Gastric Venting in the NICU

Have you seen a shift in the approach to ventilating neonates in the past few years? I certainly have. The shift to non-invasive positive pressure ventilation (NIPPV), such as bubble CPAP (continuous positive airway pressure) or NIV-NAVA (neurally-adjusted ventilatory assist) is the new era of respiratory support in the NICU.

Previously, it was commonplace for premature infants to receive a breathing tube and they were dependent on a ventilator for weeks to months. As a NICU nurse, I was very comfortable caring for an infant with a breathing tube. It was actually rare to have a baby without one. Nowadays, I have to walk the entire unit and still may not find a single patient with an artificial airway. Times have clearly changed – and for the betterment of the fragile lungs of these premature infants! However, with the different approach to ventilation, the unintentional passage of air into the belly through NIPPV airflow is now something that should be considered when caring for these patients.

“The problem with noninvasive positive pressure is that there is not one, but two primary internal pathways for gas to flow: the trachea and the esophagus."

The anatomical challenge to this approach to ventilation is the connectivity between the trachea and esophagus. The goal is for the air to enter and ventilate the lungs; however, there is going to be some amount of air migrating into the stomach. This can create a varying range of issues in these patients especially if it then continues to travel into the intestines. The term being used to describe this outcome is “CPAP Belly”.

“With rampant use of non-invasive respiratory support in extreme preterm infants, the occurrence of severe CPAP belly syndrome now extends to include clinical scenario mimicking a “necrotizing enterocolitis (NEC) scare”.

Even the most subtle of change in assessment in the NICU can prove detrimental in very little time. NEC, or even just the symptoms similar to that of a NEC infection, is a very scary incident in the neonatal patient. When these symptoms are present “ceasing feeds and performing abdominal X-rays to exclude pneumatosis intestinalis are all justified.” This of course can delay progress in the neonate’s journey as they undergo additional diagnostic tests and imaging to rule out any serious, life-threatening conditions. Anyone who has cared for a premature infant in the NICU knows the long road of meeting milestones for growth, temperature regulation, feeding toleration and advancement, to name a few. A NEC scare can considerably delay this progress, leading to extending the length of stay and an increased cost of providing ongoing medical care.  

Because of this, many clinical practice guidelines have moved to the standard of unclamping or opening the feeding tube to relieve or vent excess air from the stomach between feedings of those receiving NIPPV. Some guidelines I’ve seen are more prescriptive than others:

• A few specify a timeframe after completion of the feeding to intervene with unclamping, such as waiting until 30 minutes after the feeding.
• Others may state a designated amount of time the tube is to be vented between feedings.
• In their journal article titled, The Nursing Care of the Infant Receiving Bubble CPAP Therapy (2008), Bonner and Mainous note that “It may be necessary to aspirate air from the OG tube before feedings to decrease the gastric distention. Also, if an infant is receiving continuous feedings, routine aspiration of gastric air is recommended”.

This venting of air is typically achieved with the feeding tube already dwelled for feeding, versus instilling a second tube designated for venting. However, some practices include introducing a second tube. Use of the largest appropriate feeding tube lumen may also help facilitate effective venting of gastric air.

There continues to be much opportunity for learning and better understanding any unintended effects of NIPPV on the neonate. Through ongoing clinical application and research, we can tailor the approach to caring for these vulnerable patients.

I would love to hear about your current clinical practices and approaches to gastric venting for NICU patients on non-invasive ventilation. Please reach out and share your facility’s practices and outcomes!

References

1. Kim, J. “Blowing Up” the CPAP Belly Myth. Medela. 2018. Retrieved from: https://www.medela.us/breastfeeding-professionals/blog/blowing-up-the-cpap-belly-myth
2. Priyadarshi, A., Hinder, M., Badawi, N., Luig, M., & Tracy, M. (2020). Continuous Positive Airway Pressure Belly Syndrome: Challenges of a Changing Paradigm. International Journal Of Clinical Pediatrics, 9(1), 9-15.
3. Bonner, Krista M. RNC, MSN, NNP1; Mainous, Rosalie O. RNC, PhD, NNP2. The Nursing Care of the Infant Receiving Bubble CPAP Therapy. Advances in Neonatal Care 8(2):p 78-95, April 2008. | DOI: 10.1097/01.ANC.0000317256.76201.72