Chapter 2: The High-Risk Infant: Commonalities of the NICU Graduate Born Premature and at Term

The High-Risk Infant: Commonalities of the NICU Graduate Born Premature and at Term

When people think of the high-risk infant, most often a premature baby comes to mind. This is because the daily census of an average neonatal intensive care unit is dominated by infants born preterm. While only about 10% of NICU admissions are for prematurity, with the majority of admissions being for sepsis evaluation and treatment, birth complications, or respiratory concerns, it is actually moderately premature infants who are the largest group of infants to receive days of neonatal intensive care. These more common acute diagnoses usually only require short NICU hospitalizations and, generally, long-term outcomes are favorable. Premature and very sick newborns often have a prolonged convalescence period, during which time their acute medical issues slowly improve, but they are also exposed to an environment that can have significant effects on their overall health. So, it is really the duration of NICU stay, in addition to illness severity and underlying diagnoses, which contributes to some NICU graduates being considered high risk in terms of long-term medical and developmental outcomes.

I. Issues common to premature and sick term infants in the NICU

1. Medical issues

   1. Respiratory

      1. Exposure to support devices

         Both mechanical ventilation and noninvasive respiratory support devices (nasal cannula) can further cause lung injury either directly (trauma) or indirectly (oxygen toxicity).

      2. Susceptibility to lung infections

      3. Pulmonary edema

      4. Airway reactivity

   2. Cardiovascular

      1. Blood pressure problems

         Both hypotension (usually during intensive care) and hypertension (usually during convalescence) are seen.

      2. Tachycardia and bradycardia Often influenced by medications or other underlying conditions

   3. GI and nutrition

      1. Poor growth

         Inadequate nutrition and high metabolic demands contribute to poor growth of term and preterm infants in the NICU.

      2. Poor bone health

         Caused by poor nutrition as well as some medications (diuretics)

      3. Gastroesophageal reflux

         Feeding tubes, sepsis, stress, as well as underlying anatomical differences (prematurity, CDH, abdominal wall defects, etc), all increase GER.

      4. Feeding problems (see below)

   4. Infectious concerns

      1. Either as a primary diagnosis necessitating NICU admission (typically in term infants, such as GBS sepsis) or as a contributor (such as chorioamnionitis causing premature birth)

      2. Risk of iatrogenic infection (CLABSI, VAP, etc)

      3. Susceptibility to serious infection caused by common pathogens (RSV)

   5. Hematologic

      1. Anemia from blood sampling or associated comorbidity

      2. At risk for thrombus formation

      3. Coagulation disorder (high or low platelets, etc)

   6. Endocrine issues

      1. Adrenal insufficiency, often secondary to glucocorticoid therapy during acute illness

      2. Problems with glucose metabolism (hyper- and hypoglycemia)

      3. Abnormal thyroid studies, often secondary to initial acute illness

      4. Disorders of calcium management, often related to nutritional status or concurrent medical treat-ments (diuretic therapy)

   7. Well child care

      1. Immunizations

         Often delayed due to acute illness or may not have been initiated in the NICU due to concerns of expos-ing other infants (rotavirus)

      2. Car seat safety

         May not “pass” due to underlying conditions

      3. Hearing screen

         Many infants in the NICU are at risk for hearing loss due to either underlying conditions (CDH, ELBW) ...