Anemia of Prematurity - Portal Neonatal

Lab Studies:
WORKUP Section 5 of 11
• A CBC and cultures of blood, urine, and spinal fluid are necessary if a serious bacterial
infection is suspected.
• Tests for serum ammonia, urine and serum amino acid, and organic acid levels are useful if a
metabolic disorder is suspected.
• Serum electrolyte, calcium, and glucose levels can help in diagnosing a recent stressful
condition, metabolic process, or chronic hypoventilation.
• A stool specimen test for botulism helps if the infant with apnea has associated constipation
and hypotonia.
Imaging Studies:
• Chest radiography and/or radionuclide milk scanning can help if the child has persistent, yet
unexplained, lower airway symptoms.
• Upper airway evaluation, including lateral neck radiography and otolaryngologic evaluation, is
useful for cases of fixed or recurrent stridor, as well as cases of unexplained pathologic
obstructive apnea.
• Imaging studies of the head are necessary when an intracranial hemorrhage is suspected or
when findings include dysmorphic features, abnormal neurologic results, or mental status
changes.
• A barium swallow study is useful if the infant has signs of swallowing dysfunction or anatomic
anomalies (eg, esophageal web, tracheoesophageal fistula).
• A gastric emptying study and abdominal sonography are useful in patients whose clinical
picture includes a generalized GI motility disorder or pyloric stenosis.
Other Tests:
• Perform a continuous multichannel recording to measure the chest-wall movement, nasal
and/or oral airflow (or change in air temperature), oxygen saturation, and heart rate trend. (A
2-channel pneumogram that is used to measure only chest-wall excursion and heart rate trend
provides insufficient information.) The following results are diagnostic:
o Central apnea - Absence of nasal airflow and wall movement
o Obstructive apnea - Lack of airflow despite chest-wall movement
o Mixed apnea - Combined results of central and obstructive apnea
• If GER is suspected, obtain an intraesophageal pH recording by means of multichannel
recording.
• Consider obtaining an electroencephalogram (EEG) in infants in whom apneic seizures are
suspected or in whom persistent pathologic central apnea without an identifiable cause is
present.
• Obtain an echocardiogram (ECHO), and consult a cardiologist if the history or physical
examination results (eg, feeding difficulties, heart murmur, cyanosis) suggest cardiac disease.
• Electrocardiographic (ECG) results are useful in patients with severe unexplained tachycardia
or bradycardia. Cardiac conduction abnormalities (eg, prolonged-QT syndrome) are rare but
important causes of infant apnea.
• Evaluate unilateral choanal stenosis and choanal atresia by passing a 5-8F feeding tube
through both nares. CT scanning is the method of choice for definitive diagnosis.