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Mark Bromley PGY 2 Adam Oster FRCPC

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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

16

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

59

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

72

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

82

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

86

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

91

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) 

94

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


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