Index of Suspicion in the Nursery

Abstract

The neonatal intensive care unit (NICU) team was called by a midwife at a birthing center, who wanted to transfer a newborn who was experiencing respiratory distress. The infant was born at term and was appropriate for gestational age, weighing 3,354 g. He was born via normal spontaneous vaginal delivery without complications to a Caucasian G1P0 mother who had negative serologies. History included an absence of premature rupture of the membranes (PROM), meconium, nuchal cord, or maternal fever. Apgar scores were 9 at both 1 and 5 minutes. At 2.5 hours after birth, the baby was noted to be “ashen,” had a respiratory rate of 68 breaths/min with slight retractions, and had an oxygen saturation of 85% to 90%, for which blow-by oxygen was administered. At 3.5 hours after birth, the birthing center, unable to maintain oxygen saturation at greater than 82%, called emergency medical services to transfer the neonate to the NICU. The presumptive diagnosis made by emergency medical services was “respiratory distress of unknown origin, potentially unstable.” No maternal or neonatal records arrived with the baby.On presentation to the NICU, the patient had a respiratory rate of 110 breaths/min, oxygen saturation of 82% on room air, mild substernal retractions, and labored breathing with blood pressures and pulses equal and symmetric. Blow-by oxygen kept the saturation in the low 90s, so the infant was placed on continuous positive airway pressure (NCPAP) with an Fio2 of 100%. Umbilical artery catheter and umbilical vein catheter lines were placed, blood specimens were sent for laboratory analysis (including serial arterial blood gas, complete blood count, blood cultures, and electrolytes), and broad-spectrum intravenous antibiotics were initiated. Chest radiography demonstrated diffuse pulmonary vascular markings, with dirty lung fields and normal cardiac silhouette (Fig. 1).The neonate could not be weaned off of 100% Fio2 until 12 hours after birth. With the known history, the cause of the respiratory distress remained obscure. Persistent pulmonary hypertension of the newborn was the initial consideration on transfer of an infant needing 100% oxygen in severe respiratory distress. However, this diagnosis was unlikely, given the lack of a pre- and postductal gradient. The vaginal birth with a typical labor curve made retained fetal lung liquid syndrome unlikely. In the absence of meconium, maternal fever, and PROM and negative maternal serologies, sepsis was not likely. The chest radiograph exhibiting what appeared to be overcirculation raised the possibility of total anomalous pulmonary venous return, but in the absence of a figure of eight-shaped heart and the early timing, this diagnosis was statistically unlikely. The high oxygen demand, severity of respiratory distress, absence of air leak on chest radiograph, and a normal echo ruled out other causes.At 9 hours after the birth, the neonatologist told the family, “The story is not making sense. When I look at the x-ray, all that comes to mind is the picture of an infant who drowned.” The grandmother replied, “Well, it was a water birth.”Only 1 to 2 mL/kg of fluid aspiration can cause pulmonary edema from drowning. On further elucidation of the history, the grandmother disclosed that the umbilical cord was cut and the newborn was lost under water in a bloody bath for an undetermined length of time amidst great chaos. The quantity of aspiration was unknown, but in this case, probably was sufficient to cause the marked alveolar and interstitial edema found on imaging that facilitated the hypoxia and respiratory distress.The role of oxygen as a bronchodilator was of critical importance in this case. NCPAP served to splint open the upper airway and increase the functional residual capacity of the lungs. Its immediate institution aided in alveolar recruitment while delivering warm, well-humidified (37.6°C) oxygen. In an agitated term baby whose Pco2 is less than 65 mm Hg, NCPAP is superior to mechanical ventilation, which can increase the risk of pneumothoraces and prompt further irritation of the neonate.This patient did well on NCPAP for 3 days until he was weaned to a nasal cannula and ultimately, room air on the fourth day after birth. He did not require intubation, received phototherapy for 5 days, and received 72 hours of antibiotics, which were discontinued when all cultures came back negative. Repeat radiography (Fig. 2) documented clearing of the lung fields. The infant was discharged 7 days after birth without sequelae.This case underscores the importance of being persistent in obtaining a thorough history, especially when confronted with an extramural delivery. It never can be underestimated how integral the history is to the diagnosis and management of a patient. Physicians should return to the history and physical examination when any element of a case is not as it seems. Further, it is of paramount importance for clinicians to be honest and admit to a diagnosis eluding them or not entirely fitting the clinical presentation and course.