Fever in Infants Younger than Two Months

Errors in diagnosing meningitis resulted in the highest average indemnity payment ($437,000) for Emergency Medicine in 2006 (PIAA).

Most infants with febrile conditions have minor illnesses. However, as we all know, a serious and life-threatening condition could be looming, and these infants can rapidly deteriorate, making an early diagnosis critical.

What follows are some key points to consider when diagnosing and treating this population:

• Clinical assessment alone may not be sufficient to reliably rule out serious bacterial infections.



• Infants younger than 29 days old with a fever should be presumed to have a serious bacterial infection (Level A—ACEP recommendation).
  
  • Management must include hospital admission, complete diagnostic evaluation (septic work-up), and timely, empiric antibiotic therapy (Kirchner, 1999).
  
  
  
  • Infants under 29 days of age cannot reliably be identified as non-toxic and safely treated as outpatients.
  
  
  
  • A serious bacterial illness was reported in 12.6% of infants younger than 29 days of age with fever (Kirchner, 1999).
  
  
  



• Infants 29 days to two months who appear toxic should have a sepsis workup.



• Lumbar puncture is usually done in infants less than 2 months of age with a fever, but many experienced clinicians trust their clinical exam to exclude meningitis in infants older than 4 to 8 weeks.



• If an infant appears “toxic,” do not delay the initiation of antibiotics. Generally, antibiotic therapy should be initiated as soon as possible (under an hour) after determining the infant appears “toxic.”

Consider these treatment and documentation guidelines:

• Fever is a rectal temperature or reported



• temperature > 100.4°.



• Delayed capillary refill can be a sign of hypoperfusion due to shock.
  
  • Septic infants in “compensated shock” preserve blood pressure, then can suddenly develop “decompensated shock” drop their blood pressure.
  
  
  
  • Fever is a symptom—documenting a reduced fever after acetaminophen is “only treating yourself” and has no diagnostic value.
  
  
  
  • The neck exam for meningismus is unreliable in infants.
  
  
  
  • If the infant has bloody diarrhea, obtain a stool culture, to include culture for E. coli O157:H7.
  
  
  
  • If an infant older than 29 days with a fever of unknown etiology is discharged, the physician should arrange specific follow-up in 12-24 hours. It is not enough to instruct “see your pediatrician if symptoms worsen or do not improve.”
  
  
  

Ensure documentation of a complete assessment, including pertinent negatives:

• Anterior Fontanelle



• I & O – appetite, infant interested in eating



• Irritability or lethargy



• Activity level



• Immunization history



• Bloody diarrhea



• Neck exam



• Pulse oximetry



• Absence of rashes – skin color



• Respiratory distress, tachypnea, rales



• Prematurity or any birth problems should be documented



• Serial examinations and close follow-up

The sepsis workup in the infant under 2 months includes:

• CBC



• Cath urinalysis (UA) with culture (even if UA is negative)



• Chest x-ray (if signs present referable to respiratory tract)



• Blood cultures



• Lumbar puncture with cerebral spinal fluid (CSF) culture (mandatory under 30 days of age, recommended 4 – 8 weeks but may not be done by experienced clinicians as infants approach 2 months of age)