By Dr. Namrata Todurkar
Of the many conditions that premature infants experience in NICU, GERD is probably the most intriguing to both parents and health care providers. This is because the symptoms are non-specific, diagnosis is not easy and treatment is not straight forward. Reflux is often blamed for issues like recurrent desaturations and apneas without solid evidence. Moreover, knowing about GERD is important because many NICU graduates continue to be diagnosed and treated even after they are discharged. This blog will discuss why reflux affects preemies, its common symptoms, and potential complications and different treatments that may help.
Gastroesophageal reflux (GER) is defined as the retrograde passage of stomach contents into the esophagus food pipe), and when ‘troublesome symptoms’ persist due to these events, it is called gastroesophageal reflux disease (GERD). GER is a normal occurrence in neonates with 2–3 episodes of reflux per hour, and GERD is a common diagnosis, affecting 1 in 10 infants admitted to the NICU. Research shows that preemies with GER have longer hospital stays and higher health care costs. Although most babies grow out of reflux, some feeding modifications may be needed in the meantime.
What Causes Preemie Reflux?
When the contents of the stomach (high pressure area) move back up through the esophagus (low pressure area) because of a relaxed lower esophageal sphincter (LES), it manifests as a reflux or a spit-up. This circular ring of muscle is located at the lower end of the food pipe. It normally opens to allow food to enter the stomach, but then tightens and closes to prevent stomach contents from going the other way. GERD is a disease in which the LES does not close completely or opens at the wrong time. As a result, food and stomach acid can come back up and be vomited, which can cause pain from irritation of the esophagus. Triggers of LES relaxation include swallowing, stomach distention, straining, respiratory distress, and possibly caffeine therapy.
Contributory factors unique to preemies:
Physical immaturity: The food pipe joins the stomach in a way which is conducive to reflux. This gets better with time.
Feeding pattern: Premature infants tend to receive a relatively large volume of liquid feedings while lying on their back, thus allowing milk to easily reflux back into the esophagus when the LES relaxes. Preterm infants who receive tube feedings may have increased episodes of GER due to the incomplete closure of the LES secondary to the presence of a feeding tube.
Specific Risk Factors for GERD
Infants with bronchopulmonary dysplasia (BPD) have increased risk of GER events secondary to increased respiratory effort and transient increase in intra-abdominal pressure due to coughing, airflow obstruction, and crying.
Brain pathologies such as intraventricular hemorrhage (IVH), and hypoxic-ischemic encephalopathy are some of the common risk factors causing dysregulation of aerodigestive reflexes.
Reflux in premature infants is known to cause many symptoms, including:
Significant irritability and crying, being very unsettled
Choking, gagging, or coughing with feeds
Change in vital signs (heart rate, respiratory rate, oxygen saturation variations evident on the NICU monitor)
Signs of discomfort when feeding, like back arching or grimacing
Frequent vomiting
That said, studies have not shown a direct link between these nonspecific symptoms and GER. For example: a recent study from Nationwide Children’s Hospital Ohio, observed more than 500 infants in the NICU and found that less than 10% of the arching and irritability events happened after acid reflux. The researchers learned that 92% of arching and irritability events had other causes. In addition to the above symptoms, GER may lead to various complications including failure to thrive, esophagitis (inflammation of the esophagus), and lung aspiration.
Diagnosis
Most cases of GER in premature infants are diagnosed clinically, meaning the healthcare provider will assess the baby for typical symptoms of GER and also rule out alternative reasons and diagnoses. Less commonly, diagnostic tests—esophageal pH, contrast fluoroscopy and multiple intraluminal impedance monitoring—are used. These tests can be technically difficult to perform, and the results can be challenging to interpret.
Treatment of Reflux in Preemies
About 40% to 60% of normal 0- to 4-month-old infants regurgitate some amount of their feedings. While it can be difficult to watch your preemie become so unsettled by reflux symptoms, it can be comforting to know that most babies outgrow the condition as they mature. So, if your baby is spitting up a lot but seems happy and is growing, then you can put your mind at ease—this is normal and should pass.
Positioning:
After feeding, keeping your baby in an upright position or in a left-side-down position can be effective, but only when your baby is awake and being supervised. When it comes to sleeping, your baby needs to be on their back whether they have reflux or not. Furthermore, according to the American Academy of Pediatrics, devices used to elevate the head of a baby's crib (e.g., wedges) should not be used, as they increase the risk of the baby rolling into a position that may cause breathing difficulty.
Milk and Formula:
Sometimes, reflux may be related to a baby not tolerating certain proteins in their milk. For example: something in the formula may be triggering poor digestion or irritating your baby. The medical team may advise a special formula in this case.
Feeding Adjustments
Giving smaller-volume feedings more frequently may be helpful.
Reflux Medications :
Your baby's healthcare provider may prescribe an acid-suppressing medication if conservative management with smaller, more frequent feeds are not helpful and symptoms are significant. However, acid-suppressing medications may not reduce symptoms but may increase the risk of developing very serious complications, including sepsis, pneumonia, urinary tract infections and necrotizing enterocolitis (NEC). Refluxed gastric contents are less acidic in infants due to their unique diet that consists of relatively alkaline milk. The majority of reflux episodes have a pH between 4 and 7 (weakly acidic). This is a possible explanation for the lack of effectiveness of acid-suppression therapy in this population. Surgeries like ‘Fundoplication’ are rarely recommended.
Summary:
In preterm infants, GERD continues to be misunderstood, over-diagnosed, and over-treated. Diagnosis and management considerations for GER and GERD in the NICU infant can be challenging for the treating team and family alike. Emphasis must first be placed on conservative management and identifying red flags. Minimizing the use and duration of acid-suppressive therapies is appropriate while weighing risks and benefits.
Dr. Namrata Todurkar, MBBS, MD (Pediatrics), DNB (Pediatrics). Fellowship in Neonatology from National Neonatology Forum India. Fellow in Neonatal-Perinatal Medicine at the University of British Columbia. Areas of interest: Neonatal nutrition, Fluid and Electrolyte Management, Inborn Errors, Neurodevelopmental follow-up of preterm infants. Dr. Todurkar is a volunteer blogger at CPBF.