AANP Family Nurse Practitioner (FNP) Certification ExamAssessmentEasy
A 6-month-old infant is brought to the clinic by their parents due to a 2-day history of fussiness, poor feeding, and a temperature of 101.5°F (38.6°C). On examination, the infant appears irritable, and the anterior fontanelle is bulging. Which of the following diagnostic tests is most immediately indicated?
- ALumbar puncture (LP)
- BComplete blood count (CBC) with differential
- CChest X-ray (CXR)
- DUrine culture (UC)
Show answer & explanationAnswer & explanation
Correct answer: A. Lumbar puncture (LP)
The symptoms of fussiness, poor feeding, fever, and a bulging anterior fontanelle in an infant are highly suggestive of meningitis. A lumbar puncture is the definitive diagnostic test for meningitis, allowing for cerebrospinal fluid analysis.
Why the other options are wrong
- B. While a CBC is important in evaluating infection, it is not definitive for meningitis and delays critical diagnosis.
- C. A chest X-ray is used to assess for pulmonary infections, which is less likely given the neurological signs.
- D. A urine culture is important for ruling out urinary tract infection, but meningitis is a more emergent concern with these specific signs.
Infant Meningitis Diagnosis
Meningitis in infants presents with non-specific symptoms but can rapidly progress. A bulging fontanelle is a key sign, and lumbar puncture is crucial for diagnosis.
- Non-specific symptoms: irritability, poor feeding, fever.
- Key physical finding: bulging anterior fontanelle.
- Definitive diagnosis: lumbar puncture with CSF analysis.
Memory trick: Fever, fuss, and a bulging brain fountain, get that spinal fluid flowing!