Preterm Infant

Born at 37 weeks of gestation or less.

  1. Pathophysiology-anatomical and physiological immaturity of body systems compromises ability to adapt to extrauterine environment and independent life.
    1. Interference with protective functions
      1. Temperature regulation-unstable, due to:
        1. Lack of subcutaneous fat.
        2. Large body surface area in proportion to body weight.
        3. Small muscle mass.
        4. Absent sweat or shiver responses.
        5. Poor capillary response to changes in environmental temperature.
      2. Resistance to infection-low, due to:
        1. Lack of immune bodies from mother (these cross placenta late in pregnancy).
        2. Inability to produce own immune bodies (immature liver).
        3. Poor WBC response to infection.
      3. Immature liver
        1. Inability to conjugate bilirubin liberated by normal breakdown of RBCs-increased susceptibility to hyperbilirubinemia and kernicterus.
        2. Immature production of clotting factors and immune globulins.
        3. Inadequate glucose stores increased susceptibility to hypoglycemia.
    2. Interference with elimination: immature renal function-unable to concentrate urine-precarious fluid/electrolyte balance.
    3. Interference with sensory-perceptual functions: CNS-immature-weak or absent reflexes and fluctuating primitive control of vital functions.
  2. Etiology: often unknown; preterm labor.
    1. Iatrogenic-EDB miscalculated for repeat cesarean birth (rare).
    2. Placental factors
      1. Placenta previa.
      2. Abruptio placentae.
      3. Placental insufficiency.
    3. Uterine factors
      1. Incompetent cervix.
      2. Overdistention (multifetal gestation, polyhydramnios).
      3. Anomalies (myomas).
    4. Fetal factors
      1. Malformations.
      2. Infections (rubella, toxoplasmosis, HIVpositive status, AIDS, cytomegalic inclusion disease).
      3. Multifetal gestations (twins, triplets).
    5. Maternal factors
      1. Severe physical or emotional trauma.
      2. Coexisting disorders (PIH, hypertension, heart disease, diabetes, malnutrition).
      3. Infections (streptococcus, syphilis, bacterial vaginosis, pyelonephritis, pneumonia, influenza, leukemia, UTI).
    6. Miscellaneous factors
      1. Close frequency of pregnancies.
      2. Advanced maternal age.
      3. Heavy smoking.
      4. High-altitude environment.
      5. Cocaine use.
  3. Factors influencing survival:
    1. Gestational age.
    2. Lung maturity.
    3. Anomalies.
    4. Size.
  4. Causes of mortality (in order of frequency):
    1. Abnormal pulmonary ventilation.
    2. Infection.
      1. Pneumonia.
      2. Septicemia.
      3. Diarrhea.
      4. Meningitis.
    3. Intracranial hemorrhage.
    4. Congenital defects.
  5. Disorders affecting fluid-gas transport: RDS
    1. Pathophysiology-insufficient pulmonary surfactant (lecithin) and insufficient number/ maturity of alveoli predispose to atelectasis; alveolar ducts and terminal bronchi become lined with fibrous, glossy membrane.
    2. Etiology:
      1. Primarily associated with prematurity.
      2. Other predisposing factors:
        1. Fetal hypoxia-due to decreased placental perfusion secondary to maternal bleeding (abruptio) or hypotension.
        2. Birth asphyxia.
        3. Postnatal hypothermia, metabolic acidosis, or hypotension.
    3. Factors protecting neonate from RDS:
      1. Chronic fetal stress-due to maternal hypertension, PIH, or heroin addiction.
      2. PROM.
      3. Maternal steroid ingestion (betamethasone).
      4. Low-grade chorioamnionitis.
    4. Assessment:
      1. Usually appears during first or second day after birth.
      2. Signs of respiratory distress:
        1. Nasal flaring.
        2. Sternal retractions.
        3. Tachypnea (60 beats/min or more).
        4. Cyanosis-central.
        5. Expiratory grunt.
        6. Increasing number and length of apneic episodes.
        7. Increasing exhaustion.
      3. Respiratory acidosis-due to hypercapnea and rising CO2 level.
      4. Metabolic acidosis-due to increased lactic acid levels and falling pH.
    5. Analysis/nursing diagnosis:
      1. Impaired gas exchange related to lack of pulmonary surfactant secondary to preterm birth, intrapartal stress and hypoxia, infection, postnatal hypothermia, metabolic acidosis, or hypotension.
      2. Altered nutrition, less than body requirements, related to poor feeding secondary to respiratory distress, caloric demand.
    6. Nursing care plan/implementation:
      1. Goal: reduce metabolic acidosis, increase oxygenation, support respiratory efforts.
        1. Ensure warmth (isolette at 97.6°F).
        2. Warmed, humidified O2 at lowest concentration required to relieve cyanosis, through hood, nasal prongs, or endotracheal tube.
        3. Monitor continuous positive airway pressure (CPAP)-oxygen-air mixture administered under pressure during inhalation and exhalation to maintain alveolar patency.
        4. Position: side-lying or supine with neck slightly extended (“sniffing” position); arms at sides.
        5. Suction pm with bulb syringe-for excessive mucus.
      2. Goal: modify care for infant with endotracheal tube.
        1. Disconnect tubing at adapter.
        2. Inject 0.5 mL sterile normal saline.
        3. Insert sterile suction tube, start suction, rotate tube, withdraw.
        4. Suction up to 5 seconds.
        5. Ventilate with bag and mask during procedure.
        6. Reconnect tubing securely to adapter.
        7. Auscultate for breath sounds and pulse.
      3. Goal: maintain nutrition/hydration.
        1. Administer fluids, electrolytes, calories, vitamins, minerals PO or IV, as ordered.
        2. I&O.
      4. Goal: prevent secondary infections.
        1. Strict aseptic technique.
        2. Handwashing.
      5. Goal: emotional support of infant.
        1. Gentle touching.
        2. Soft voices.
        3. Eye contact.
        4. Rocking.
      6. Goal: emotional support of parents.
        1. Keep informed of status and progess.
        2. Encourage contact with infant-to promote bonding, understanding of treatment.
      7. Goal: minimize possibility of iatrogenic disorders associated with oxygen therapy.
    7. Evaluation/outcome criteria:
      1. Respiratory distress treated successfully; infant breathes without assistance.
      2. Infant completes successful transition to extrauterine life.
  6. Iatrogenic (oxygen toxicity) disorders: retinopathy of prematurity
    1. Pathophysiology-intraretinal hemorrhage-fibrosis-retinal detachment-loss of vision.
    2. Etiology-prolonged exposure to high concentrations of oxygen.
    3. Assessment-only perceptible retinal change is vasoconstriction. Note: Arterial blood (PaO2) gas readings less than 50 or more than 80 mm Hg.
    4. Nursing care plan/implementation: Goal: prevent disorder. Maintain PaO2 of 50-70 mm Hg.
    5. Evaluation/outcome criteria:
      1. Successful recovery from respiratory distress.
      2. No evidence of retinopathy.
  7. Iatrogenic (oxygen toxicity) disorders: bronchopulmonary dysplasia (BPD)
    1. Pathophysiology-damage to alveolar cells result in focal emphysema.
    2. Etiology-positive pressure ventilation (CPAP and PEEP) and prolonged administration of high concentrations of oxygen.
    3. Assessment-monitor for signs of:
      1. Tachypnea.
      2. Increased respiratory effort.
      3. Respiratory distress.
  8. Intraventricular hemorrhage
    1. Pathophysiology-rupture of thin, fragile capillary walls within ventricles of the brain (more common in preterm).
    2. Etiology:
      1. Hypoxia.
      2. Respiratory distress.
      3. Birth trauma.
      4. Birth asphyxia.
      5. Hypercapnia.
    3. Assessment:
      1. Hypotonia.
      2. Lethargy.
      3. Hypothermia.
      4. Bradycardia.
      5. Bulging fontanels.
      6. Respiratory distress or apnea.
      7. Seizures.
      8. Cry: high-pitched whining.
    4. Nursing care plan/implementation: Goal: supportive care-to promote healing.
      1. Monitor vital signs.
      2. Maintain thermal stability.
      3. Ensure adequate oxygenation (may be placed on CPAP).
    5. Evaluation/outcome criteria:
      1. Condition stable, all assessment findings within normal limits.
      2. No evidence of residual damage.