Neonatal Fever (Case 16)

Chapter 46 Neonatal Fever (Case 16)



Jennifer R. Rosenthal, MD




Case


A 17-day-old presents with a fever.




Differential Diagnosis











Sepsis Urinary tract infection (UTI)
Bronchiolitis Meningitis or encephalitis


Speaking Intelligently


When evaluating a febrile neonate, I remember that fever may be the only sign of a significant underlying infection. A history of fever at home should be taken seriously, even if the infant is afebrile on presentation. Fever is defined as a rectal temperature of 38°C (100.4° F). Distinguishing between neonates (from birth to 28 days) and young infants (29 to 60 days) is important, because neonates face greater risk for systemic infections, and even a thorough physical examination is unreliable. The term “rule out sepsis” (or “rule out serious bacterial infection” [SBI]) is used to describe the standard workup of a febrile neonate. Neonates hospitalized since birth have higher risk for infections, including nosocomial infections, than neonates admitted from home. Nonetheless, a complete workup is indicated, and some cases of SBI will be identified (see Chapter 77, Neonatal Sepsis).1



Patient Care



Clinical Thinking



• The workup for febrile neonates is relatively straightforward. A complete diagnostic evaluation, IV antibiotic administration, and hospital admission are all considered standard practice. In some cases, a positive rapid test such as respiratory syncytial virus (RSV) may change decision making.

• Young infants are approached differently. Here clinical judgment is used. For well-appearing febrile infants, laboratory testing is necessary to determine which patients are at risk for SBI. Any ill-appearing infant should be admitted for empirical antibiotics, regardless of initial laboratory results.

• Well-appearing infants who are discharged to home should have a follow-up examination and laboratory results checked within 24 hours.

• In a well-appearing infant (over 28 days), a lumbar puncture (LP) may be considered optional. However, if antibiotics are administered, an LP should be performed.

• Criteria for differentiation of high-risk patients (i.e., Rochester, Philadelphia, Boston) may be used to guide therapeutic decision making, although these were developed before the heptavalent (now 13-valent) Streptococcus pneumoniae vaccine.


History



• A detailed birth history is crucial.

• Gestational age?

• Prolonged rupture of membranes?

• Prenatal laboratory results, including group B streptococcus? Adequate treatment?

• Nursery course and any complications?

• Any sick contacts?

• Inquire about activity level.

• Alert or lethargic? (Use “lethargic” with caution; it describes a baby who is not just sleepy, but difficult to arouse.)

• Is the baby feeding normally?

• Increased irritability? Consolable?

Other symptoms:


• Upper respiratory symptoms?

• Vomiting?

• Diarrhea?

• Decreased wet diapers and/or foul-smelling urine?

• Has the fever been treated?

• Any factitious cause for fever such as excessive bundling, high ambient temperature, or inaccurate thermometer?


Physical Examination



• Vital signs: Rectal temperature, heart rate, respiratory rate, oxygen saturation, and growth parameters (weight, length, head circumference).

• General appearance: Does the infant appear toxic? Realize a seriously ill neonate may not be ill appearing.

• Cardiovascular: Is perfusion adequate? Note capillary refill and pulses.

• Respiratory: Good air movement? Retractions? Sounds on auscultation?

• Abdomen: Distended? Bowel sounds?

• Skin: Rashes? Look specifically for vesicles, petechiae, or evidence of cellulitis or abscesses such as mastitis.

• Neurologic: Alert? Irritable? Bulging fontanelle? Floppy?


Tests for Consideration



• Complete blood count (CBC) with manual differential. $116

• Low-risk criteria include a white blood cell count (WBC) >5000 and <15,000 µL

• Number of bands on the differential should be <1.5 × 109 cells/L

• Blood culture $152

• Urine dipstick $95

• Urinalysis and urine culture $243

• Lumbar puncture for cerebrospinal fluid (CSF): Cell count, glucose, protein, Gram stain, and culture

• A herpes simplex virus (HSV) polymerase chain reaction (PCR) should be sent for neonates who have risk factors for HSV, abnormal neurologic examination, or suspicious skin findings or are ill-appearing $300

• Rapid respiratory panel $325

• Coagulation studies: Prothrombin time and partial thromboplastin time $105


Imaging Considerations


→ Chest radiograph: If respiratory symptoms $231

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Related posts:

  1. The Special Needs Child
  2. Newborn Hearing Screen (Case 22)
  3. Pediatric Poisonings (Case 54)
  4. Note Writing

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Jul 18, 2016 | Posted by in PEDIATRICS | Comments Off on Neonatal Fever (Case 16)

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