Now that the weather is changing and the infectious season is starting, we are going to be seeing more patients with fevers. This is especially true of pediatrics. While most of this group will have a viral etiology, we are looking for the rare serious bacteria infection (SBI). SBI includes having bacteria where it should not be (UTI, bacteremia, meningitis, osteomyelitis, bacterial pneumonia, cellulitis, septic arthritis, and osteomyelitis) and is the reason for the aggressive approach to this population. This is a bulky topic, with a lot of information. However, I will attempt to emphasize some bullet points of the most common infections, management strategies, and treatment options available to us in the ED.
Definitions (1) (2)
- Threshold for concerning fever depends on age
- 0 – 3 months, 380 C (100.4 0 C)
- 3 – 36 months this rises to 390 C (102.20 F)
- Keep in mind the response to antipyretics
- Prevalence of SBI <90 days, 6 – 10%. After that it continues to significantly decrease
- Prevalence 3 – 7 %
- Most common cause of SBI
- Most common organism: E. coli
- Girls at higher risk than boys
- Bag collection false positive 85% of the time; however, if negative then can rule out infection
- Samples should be from sterile catheterization (or suprapubic aspiration)
- Defined as positive if >10,000 CFUs
- UA has high false negative rate
- Bacteria not around long enough to react to form nitrites
- Only gram negative bacteria produce nitrites
- Pyuria may not be initially present
- Gram stain, highly sensitive (93%)
- Urine culture is gold standard diagnosis
- Can occur even with existing source of infection
- Definitive source (pneumonia, meningitis, etc.) 1% of the time
- Less definitive (otitis media, gastroenteritis, URI) 4% of the time
Pneumonia (1, 4)
- Rare in children <90 days without one of the following signs or symptoms
- RR > 50 breaths/minute
- Rales, rhonchi, wheezes
- Retractions, grunting, stridor
- Cough, coryza
- Occult pneumonia can also occur, and is more likely present if highly febrile (> 390C, 102.20F) and significant leukocytosis (>20,000)
- Still, above parameters have not shown to increase risk in those less than 90 days without respiratory symptoms.
- Bottom line: CXR not mandatory for febrile child less than 90 days who is not presenting with respiratory symptoms
Meningitis (1-3, 5)
- Febrile infants <28 days carry 1% risk
- Decreases to <0.1% later in infancy
- Prevalence has decreased since Haemophilus influenza type B (Hib) vaccine
- Most common organisms in descending order Streptococcus agalactiae, E. coli, Listeria monocytogenes
- LP should be done on all patients 28 days or less
- Greater than 28 days, some debate exists
Occult Bacteremia (1, 2, 4)
- Definition: febrile and well appearing without a identifiable source on exam or ancillary testing
- If missed, high risk of developing serious sequelae
- Only 1 set of blood cultures needed
- Part of full septic work up in those < 28 days or ill appearing
- Should be included in any patient that will be started on antibiotics
Management (1, 2)
- All febrile infants less than 28 days, as well as any patient who is not well-appearing, should receive a full septic workup and be admitted with empiric antibiotics
- Greater than 28 days, many approaches exist
- The Boston, Philadelphia and Rochester criteria can be used for infants greater than 28 days who have low risk criteria (previously healthy with uncomplicated nursery stay, born term, well appearing). See chart below for a summary of each approach
- In depth management also discussed on the PEM ED Podcast by author Andy Sloas. This is broken down into two part series, and has great information. (Part 1(6); Part 2(7)
- Ampicillin 50 mg/kg PLUS
- Cefotaxime 50 mg/kg (ceftriaxone 100 mg/kg if > 29 days)
1 Mick NW. Pediatric Fever. In: Marx J, Hockenberger RS, Walls, RM, et al, editor. Rosen's Emergency Medicine: Concecpts and Clinical Practice. 8th ed. Philadelphia: Elseveir Saunders; 2014.
2 Nadkarni MD. Fever and Serious Bacterial Illness. In: Cline DM, Ma OJ, Cydulka RK, Thomas SH, Handel DA, Meckler GD, editors. Tintinalli's Emergency Medicine: Just The Facts. 3rd ed. China: McGraw-Hill; 2013.
3 Morley EJ, Lapoint JM, Roy LW, et al. Rates of positive blood, urine, and cerebrospinal fluid cultures in children younger than 60 days during the vaccination era. Pediatr Emerg Care. 2012 Feb;28(2):125-30.
4 American College of Emergency Physicians Clinical Policies C, American College of Emergency Physicians Clinical Policies Subcommittee on Pediatric F. Clinical policy for children younger than three years presenting to the emergency department with fever. Ann Emerg Med. 2003 Oct;42(4):530-45.
5 Martinez E, Mintegi S, Vilar B, et al. Prevalence and predictors of bacterial meningitis in young infants with fever without a source. Pediatr Infect Dis J. 2015 May;34(5):494-8.
6 Sloas A. PEM ED Podcast. Fever of Unknown Source - Part 1; 2011.
7 Sloas A. PEM ED Podcast. Fever of Unknown Source - Part 2; 2011.
8 Baker MD, Bell LM, Avner JR. Outpatient management without antibiotics of fever in selected infants. N Engl J Med. 1993 Nov 11;329(20):1437-41.
9 Jaskiewicz JA, McCarthy CA, Richardson AC, et al. Febrile infants at low risk for serious bacterial infection--an appraisal of the Rochester criteria and implications for management. Febrile Infant Collaborative Study Group. Pediatrics. 1994 Sep;94(3):390-6.
10 Dagan R, Powell KR, Hall CB, Menegus MA. Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis. J Pediatr. 1985 Dec;107(6):855-60.
11 Baskin MN, O'Rourke EJ, Fleisher GR. Outpatient treatment of febrile infants 28 to 89 days of age with intramuscular administration of ceftriaxone. J Pediatric. 1992 Jan;120(1):22-7.
Submitted by Dr. Michael Craddick, PGY-2