RESPIRATORY DISTRESS SYNDROME NEWBORN

respiratory distress syndrome complications:
• Acute complications include the following:
o Alveolar rupture: Suspect air leak (ie, pneumothorax, pneumomediastinum, pneumopericardium, interstitial emphysema) when an infant with RDS suddenly deteriorates with hypotension, apnea, or bradycardia or when metabolic acidosis is persistent.

o Infections may complicate the management of RDS and may manifest in a variety of ways, including failure to improve, sudden deterioration, or a change in white blood cell count or thrombocytopenia. Also, the use of invasive procedures (eg, venipunctures, catheter insertion, use of respiratory equipment) and the use of postnatal steroids provide access for organisms that may invade the immunologically compromised host. With the advent of surfactant therapy, infants who are smaller and more ill are surviving with an increase in the incidence of septicemia secondary to staphylococcal epidermidis and/or infection by Candida species. When septicemia is suspected, obtain blood cultures from 2 sites and place the infant on appropriate antibiotics until the culture results are obtained.

o Intracranial hemorrhage and periventricular leukomalacia: Intraventricular hemorrhage is observed in 20-40% of premature infants with greater frequency in infants with RDS who require mechanical ventilation. Cranial ultrasound is performed within the first week and thereafter as indicated in premature infants younger than 32 weeks' gestation. Prophylactic indomethacin therapy and antenatal steroids have decreased the frequency of intracranial hemorrhage in these patients with RDS. Hypocarbia and chorioamnionitis are associated with an increase in periventricular leukomalacia.

o PDA with increasing left-to-right shunt may complicate the course of RDS, especially in infants weaned rapidly after surfactant therapy. Suspect PDA in any infant who deteriorates after initial improvement or has bloody tracheal secretions. Although helpful in the diagnosis of PDA, cardiac murmur and wide pulse pressure are not always apparent in critically ill infants. An echocardiogram enables the clinician to confirm the diagnosis. Treat PDA with indomethacin, which can be repeated during the first 2 weeks if the PDA reopens. In refractory incidents of RDS or in infants in whom indomethacin is contraindicated, surgically close the PDA.

o Occurrence of pulmonary hemorrhage increases in tiny premature infants, especially following surfactant therapy. Increasing PEEP on the ventilator and administering intratracheal epinephrine manages pulmonary hemorrhage. In some patients, pulmonary hemorrhage may be associated with PDA; treat pulmonary hemorrhage promptly in such individuals. In a retrospective study, intratracheal surfactant therapy has been used successfully, with the rationale that blood is an inhibitor of pulmonary surfactant.

o Suspect necrotizing enterocolitis and/or gastrointestinal perforation in any infant with abnormal abdominal findings on physical examination. A radiograph of the abdomen assists in confirming their presence. Spontaneous perforation (not necessarily as part of necrotizing enterocolitis) may occasionally occur in critically ill premature infants and has been associated with the use of steroids and/or indomethacin.

o Apnea of prematurity is common in immature infants, and its incidence has increased with surfactant therapy, possibly due to early extubation. Manage apnea of prematurity with methylxanthines (theophylline, caffeine) and CPAP or assisted ventilation in refractory incidents. Exclude septicemia, seizures, gastroesophageal reflux, and metabolic and other causes in infants with apnea of prematurity.

• Chronic complications include the following: o Bronchopulmonary dysplasia: BPD is a chronic lung disease and is defined as oxygen requirement at a corrected gestational age of 36 weeks. BPD is related directly to high volume and/or pressures that are used in mechanical ventilation, infections, inflammation, and vitamin A deficiency. BPD increases with decreasing gestational age. The postnatal use of surfactant therapy, gentler ventilation, vitamin A, and steroids reduces the severity of BPD.

o Clinical studies have demonstrated varying incidence of BPD, which has been attributed to an increase in the survival of smaller and more ill infants with RDS following the introduction of the above therapies. BPD may also be associated with Gastroesophageal Reflux or Sudden Infant Death Syndrome; hence, consider these entities in infants with unexplained apnea prior to discharge from the hospital.

o Retinopathy of prematurity (ROP): Infants with RDS and a PaO2 greater than 100 mm Hg are at a greater risk of developing ROP; hence, monitor PaO2 closely and maintain at 50-70 mm Hg. Although used in all premature infants, pulse oximetry is not helpful in preventing ROP in tiny infants because of the flat portion of the oxygen-hemoglobin dissociation curve. Eyes of all premature infants are examined at 34 weeks' gestation by an ophthalmologist and thereafter as indicated. If ROP progresses, laser therapy or cryotherapy is used to prevent retinal detachment and blindness. Monitor infants with ROP closely for refractive errors.

o Neurologic impairment: Neurologic impairment occurs in approximately 10-70% of infants and is related to the infant's gestational age, the extent and type of intracranial pathology, the presence of hypoxia, and the presence of infections. Hearing and visual handicaps further may compromise the development of these infants. They may develop a specific learning disability and aberrant behavior. Therefore, follow up periodically with these infants to detect those with neurologic impairment, and undertake appropriate interventions.

o Familial psychopathology: Infants with RDS are at a greater risk of child abuse and failure to thrive; therefore, obtain home clearance in conjunction with a nurse and social worker prior to discharge from the hospital. Encourage and document parental visits and the parent's interaction with the infant. Advise parents to spend time with their infants with RDS in a separate room prior to discharge, especially parents who are at high social risk (eg, teenagers) who also have extremely premature infants. Advise parents of infants who are discharged on oxygen and/or on an apnea monitor, with gastrostomy or requiring tube feeding, or with a tracheostomy or other special needs to spend time with their infants with RDS in a separate room prior to discharge. Physicians who are skilled in recognizing the problems encountered in these infants should be involved with their ongoing care because of the high risk of morbidity and mortality in infancy.