bacterial infections. Am J Emerg Med.
1997;15:
*Kadish et al. Applying outpatient protocols in febrile infants 1-28 days of age: can the threshold be lowered? Clin Pediatr. 2000;39:81-88
*Baker MD, Bell LM. Unpredictability of serious bacterial illness in febrile infants from birth to 1 month of age. Arch Pediatr Adolesc Med.
1999;153:

36. High risk management? Full septic work up Hospital admission
Empiric antibiotics
CSF clear : 24h ceftriaxone
CSF pleocytosis: 48h Amp/Ceftriaxone …consider Vancomycin
Urine positive: Amp/Gent (cultures)

37. Low risk management A) Blood/urine/CSF cultures Ceftriaxone IM
single dose
Re-evaluation in 24h B)
Urine culture
No abx therapy
Careful observation

38. Lumbar Puncture Boston/Phily Criteria require it Rochester does not
Bacterial meningitis is rare (4.1/1000)
PE and peripheral WBC are unreliable
∴ strongly consider LP
?Antibiotics

39. Management of febrile (38ºC) healthy infant 28-90 days without source

40. Case 20 day male PMHx HPI Mother took a temp at 38.2oC
SVD at term
GBS negative Mom
Apgars 9/9
Discharged at 24 hours
HPI
Mother took a temp at 38.2oC
He has been feeding well with good weight gain
Not irritable or lethargic

41. In the ED
38.3oC /
Looks well / active / bright
Normal tone
Are you worried?
What would you like to do?

42. Birth – 30 days

43. Issues in the 0-30 day old Immature immune system
Improves steadily in the first three months of life
The immunologic task switches at birth from this coexistent state (graft preservation) to protection from invading pathogens
Neonates are more susceptible to SBI than older infants

44. Issues in the 0-30 day old Exposure to pathogens in the birth canal
Do not exhibit classic signs of sepsis
May deteriorate quickly
May not be able to mount a fever
++ with prems

45. Etiology Viral (most common)* Bacterial* ~12% Vertical Transmission
HSV
Varicella
Enterovirus
Influenza
Adenovirus
RSV
Bacterial* ~12%
Maternal Flora
GBS
Gram negative organisms ( E Coli)
Listeria
Strep Pneumo
H. Influenza
Vertical Transmission
Family
Hospital workers
↑ Prevalence with Age
*Baskin, MN. The prevalence of serious bacterial infections by age in febrile infants during the first 3 months of life. Pediatr Ann 1993; 22:462.
*Baker, MD, Bell, LM. Unpredictability of serious bacterial illness in febrile infants from birth to 1 month of age. Arch Pediatr Adolesc Med 1999;153:508.

46. Sources of (SBI) Infection
Infants ages 29 to 56 days who presented to an ED with rectal temperatures ≥38.2ºC
Baker, MD, Bell, LM, Avner, JR. Outpatient management without antibiotics of fever in selected infants. N Engl J Med 1993; 329:1437.

47. The young febrile infant may demonstrate few, if any, interpretable clues to the underlying illness

48. Infants between 1 and 28 days old with a fever should be presumed to have a serious bacterial infection (Level A)

49. Case 8 day ♀ Presents with fevers, irritability and poor feeding PMHx:
SVD at term
No Maternal Risk Factors
PE: No obvious source
CBC: WBC 8.6
…The nurse asks “do we really need to do the LP? What are the chances of meningitis with a normal WBC?”

50. [Ann Emerg Med. 2003;41: ]
Methods: logistic regression modeling and receiver operating characteristic curve analysis of peripheral blood WBC count and cerebrospinal fluid WBC count
Subjects: 3-89 day-old infants undergoing a sepsis evaluation
Results: 22 of 5,353 infants had bacterial meningitis
For diagnosing acute bacterial meningitis, the peripheral blood WBC count was poorly discriminating and significantly inferior to the cerebrospinal fluid WBC count
When relying on single and interval-based high-risk thresholds of peripheral blood WBC counts alone, the majority of infants with acute bacterial meningitis would have been missed.
Conclusion: Decisions to perform or withhold lumbar puncture should not be based on prevailing interpretations of the total peripheral blood WBC counts to maximize detection of bacterial meningitis in young infants

51. Peripheral WBC
…not sufficient to differentiate between patients with SBIs and those who do not*
∴ Cultures should be ordered on everyone
*Bonsu BK, Harper MB. A low peripheral blood white blood cell count in infants younger than 90 days increases the odds of acute bacterial meningitis relative to bacteremia. Acad Emerg Med 2004;11(12):1297–301.
Bonsu BK, Harper MB. Identifying febrile young infants with bacteremia: is the peripheral white blood cell count an accurate screen? Ann Emerg Med 2003;42(2):216–25.

52. UTI Testing Various rapid tests None detect ALL UTIs*
Urinalysis
Urine dipstick
Enhanced urinalysis
None detect ALL UTIs*
∴ urine cultures should be ordered
Urine bags are associated with high rates of contamination
*GorelickMH,Shaw KN. Screening tests for urinary tract infection in children: a meta-analysis. Pediatrics 1999;104(5):e54.
Shaw KN, McGowan KL, Gorelick MH, et al. Screening for urinary tract infection in infants in the emergency department: which test is best? Pediatrics 1998;101(6):e1.

53. Recommendations Rectal temperature 38ºC
blood, urine, and CSF cultures
regardless of clinical appearance
CXR if signs of Resp dz
Admit to hospital and treat with Abx
Amp/Gent or Amp/Cefotaxime
Acyclovir
(vesicles, seizures, CSF pleocytosis, ↑ liver transaminases)
Culture first

54. Case 2 wk ♂ presents with runny nose and sneezing
↓Feeding ↑Irritability
Sick contacts – 2yr brother has a snotty nose
PMHx unremarkable
38oC /37 30
OE: Expiratory wheezes
Rapid antigen test: (+) RSV
We’ve found our source!
…no need to poke him, right?

55. Management Full septic work-up Admission IV Abx CBC with Diff
Blood culture
Urinalysis & culture LP
If diarrhea present
Stool culture
fecal leukocyte count
If resp Sx present
CXR
Admission
IV Abx

56. Antibiotics Pathogens: Antibiotics First few weeks Rarely Community
GBS
E. coli
Listeria Monocytogenes
Community
Strep Pneumo
H flu
Neisseria Meningitidis
Antibiotics
Ampicillin
3rd generation cephalosporin
+/- Acyclovir
…Ceftriaxone?
Rarely
Staph aureus
Salmonella
Ceftriaxone not recommended in this age group as it displaces bilirubin from its albumin binding site

57. Question
What is the risk of SBI in neonates with an identified viral source?

58. Methods: 3-year multicenter, prospective, cross-sectional study
Determined RSV status by antigen testing of nasopharyngeal secretions
Evaluated infants with blood, urine, cerebrospinal fluid, and stool cultures
Subjects: N=1248 Febrile infants who were < 60 days
Results. The overall rate of SBIs was 11.4%
The rate of SBIs
RSV-positive infants 7.0% (17 of 244; 95% CI: 4.1%-10.9%)
RSV-negative infants 12.5% (116 of 925; 95% CI: 10.5%-14.8%)
The rate of UTI
RSV-positive infants 5.4% (14 of 261; 95% CI: 3.0%-8.8%)
RSV-negative infants 10.1% (98 of 966; 95% Ch 8.3%-12.2%)
The rate of Bacteremia
RSV-positive infants 1.1%
RSV-negative infants 2.3%
No RSV-positive infant had bacterial meningitis
Conclusions. The rate of SBIs is significant in febrile RSV(+) infants is significant

60. 3 months -3 years

61. Issues in the 3 month – 3 year olds
History is often helpful
Patients are more communicative
Well appearance does not exclude bacteremia but it is more closely correlated
Toxic 92% SBI
Ill 26% SBI
Well 3% SBI

62. Issues in the 3 month – 3 year olds
↑temp = ↑ risk of SBI / occult bacteremia
In this age group 39oC is often used as a threshold for investigation

63. History Immunization status Exposures to known infectious agents
Specifically PCV7
↓Risk of Invasive Pneumococcal Disease
Exposures to known infectious agents
Sx of focal infections
Ear Pulling
Cough
Vomiting
Bloody Stool
Crying with voids

64. Physical Exam Abnormal vital signs (including pulse ox)
Toxic appearance
(irritable, inconsolable, ↓perfusion, ↓tone, ↓activity, lethargy)
Localized infection
(omphalitis, joint/skin swelling or mm lesions c/w HSV)
Bacterial meningitis
(∆ sleep, ↓PO intake, ↑↓thermia, paradoxic irritability)
Bulging fontanel – late sign
↑ localization to CNS with age
Nuchal rigidity is present in only
0-6 months - 27% of patients
> 19 months % of patients
Bacterial Meningitis

65. Labs CBC and differential Urinalysis – culture Chest X-Ray
Boys <6mths
Girls <2yrs
Chest X-Ray
(RR>50, rales, rhonchi, retractions, wheeze, grunt, stridor, nasal flaring, cough)
Stool for leukocytes
(if diarrhea)
CXR: All 361 infants who had no clinical evidence of pulmonary disease had normal chest radiographs
85 of 256 infants (33 percent) with at least one of these signs had an abnormal chest radiograph.

66. PREVNAR (PCV7)
Pneumococcal conjugate vaccine …Streptococcus pneumoniae
Before universal immunization in the US
S. pneumoniae caused ~17,000 cases of invasive dz/year
700 cases of meningitis
200 deaths
the most frequent cause of bacteremia, pneumonia, meningitis, sinusitis, and acute otitis media
Since pneumococcal conjugate vaccine
the incidence of invasive pneumococcal disease has ↓ % in children < 2 years

67. Prevnar is a 7-valent vaccine (PCV-7)
It contains the cell membrane sugars of seven serotypes of pneumococcus, conjugated with Diphtheria proteins
Recommended…
for all children <2 years
and for unvaccinated children between 24 and 59 months old who are at high risk for pneumococcal infections
…will PCV-7 ↑ IPD from non-vaccine serotypes

68. METHODS:
laboratory-based data from Active Bacterial Core surveillance to measure disease caused by antibiotic-nonsusceptible pneumococci from
Cases of invasive disease were identified in 8 surveillance areas
Isolates underwent serotyping and susceptibility testing
RESULTS:
penicillin-nonsusceptible strains and
cases per 100,000
2004, 2.7 cases per 100,000 (↓ of 57%; 95% CI, 55 to 58%)
strains not susceptible to multiple antibiotics
cases per 100,000
2004, 1.7 cases per 100,000 (↓ 59%; 95% CI, 58 to 60%)
Children < 2 years (penicillin-nonsusceptible strains)
(↓ 81%; 95% CI, 80 to 82%).
> 65 years of age (penicillin-nonsusceptible strains)
(↓ 49%)
CONCLUSIONS: The rate of antibiotic-resistant invasive pneumococcal infections ↓ in young children and older persons after the introduction of the conjugate vaccine.

69. PREVNAR (PCV7)
Heptavalent Pneumococcal Vaccine

70. Fever of Uncertain Source
Most children have a virus
How common is occult bacteremia?
What tools can we use?

71. CBC (pre-PVC7 data) WBC > 15/L » 3-4% bacteremia
Sens 74-86%
Spec 55-77%
WBC > 20/L » 8-10% bacteremia
Varies with the organism
EColi ↑WBC compared with controls
Salmonella/Staph/N.Meningitidis Ø∆
CBC is not super helpful in identifying unsuspected bacteremia in febrile kids

73. Low Risk High Risk ≥2 PCV7 vaccines No High risk criteria Temp ≤40oC
Contact with meningococcal dz
Petechiae
Prolonged gastroenteritis
Abnormal Urinalysis

74. Urine Culture UTI is common FUS in 2 month – 2 year olds
Febrile UTI in children <5y
75% have upper tract disease**
Renal scarring 9-38%***
hypertension
chronic renal failure
toxemia in pregnancy
* Hoberman, A., H. P. Chao, D. M. Keller, R. Hickey, H. W. Davis, and D. Ellis Prevalence of urinary tract infection in febrile infants. J.Pediatr.123:17–23. **
*** Benador, D., N. Benador, D. Slosman, B. Mermillod, and E. Girardin Are younger children at highest risk of renal sequelae after pyelonephritis? Lancet 349:17–19.

75. Case
18 month ♀
Fever for 3 days
No alternative source of fever

76. Case
18 month ♀
Fever for 24 hours
No alternative source of fever

77. Case 11 month ♂ Fever for 3 days Uncircumsized
No alternative source of fever

78. Who do we screen? UTI Symptoms:
Dysuria/Frequency/Urgency
Suprapubic discomfort
Flank pain
But young kids present non-specifically
poor feeding
Vomiting
Irritability
Jaundice (in newborns)
Fever alone

79. UTI History Diarrhea/Vomiting Strong smelling urine Abd/Flank Pain
Failure to thrive
Fever
New incontinence
Risk Factors
Male
Uncircumcised
<6 months
Caucasian Race
Fever ≥ 39oC
Female
<2 years
Caucasian Race
Fever ≥ 39oC

80. Screening tests for urinary tract infection in children: a meta-analysis
Objective:  To develop a clinical prediction rule to identify febrile young girls needing urine culture for evaluation of UTI
Design:  Prospective cohort study
Setting:  Urban children's hospital emergency department
Patients:  Girls younger than 2 years (N=1469) presenting to the emergency department with fever (temperature 38.3°C) and without an unequivocal source
Main Outcome Measures: 
UTI - defined as a catheterized urine culture with pure growth of 104 colonies/mL
Clinical prediction rules were developed using multiple logistic regression
Results:  The presence of 2 or more…
< 12 months old,
white race
temperature of 39.0°C or higher
fever for 2 days or more
absence of another source of fever on examination—
…predicted UTI with a sensitivity of 0.95 (95% CI, ) and
specificity of 0.31 (95% CI, )
Conclusion:  Using this clinical decision rule, a strategy of obtaining urine cultures from girls younger than 2 years with a score of 2 or more would lead to identification of 95% of children with UTI and elimination of 30% of unnecessary urine cultures.
Gorelick, M. H., and K. N. Shaw Screening tests for urinary tract infection in children: a meta-analysis. Pediatrics 104:e54.

81. Urine Culture Girls 2-24 months Boys – No Decision Rule
…that I could find

83. Chest X-ray Children less than 2 yrs ?Occult pneumonia
Temp >38o
Prevalence X%
?Occult pneumonia
Viral vs Bacterial
Cost of CXR

84. Methods: n=197 Febrile infants ≤3months
Hx, PE
CXR
…other labs
?Combined these results with the results from 2 other studies
N(total)=617 infants

85. Conclusions: CXRs are not useful in asymptomatic kids
Results:
Chance of a CXR finding in an asymptomatic child 1.02% (95%CI)
Conclusions: CXRs are not useful in asymptomatic kids

87. Response to Anti-Pyretic
The use of antipyretics should be noted
However, a response (or lack thereof) to antipyretic medications does not predict whether the underlying cause is bacterial or viral
Baker MD, Fosarelli PD, Carpenter RO. Childhood fever: correlation of diagnosis with temperature response to acetaminophen.
Pediatrics 1987;80(3):315–8.
Baker RC, Tiller T, Bausher JC, et al. Severity of disease correlated with fever reduction in febrile infants. Pediatrics
1989;83(6):1016–9.
Huang SY, Greenes DS. Effect of recent antipyretic use on measured fever in the pediatric emergency department. Arch
Pediatr Adolesc Med 2004;158(10):972–6.
Torrey SB, Henretig F, Fleisher G, et al. Temperature response to antipyretic therapy in children: relationship to occult
bacteremia. Am J Emerg Med 1985;3(3):190–2.
Yamamoto LT, Wigder HN, Fligner DJ, et al. Relationship of bacteremia to antipyretic therapy in febrile children. Pediatr
Emerg Care 1987;3(4):223–7.

88. Case 6 week ♀ Tactile fever measured by Mom In the ED
Baby looks good
Now: afebrile
Mom asks “could this be from bundling little Emily too tightly?”

89. Bundling Can cause ↑ in skin temp Should not cause ↑ in rectal temp
If you are concerned, unbundle the child and repeat the measurement in min
Believe it if…
The kid looks good
Has not received antipyretics
The parents are reliable
Grover G, Berkowitz CD, Thompson M, et al. The effects of bundling on infant temperature. Pediatrics 1994;94(5):669–73

90. Thanks
Dr. Adam Oster
Dr. Marc Francis

92. Acetaminophen

93. (Antipyretics/ NSAIDs act here)
Infectious agents / Toxins / Mediators of inflammation (Pyrogens)
stimulate
Monocytes / Macrophages / Endothelial cells / Other cell types
release
Pyrogenic cytokines - IL- 1, TNF, IL- 6, IFNs
Anterior hypothalamus (Mediated by PGE2)
results in
Elevated thermoregulatory set point
leads to
Increased Heat conservation (Vasoconstriction/ behaviour changes) Increased Heat production (involuntary muscular contractions)
result in
F E V E R
(Antipyretics/ NSAIDs act here) 

95. Fever Good? Many pathogenic bacteria require iron for their growth
fever is associated with:
↓ serum iron
↑ in the iron-binding protein, Ferritin
Therefore ↓ free iron in the blood
In vitro:
↑ lymphocyte transformation response to mitogen
↑ bactericidal activity of polymorphonuclear leukocytes
↑ production of interferon with ↑ temperature
However, as temperature approached 40 ºC (104 ºF) in these experiments, most of the functions fell to below baseline levels

96. Fever Good? Fish and Lizards Cold-blooded (poikilotherms)
Develop fever in response to infection by moving to the warmest external environment available
Fever can be prevented
No confounding with ASA
↑ mortality when the febrile response is prevented by denying the animals access to a warmer environment

97. Fever Good? Rabbits Infected with Pasteurella multocida
Found that survival increased with moderate fever
However, fevers greater than 2.25 ºC > baseline
survival rates decreased

98. Fever Good? Rats infected with Salmonella enteritidis
Demonstrated ↑ mortality in those with high fever induced by cooling the hypothalamus
It seems that while fever of moderate degree can enhance certain immunologic responses, these effects may be diminished or even reversed at high body temperatures

99. What about Kids?

100. Design: Randomized, double-blind, placebo-controlled trial
Setting: Office- and hospital-based pediatric practices
Patients: 72 children between 1-12 years of age
31 received placebo and 37 received acetaminophen
Interventions: Acetaminophen 10 mg/kg/dose, was given at 8 am, 12 pm, 4 pm, and 8 pm for 4 days. Placebo was given to the control group.
Measurements and main results: The following results were better in the placebo group (p<.05):
time to total scrabbing
5.6 days (SD 2.5) versus 6.7 days (SD 2.3)
itching on day 4 in the placebo group
(symptom score 2.9 (SD 0.20) vs 2.2 (SD 0.26))
Conclusions: Acetaminophen does not alleviate symptoms in children with varicella and may prolong illness

101. Fever Bad? ↑ metabolic rate ↑ oxygen consumption
↑ carbon dioxide production
↑ demands on the CV and pulmonary systems
↑ demands may be detrimental and may offset any immunologic benefit from the fever
Fever can aggravate cerebral injury
Fever often makes patients uncomfortable
Fever can precipitate febrile convulsions
Disturbing
May lead to invasive procedures such as lumbar punctures

102. Relationship of Hypothalamic Set Point to Body Temperature

103.  Normal temperatures at different sites
Body site
Type of thermometer
Normal range, mean (°C)
Fever (°C)
Axilla
Hg in glass, electronic
34.7–37.3, 36.4
37.4
Sublingual
35.5–37.5, 36.6
37.6
Rectal
36.6–37.9, 37.0
38.0
Ear
Infrared emission
35.7–37.5, 36.6