Mother’s Own Milk for Severe Recurrent Respiratory Distress in a Preterm Infant

A 24-year-old primigravida woman was referred to maternal-fetal medicine for fetal left-sided hydrothorax detected during a routine scan at 28 weeks of gestation. A normal fetal chromosomal microarray was reported. The hydrothorax was severe, with associated mediastinal shift and polyhydramnios but without fetal hydrops. In utero thoracentesis was performed at 31 weeks of gestation. Thoracoamniotic shunting was not performed because of the advanced gestation. Because of rapid progression of the hydrothorax, the decision was made to proceed with preterm delivery.A female infant was delivered via cesarean section at 32 weeks 6 days of gestation with a birth weight of 2136 g. Following delivery, Apgar scores were 5 at 1 minute and 7 at 5 minutes. She was admitted to an intensive care unit on continuous positive airway pressure (CPAP) of 7 cm water and fraction of inspired oxygen 1.0. On general physical examination, no atypical facial findings were noted. The infant had severe respiratory distress, with diminished air entry on the left side and evidence of mediastinal shift toward right (Figure 1A). Heart sounds were normal with no murmur appreciated on auscultation. Thoracocentesis was performed to facilitate ventilation; 15 mL per kilogram of straw-colored fluid was drained slowly under guarded manner. Fluid analysis revealed a cell count of 8000 per micro liter with a predominance of lymphocytes (95%) and a triglyceride level of 40 mg/dl. Following the thoracentesis, the infant’s oxygen requirement was less than 30%. She did not require surfactant. A chest tube was inserted on the day of birth after the initial stabilization because of fluid reaccumulation (Figure 1B), which was removed on day 4 once the output became negligible. Investigations showed normal blood counts, glucose values, liver function tests, and other metabolic studies. Cord thyrotropin level and a repeat thyroid function test later were normal (laboratory values have been summarized below). An evaluation for intrauterine infections (toxoplasmosis, rubella, cytomegalovirus, herpes, and parvovirus) was unrevealing. Two-dimensional echocardiography demonstrated normal ventricular filling and function, with mild tricuspid regurgitation and age-appropriate pulmonary pressure with no evidence of pericardial effusion. Abdominal ultrasonography revealed no peritoneal fluid collection and ruled out organomegaly.The infant’s laboratory test results are as follows: Her white blood cell count was 28.5 × 103/μL (28.5 × 109/L), with 68% neutrophils and 21% lymphocytes, and her red blood cell count was 4.9 × 103/μL (4.9 × 109/L). Her hemoglobin levels were 18.4 g/dL (184.0 g/L), and her platelet count was 163 × 103/μL (163 × 109/L). Her sodium level was 138 mEq/L (138 mmol/L), potassium was 4.7 mEq/L (4.7 mmol/L), serum urea nitrogen was 21 mg/dl (7.49 mmol/L), creatinine was 0.7 mg/dl (61.88 umol/L), calcium was 9.2 mg/dL (2.3 mmol/L), phosphorus was 6.5 mg/dL (2.1 mmol/L), and alkaline phosphatase was 469 U/L. The aspartate aminotransferase test result was 18 U/L, and the serum glutamic pyruvic transaminase test result was 26 U/L. On day 4, her total serum bilirubin level was 9.1 mg/dl (155.6 mmol/L). Her direct bilirubin was 0.3 mg/dl (5.1 mmol/L). Soon after birth, her blood arterial pH was 7.18 (respiratory acidosis). Her lactate level was 1.5 mmol/L, and her bicarbonate level was 19.7. Her cord thyrotropin level was 5.51 uIU/ml. The results of her urinalysis were normal. Her blood culture featured no growth at 48 hours and 5 days.Enteral feedings were started on day 2 with mother’s own milk, volume was progressed, and fortification was added as per unit protocol. The infant transitioned off the CPAP on day 7 after chest radiograph and ultrasonography showed no evidence of reaccumulation. She reached full enteral feedings by the end of the first week and transitioned from gavage to oral feeds gradually. There was no recurrence of respiratory distress until the fourth week of age when the infant had an acute clinical deterioration with respiratory distress requiring CPAP of 6 cm H2O and fraction of inspired oxygen up to 0.40. Chest radiograph confirmed a moderate-sized pleural effusion (Figure 1C), which was drained with a chest tube. The output was milky in appearance (Figure 2). The respiratory distress resolved with drainage of the pleural fluid, and the infant was weaned to room air the next day. The fluid analysis showed a cell count of 52 000 per microliter with a predominance of lymphocytes (98%), triglyceride levels at 2341 mg/dL, and positive chylomicrons.Aspiration pneumoniaCongenital chylothoraxBacterial pneumoniaCongestive heart failureCongenital chylothorax fit with the timing of presentation and biochemical evaluation of the fluid in mind. Aspiration pneumonia does not routinely present with an effusion; however, this is an appropriate differential if the timing of respiratory decompensation parallels the introduction of oral feeding. Bacterial pneumonia may present with a parapneumonic effusion; however, there are often associated signs of pneumonia that persist after the drainage of pleural fluid. Congestive heart failure more commonly has a gradual presentation, and when associated with pleural effusion, the effusions are typical bilateral or right sided. In the absence of structural anomalies or dysrhythmia, the infant was at low risk to develop congestive heart failure.The 2 primary enteral feeding approaches for an infant with chylothorax are skimmed mother’s own milk or a medium chain triglyceride (MCT)-based formula. As MCT-based formula is not available in India, mother’s own milk was centrifuged in the laboratory at 5000 rotations per minute for 15 minutes until the fat layered at the surface to skim it (Figure 3). The fat layer was removed using a pipette, and the remaining low-fat milk was fed to the infant. The color of the pleural drain became straw colored, and the cell count and triglyceride levels decreased. The infant did not require medical management with octreotide. Later, MCT oil was added to fortify the mother’s skim milk before discharge to ensure adequate calories. Whole-exome sequencing showed homozygous variation of unknown significance for glycogen storage disease 1B. The infant did not show any signs of glycogen storage disease 1B during her newborn hospitalization through follow-up at 18 months.The infant gained adequate weight and attained age-appropriate developmental milestones. She received all her routine vaccinations. She was introduced to complementary feeding as early as 4 months of corrected age. Around the age of 1, the young toddler was challenged with oils and butter, which she tolerated well, and was gradually switched to regular cow milk. At 18 months chronological age, the infant did not have a history of any other significant illness except for recurrent episodes of viral-induced wheeze with no need for supplemental oxygen or hospitalization.Neonatal chylous disorders are rarely encountered by clinicians, with an incidence ranging from 1 in 10 000 to 24 000, and a male preponderance.1–4 However, chylothorax is the most common etiology for pleural effusion in the neonatal period and is more common on the right side.1,5 These complex disorders remain a diagnostic conundrum and result from heterogenous abnormalities in thoracic duct anatomy and variable physiological regression of lymphatic capillaries during the embryonic development.5 Chylous nature of any effusion is relatively easy to establish based on its appearance (Figure 2) and cytological and biochemical evaluation. The key differences between chylous and nonchylous fluid evaluation have been tabulated in Table 1. However, these disorders have an inherent high morbidity and mortality rate because of associated genetic abnormalities, syndromic associations, increased risk for infections because of relative immunodeficiency, and need for multiple invasive interventions.6The course of congenital chylothorax varies widely. Massive effusions at birth compromise venous return and are usually associated with pulmonary hypoplasia, persistent pulmonary hypertension, and/or nonimmune hydrops fetalis.7 None of these findings were evident in this case. Improved perinatal as well as postnatal outcomes are seen in preterm infants who were diagnosed and managed prenatally, like our case.8 Given that the lymphatic system operates under low pressure, it is possible that postnatal lung expansion prevented pleural fluid reaccumulation for approximately 3 to 4 weeks following the initial drainage. With reappearance of chyle, the infant was managed conservatively with indigenous nutritional modifications and continues to do well on multiple follow-up visits.SummaryChildren affected by primary, nonsyndromic congenital chylothorax without fetal hydrops have the potential for good outcomes if detected early and managed promptly.Feeding modifications play a key role in the nonpharmacological, nonsurgical management of congenital chylothorax, as children may respond well to conservative therapeutic options.In the absence of commercially available low-fat formulas, skimmed mother’s own milk can be easily prepared, including in resource-limited settings.American Board of Pediatrics Neonatal–Perinatal Content SpecificationUnderstand issues related to preterm birth.Recognize signs of acute and chronic perinatal asphyxia.Know common disorders of the chest wall, diaphragm, and pleura.Know the principles and applications of enteral nutrition.