This article will discuss the invasive and noninvasive therapy options available for NICU clinicians, including bCPAP, HFO, NIV and invasive ventilation—and the factors these clinicians must weigh when initializing therapy or when it becomes necessary to escalate respiratory support.
By Greg Thompson
Respiratory clinicians in the neonatal intensive care unit (NICU) take care of the most vulnerable among us, choosing therapies that include bubble CPAP, high-flow oxygen therapy, NIV, and invasive ventilation. Sarah Handley, MD, associate medical director of the Seattle Children’s NICU has also used low-flow oxygen, but not often, and only for babies who need much less support and/or pressure.
The Neonatal Respiratory Support Technologies team, based in Seattle Children’s Research Institute, has provided Handley and colleagues with an invention called the Seattle Children’s Positive Airway Pressure (Seattle-PAP) device. The equipment (later acquired by Dräger) improves on Bubble CPAP.
Seattle Children’s Level IV facility uses conventional ventilation, plus jet ventilation, high frequency oscillatory ventilation, NIV, and invasive ventilation. NICU clinicians consider oxygenation, lung stress, pulmonary distress, and conditions such as bronchopulmonary dysplasia when deciding on the right time to escalate or de-escalate these types of therapies.
All babies at Seattle Children’s transfer in and therefore tend to be older than brand new babies. “We get premature babies as well but not as often, which does affect our use of respiratory support as far as a preemie baby versus a term baby who has been chronically ill,” Handley said. “We try to use CPAP on our babies that are more premature—less than 32 weeks—and it might not necessarily be bubble CPAP. It might be CPAP from the Dräger but usually it’s bubble.”
Handley and her team try hard to keep babies on CPAP up to 32 weeks. “We do that because studies have shown that premature babies who receive bubble CPAP have lung growth during that time,” she said. “Then we monitor these babies to make sure that they are able to graduate to the high-flow. We also have RAM, which has been wonderful for our older babies when they are able to wean on their bubble CPAP, and come down on their oxygen requirement and distention pressure.”
If the work of breathing (WOB) gets much greater after weaning, Handley is adamant, “We may then need to hold off and go slower. As those babies get older and are term, or even post-term, bubble CPAP is still very good—but the interface is difficult for some older babies. They really don’t tolerate it well so we will go with RAM CPAP. We will keep those babies on RAM CPAP until they show us again that they’re able to wean on the oxygen, and they are able to come down on their pressure support.”
Gestational age, history, and lab values are key factors, in addition to chest X-rays and WOB. “We look to see if they have retraction, which is really sucking in where we can see their rib cage a little more distinctly,” said Chelsea Brubaker, RRT-NPS, staff respiratory therapist at Lehigh Valley Reilly Children’s Hospital, Allentown, Pa. “We listen for grunting that signifies that they’re working harder and trying to keep their airway open. We look at blood gas results, carbon dioxide levels, and pH in the bloodstream to see how well they’re ventilating. We watch oxygen saturations to see if we need to adjust our support to help them keep their lungs open a little more and get that oxygen requirement down if they are in high oxygen requirements.”
Intubation/Extubation
When a premature infant girl (born at 23 weeks) arrived at Seattle Children’s NICU two weeks after birth, the child presented with an isolated perforation in the intestine—not uncommon for tiny preemies. The infant arrived on CPAP and Handley had to intubate her for surgery. After surgery she was extubated to CPAP (plus 9) after proper weaning on invasive ventilation.
“Over several weeks, she was able to grow and we slowly weaned that CPAP,” said Handley, who also serves as co-director of Seattle Children’s bronchopulmonary dysplasia program. “We watched her carbon dioxide, making sure that her WOB was okay, making sure she’s gaining weight and not spending all her time working hard to breathe. We counted the days until she reached 32 weeks so that we could transfer her from bubble CPAP to a RAM CPAP—or a high-flow. That is a usual progression for our tinier babies.”
Sicker babies, especially those with chronic lung disease, will often be extubated and moved to CPAP—many times at a setting greater than 10. “The only way for us to do that right now is to go to the Dräger Ventilator and do CPAP off of the Dräger Ventilator because we can only do Bubble CPAP up to 10,” Handley said. “We try so hard to get them extubated, because they’ve been intubated for such a long time, and they can get tracheal injuries—specifically distended tracheas because of the pressure, or tracheal stenosis from ongoing friction in the airway.”
Once babies are moved to CPAP, therapists watch them carefully for signs of thriving, such as interacting with caregivers and enjoying play. “If they’re not meeting those standards on CPAP, we will have to re-intubate those babies because it’s so important for those babies to grow,” Handley lamented. “As RT readers know, linear growth is lung growth. If we are not able to get those kiddos to grow lengthwise, then their lung health takes much longer to improve.
“We often use the CPAP for quite a long time on our chronic babies because their lung injury has occurred over several months, and we expect their lungs to take several months to slowly heal,” Handley said. “We move very slowly with these infants. We will keep them on for weeks at a certain CPAP level and tentatively go down. The majority make it to a point where we are able to wean the CPAP.”
The Delivery Room
Before a baby arrives at a Level IV facility such as Seattle Children’s, evaluations for possible respiratory interventions begin immediately. “It starts in the delivery room,” confirmed Keith Hirst, MS, RRT-ACCS, RRT-NPS, AE-C, FAARC, associate professor and program director at Boston-based Massachusetts College of Pharmacy and Health Sciences (MCPHS).
Gestational age, respiratory rate/pattern, heart rate, color, and APGAR scores are all taken into account. “That really starts off whether you’re going to initiate with positive pressure, and if the baby responds or doesn’t respond,” Hirst said. “Do you need to put in a breathing tube? Or if they are responding, can you get by with NIV like bubble CPAP? Or can you use some other low level of oxygen therapy such as nasal cannula or even room air?”
Hirst estimated that Bubble CPAP is the dominant mode in use right now, primarily because, “A lot of studies have shown that bubble CPAP has reduced chronic lung disease and bronchopulmonary dysplasia. It’s being used much more aggressively and early on for neonates with respiratory distress.”
For RTs who are not entirely convinced about the efficacy of bubble CPAP, Hadley added: “I would like to reassure those respiratory therapists that bubble CPAP is a wonderful tool and it is very safe. It is able to distribute that end-diastolic pressure because of the interface with the water, and it decreases the pressure that babies are trying to breathe against. Because if pressure gets too high, they could get a pneumothorax. Bubble CPAP is a wonderful and safe way to ventilate these babies if they have had decent lung growth or healing while intubated, and in the position to be adequately supported by bubble CPAP.”
Ultimately, the decision-making process is honed from years of experience, and Hirst recalls the case of a particular infant who was born premature and initially put on noninvasive ventilation. “After a little bit, the baby began to fail,” Hirst recalled. “We intubated him, gave him surfactant, and was able to quickly extubate him but he continued to have respiratory distress despite the surfactant. We ended up having to intubate him and provide positive pressure and invasive ventilation. The baby actually ended up developing a pneumothorax—basically the lung collapsed.”
From there, the team made the decision to move to high frequency ventilation to help preserve the other lung. “That baby spent a fair amount of time on high frequency ventilation before we were able to successfully wean him back to conventional ventilation, and finally to noninvasive, and then finally to high flow and then to low flow nasal cannula. During the time, a lot of it was based on how the baby was looking, his blood gases, age, and X-rays. These were all factors as we moved through the process.”
Decision-making in the NICU
The factors that NICU clinicians weigh when initializing therapy and escalating to new therapy are overwhelmingly governed by research, literature, and current best practices. While a standardized approach lends clarity, Chelsea Brubaker is quick to point out that every case is different.
“We follow research and literature to develop protocols, but there will always be a degree of past experiences amongst each provider that subconsciously plays into decision-making,” said Brubaker. “Every patient, no matter how similar in background, can follow a very different course when it comes to escalation of therapy.”
Among clinicians, there is not always universal agreement on what type of support is best to use in the NICU. The key is cooperation, and Handley at Seattle Children’s is keen to ask for opinions among her experienced RTs. “Our respiratory therapists are some of my best partners in working for these kiddos,” Handley said. “I can’t tell you how many times I’ve asked my RTs, ‘What do you think?’ They watch these kids all the time and are monitoring their respiratory health all the time—more often than me—and they are vital to helping us do the best that we can for our patients.”
RT
Greg Thompson is a contributing writer to RT. For more information, contact [email protected].
