A neonate born 2 hours ago is admitted to the neonatal intensive care unit due to prematurity. He was born at 32 weeks gestation to a 30-year-old primigravida via a precipitous, forceps-assisted delivery due to a nonreassuring fetal heart rate. Rupture of membranes occurred 5 hours before delivery and appeared clear. The mother received betamethasone during labor. In the delivery room, the patient was placed on continuous positive airway pressure due to tachypnea and moderate intercostal and subcostal retractions with low oxygenation saturations. He continued to have desaturations requiring increasing levels of flow. The patient was subsequently intubated, and umbilical lines were placed. Temperature is 36.9 C (98.4 F), pulse is 170/min, and respirations are 40/min. Pulse oximetry is 90% on 40% oxygen. Cardiac examination shows regular rate and rhythm without murmurs. Lung examination shows equal and coarse mechanically ventilated breath sounds bilaterally. The abdomen is protuberant but soft. A chest radiograph is obtained. Which of the following findings is most likely seen on imaging?

Question

A neonate born 2 hours ago is admitted to the neonatal intensive care unit due to prematurity.  He was born at 32 weeks gestation to a 30-year-old primigravida via a precipitous, forceps-assisted delivery due to a nonreassuring fetal heart rate.  Rupture of membranes occurred 5 hours before delivery and appeared clear.  The mother received betamethasone during labor.  In the delivery room, the patient was placed on continuous positive airway pressure due to tachypnea and moderate intercostal and subcostal retractions with low oxygenation saturations.  He continued to have desaturations requiring increasing levels of flow.  The patient was subsequently intubated, and umbilical lines were placed.  Temperature is 36.9 C (98.4 F), pulse is 170/min, and respirations are 40/min.  Pulse oximetry is 90% on 40% oxygen.  Cardiac examination shows regular rate and rhythm without murmurs.  Lung examination shows equal and coarse mechanically ventilated breath sounds bilaterally.  The abdomen is protuberant but soft.  A chest radiograph is obtained.  Which of the following findings is most likely seen on imaging?

Quizplus · Accepted Answer

11ec25c8_d721_3fd4_bc81_e3d887385129_MD0003_00 This neonate with severe respiratory distress most likely has neonatal respiratory distress syndrome (RDS), a condition that occurs almost exclusively in premature neonates. RDS is due to surfactant deficiency, which causes increased alveolar surface tension, resulting in alveolar collapse and diffuse atelectasis. Patients develop tachypnea, increased work of breathing (eg, retractions), and cyanosis within minutes to hours after birth. Breath sounds are typically symmetric and coarse but decreased. Chest x-ray findings in neonatal RDS include a diffuse reticulogranular (ground-glass) pattern of the lungs due to widespread atelectasis. Low lung volumes are also characteristic. Diffuse alveolar collapse results in air bronchograms, which represent patent, air-filled bronchioles surrounded by opacified alveoli. Antenatal corticosteroids, which promote fetal surfactant production, can prevent or reduce the severity of RDS but typically must be given >24 hours before delivery to be effective. (Choice A) Coarse lung markings with cystic changes can be seen in bronchopulmonary dysplasia (BPD), or chronic lung disease that can occur in patients with prolonged (ie, >1 month) oxygen therapy. RDS is the major risk factor for this condition, but this patient's age is inconsistent with a BPD diagnosis. (Choice C) Interstitial infiltrates with prominent interlobar fissures is characteristic of transient tachypnea of the newborn, a benign condition due to delayed resorption of alveolar fluid often seen in premature neonates. Although oxygen administration and continuous positive airway pressure may be required, this patient's need for invasive respiratory support makes this diagnosis unlikely. Interstitial infiltrates with prominent interlobar fissures (Choice D) Patchy bilateral infiltrates and lung hyperinflation are seen in meconium aspiration syndrome, which most commonly occurs in term and post-term neonates. Severe respiratory distress immediately after birth and coarse breath sounds are typical, but this premature patient's clear (as opposed to meconium-stained) amniotic fluid makes this diagnosis unlikely. (Choice E) A pneumothorax, which is seen on chest x-ray as a radiolucent zone between the lungs and chest wall, can cause sudden onset or acute worsening of respiratory distress in a neonate, particularly if mechanically ventilated. In contrast to this patient's examination, asymmetric breath sounds would be expected. chest x-ray Educational objective: Neonatal respiratory distress syndrome, seen in premature neonates with surfactant deficiency, causes increased work of breathing and hypoxemia. Atelectasis and diffuse alveolar collapse are seen on chest x-ray as a reticulogranular pattern (ie, ground-glass appearance) with air bronchograms. References: Respiratory distress in the newborn. (http://www.ncbi.nlm.nih.gov/pubmed/25274969)

A Neonate Born 2 Hours Ago Is Admitted to the Neonatal