Approach to complications of prematurity (late): Clinical sciences

Preterm birth before 37 weeks of gestation can result in various complications that increase an infant’s morbidity and mortality. These complications are most common among patients who are born before 32 weeks of gestation or those with very low birth weight under 1500 grams. Late complications of prematurity can develop after the first month of life, and because they don’t typically cause acute or obvious signs and symptoms, many are identified through screening.

Now, if a pediatric patient presents with a chief concern suggesting a late complication of prematurity, first obtain a focused history and physical examination. Then, review your findings to determine if your patient requires further evaluation.

Let’s start by assessing your patient’s oxygen requirement. If your patient required supplemental oxygen for 28 days or more, consider bronchopulmonary dysplasia, or BPD. History will reveal an infant born before 32 weeks of gestation. They may have had a patent ductus arteriosus, required mechanical ventilation, or had prolonged exposure to hyperoxia. The exam might reveal chest retractions and audible pulmonary rales. And when attempting to wean your patient’s supplemental oxygen, they will usually become hypoxemic and tachypneic within 60 minutes.

Even though BPD is a clinical diagnosis, you can consider ordering a chest X-ray to support the diagnosis, determine disease severity, and identify complications. Typically, the chest X-ray will reveal diffuse hazy opacifications and hyperinflation, with or without cystic lucencies. This combination of clinical and imaging findings confirms your diagnosis of bronchopulmonary dysplasia.

Okay, here’s your first clinical pearl! In severe cases of BPD, disrupted pulmonary vascular development leads to increased pulmonary vascular resistance and ultimately pulmonary hypertension. Over time, the right ventricle hypertrophies in order to maintain cardiac output. These patients can experience pulmonary hypertensive crises, during which an acute increase in pulmonary arterial pressure overwhelms the right ventricle and causes right-sided heart failure.

Okay, you’ll also assess your patient for signs and symptoms of anemia. Premature infants are physiologically predisposed to anemia, due to limited iron stores, impaired erythropoietin production, and a short fetal red blood cell lifespan. Newborns with anemia may have poor weight gain, apneic episodes, or a history of frequent lab draws. Keep in mind that some patients are asymptomatic, and the anemia might be discovered as an incidental lab finding. On physical exam, your patient might be hypoxemic, tachypneic, or tachycardic; and you’ll often detect pallor, especially on the conjunctivae and the palms of the hands and soles of the feet.

With these signs and symptoms, consider anemia of prematurity. To confirm the diagnosis, obtain hemoglobin levels, a hematocrit, and a reticulocyte count. If the hemoglobin and hematocrit are below reference range for age, and the reticulocyte count is low, diagnose anemia of prematurity.

Next, assess the need to screen for periventricular leukomalacia, or PVL. Since PVL is caused by an ischemic injury to the premature brain, these patients may have had a previous episode of hypoxemia or hypotension, or they may have been diagnosed with intraventricular hemorrhage, sepsis, or necrotizing enterocolitis. The physical exam may reveal an uncoordinated suck-swallow, increased muscle tone, or spastic diplegia. With these findings, consider PVL and order a cranial ultrasound. If it shows characteristic white matter injury, with or without cysts, diagnose PVL.

Now here’s a clinical pearl! PVL is often asymptomatic during the first weeks or months of life, so to identify it, you’ll need to perform routine screening with cranial ultrasound. For all infants with risk factors, such as a gestational age of 30 weeks of gestation or less, order the first ultrasound within the first 7 days of life, then again at 4 to 6 weeks of life, and at least once more before your patient is discharged from the hospital.