Anemia of Prematurity - Portal Neonatal

DIFFERENTIALS Section 4 of 10
Methylmalonic Acidemia
Other Problems to be Considered:
Brain tumors
Developmental defects
Infections
Inherited metabolic disorders such as disorders of urea cyclase deficiency
WORKUP Section 5 of 10
Lab Studies: No specific test excludes or confirms a diagnosis of HIE. The diagnosis is based on the
history and physical examination. All tests are performed to assess the severity of brain injury and to
monitor the functional status of systemic organs. Choice of tests depends on the evolution of
symptoms. As with any other disease, test results should be interpreted in conjunction with clinical
history and the findings of physical examination.
Imaging Studies:
o Serum electrolytes: In those affected by severe HIE, daily assessment of serum
electrolytes would be of value until the infant's status improves. Markedly low serum
sodium, potassium, and chloride in the presence of reduced urine flow and excessive
weight gain may indicate acute tubular damage or inappropriate antidiuretic hormone
(IADH), particularly during the initial 2-3 days of life.
o Similar changes during recovery, with increased urine flow, might indicate ongoing
tubular damage and excessive sodium loss relative to water loss.
o Renal function studies: Serum creatinine, creatinine clearance, and BUN suffice in
most cases.
• Since, in most HIE cases, imaging studies are inconsistent in revealing abnormal findings, a
normal imaging study finding cannot be used to rule out HIE.
• Cranial ultrasound: Ultrasound is portable and provides a quick assessment of brain lesions.
Although it reveals intracranial hemorrhages and cerebral edema (decreased ventricular size),
it is not ideal for detailed mapping of the posterior cranial fossa.
• CT scan of the head: This study, especially if done with contrast infusion, may reveal evidence
of cerebral edema (eg, obliteration of cerebral ventricles, blurring of sulci) manifested as
narrowness of the lateral ventricles and flattening of gyri. Areas of reduced density might
indicate regions of infarction. Rarely, evidence of hemorrhage in the ventricles may be seen.
o In suspected posterior cranial fossa hemorrhage, CT scan must be obtained as soon
as clinically feasible because early diagnosis helps in obtaining early neurosurgical
consultation.
o Intracranial hemorrhage is a rare finding in term infants; however, cerebral artery
occlusions and infarctions can be diagnosed with radiographic imaging studies.
• MRI is valuable in moderately severe and severe HIE, particularly to note the status of
myelination, white-grey tissue injury, and to identify preexisting developmental defects of the
brain. MRI is also useful during follow-up. In any newly diagnosed case of cerebral palsy, MRI
should be considered, since it may help in establishing the cause. However, the interpretation
of MRI in infants requires considerable expertise.
• MRI is valuable in moderately severe and severe HIE, particularly to note the status of
myelination, white-grey tissue injury, and to identify preexisting developmental defects of the