When neonatologist Randy Grubbs, MD, first rigged up a model to show colleagues at Harris Methodist Fort Worth Hospital (HMFW) in Texas what bubble continuous positive airway pressure was all about, the initial response to his outdated, low-tech system was anything but positive. Listening as Grubbs extolled the benefits of the bubble CPAP technology he had used during his fellowship in neonatology, NICU staff nurse Vicki Hilburn, BSN, RN-C, was pretty skeptical.
"When Dr. Grubbs rigged up this antiquated-looking system for us to understand what bubble CPAP was all about, we all laughed," she acknowledged.
Rather than being offended by the initial response, Grubbs took the feedback in stride.
"Bubble CPAP is a simple system without a lot of bells and whistles, and that simplicity makes it look like you're going back 40 years in medicine," he noted. "Sometimes, however, simpler is better. I took a small group of clinicians with me to the NICU at NewYork-Presbyterian Hospital/Columbia University Medical Center in New York City. That trip got people on board with the idea, so we could move forward with the concept here at HMFW."
Vicki Malone, RN-C, NICU clinical coordinator, had a change of heart after observing the situation in New York.
"From my perspective, the best part of the New York trip was not the bubble CPAP itself, but the change in thinking we noticed in the clinicians caring for these babies," she said. "Bubble CPAP is minimally invasive, so we don't interfere with what the baby's body is doing to maintain health."
An Overview of Bubble CPAP
Traditional forms of CPAP use valves at the end of the expiratory tube to keep underdeveloped lungs open at the end of exhalation. Bubble CPAP, on the other hand, relies on a bottle of water to control the expiratory pressure. To maintain 5 cm of pressure, clinicians insert the tubing 5 cm into the bottle of water, regulating the air flow.
The flow of air out of the tubing sends vibrations to the baby's chest and serves to recruit more alveoli to increase the baby's functional residual capacity. Because the shaken air molecules move in and out of the lungs more readily, there is increased lung inflation and more of the lung tissue involved in the respiratory efforts.
"You can see, feel and hear the vibrations when you examine the baby, so we'd expect this would help loosen secretions, although that hasn't been demonstrated in the literature," Grubbs said.
The goal of bubble CPAP is to minimize the amount of time tiny babies spend on the ventilator, reducing the risk of chronic lung disease, one of the most common and debilitating outcomes for premature babies who have a very low birth weight.
"Although infant ventilators have become increasingly sophisticated over the past several years and are certainly necessary in many instances to save babies' lives, they remain one of the major factors associated with developing chronic lung disease, which in turn raises the risk of long -term problems such as higher susceptibility to and severity of respiratory infections and asthma, and neurologic and developmental setbacks," Grubbs explained.
A Culture Change
The decision to use bubble CPAP at HMFW to provide spontaneously breathing infants with the respiratory support they need was made after a yearlong analysis of clinical findings.
"We reviewed the medical research literature thoroughly and modeled our process after NewYork-Presbyterian Hospital/Columbia University Medical Center, which reports the lowest rate of chronic lung disease [in premature babies] in the world - 6 percent compared to the national average of 24-30 percent," Grubbs said.
After the New York trip, an interdisciplinary team started a planning process to introduce bubble CPAP at HMFW. To get started, team members had to tackle discrepancies in practice patterns.
"We have 16 physicians in our neonatal group, and that means we had 16 different ways of doing things in the past," Grubbs said. "We had to establish agreement on one way to deal with these babies. We now place these babies on bubble CPAP right in the delivery room and then monitor them closely. We had to answer key questions, including ÔIf the baby is not doing as well as we expect, when are we going to call it a CPAP failure and proceed to intubation and ventilator support?' Once we established those parameters, that consistency received rave reviews from the bedside staff."
Bubble CPAP became a reality in the NICU at HMFW in September 2007. Along with implementing bubble CPAP, the team espoused a change in focus.
"We saw the nurses at Columbia standing back and letting nature take its course, and that was difficult for us to accept in the beginning," Malone acknowledged. "That doesn't mean we're letting them lay there and work if they do need additional respiratory support, but we're giving them a chance to breathe on their own instead of putting them right on the ventilator."
The combination of bubble CPAP and the culture change has meant a more labor-intensive level of care for these tiny neonates, demanding careful, ongoing assessment and critical thinking.
"We maintain constant vigilance in assessing our babies on bubble CPAP and watching for signs of improvement or decline," Hilburn said. "It definitely demands more from us than ventilator care does, but it's so effective it's definitely worthwhile."
Bubble CPAP is a winner not only with clinicians, but with the baby's family members as well.
"Parents feel so much more comfortable with the bubble CPAP than the ventilator," Malone said. "There is a lot more hands-on freedom for them to hold and cuddle their babies. When a neonate is on a ventilator, we'll remind them, 'You have to be careful not to pull the tube out,' and that intimidates many parents. With the bubble CPAP system, we just pick the baby up and hand him over. Mom and Dad can bathe the baby. If they're in the unit while we're changing the mustache, they can see the baby's whole face, something that isn't possible with an infant [on a ventilator]."
NICU staff at HMFW encourages Kangaroo Care, an approach that supports skin-to-skin contact between the neonate and the parent. While this approach isn't always feasible for babies on a ventilator, infants on bubble CPAP are accessible for the early and close contact that promotes bonding.
"I think the bubble CPAP also has the benefit of being very parent-friendly," said Pam White, MSN, RN, CPNP, NICU clinical nurse educator. "If the nose prongs fall out while the baby is being held, they easily slip back in, unlike when a baby is accidentally extubated if the ventilator tube is dislodged."
Since bubble CPAP was instituted in the NCU, there has been a doubling in CPAP hours along with a steady decrease in ventilator hours. From a baseline of 13,000 ventilator hours in August 2007, the unit dropped quickly to 6,000 hours a month and now is averaging only 3,000 hours a month.
By combining a culture change that embraces less-invasive measures and implementing bubble CPAP, NICU clinicians have created an environment conducive to improvement in other patient outcomes.
"We see less use of central lines, fewer interventions to maintain blood pressure, fewer ventilator days and less trauma to the airway," Grubbs said. "Hopefully, those changes will lead to fewer central line infections and a reduction in ventilator-associated pneumonias. And we know from the literature intraventricular hemorrhage and necrotizing enterocolitis seem to be less common in babies on bubble CPAP, so we're hoping to see those trends as well."
Long part of the Vermont Oxford Network, a voluntary collaboration that maintains a database about medical care of newborns, HMFW staff continues to collect information that will identify the impact of bubble CPAP on chronic lung disease and other complications of prematurity.
"Historically with tiny babies, treatment priorities have been to assume they're sick and implement invasive therapies," Grubbs said. "Now we're assuming these neonates are healthy, putting them on bubble CPAP in the delivery room and watching to see how their bodies respond. It's a very simple approach, but I think it will ultimately become the best practice for NICUs nationwide when it comes to improving the lung development of babies born prematurely. The goal is to keep them as healthy as possible by minimizing invasive measures that can lead to complications."
Sandy Keefe is a frequent contributor to ADVANCE.