This ventilation technology for premature babies is also groundbreaking for adults

When Sabina Checketts holds her hand a certain way, the tiny scar on the back of it looks like a rocket ship. Checketts got the scar during the first few days of her life, after she was born at 28 weeks — 12 weeks prematurely. Her rocket ship scar, and a few other small ones, are marks left by lines inserted into her tiny, frail body to keep her alive.

“To me they’re badges of honor,” Checketts says, “because I survived.”

Thirty-three years after her premature birth, Checketts now works as a neonatal doctor. Today, she uses vastly improved technologies and techniques to create better outcomes for other premature babies — and to give more hope to their parents.

As vulnerable premature babies fight to stay alive, one of the most critical issues is something most people never think twice about: breathing. A pivotal advance in neonatal medicine, and one that has a major impact in adult critical care, has been the development of better ventilators.

The ventilator that helped Checketts survive was a far cry from what she sees today when she treats premature babies. One new ventilation technique is called Neurally Adjusted Ventilatory Assist (NAVA), developed by Getinge, a global leader in intensive-care technology for both infants and adults.

Before NAVA, ventilation technology had advanced to the point that a flow sensor at the breathing tube measured when a baby was trying to breathe in, and the ventilator supplied a breath. But there was lag time, resulting in the ventilator sometimes not supplying air and oxygen when the lungs called for it, or forcing air into frail lungs that were not ready for it — a problem amplified by premature babies’ tendency to take short, rapid, and uneven breaths.

“NAVA is a way to do a little better job,” says Sherry Courtney, an Arkansas-based director of clinical research in neonatology, who has worked with premature babies since the 1980s. “The diaphragm is a muscle. When it contracts, we’re going to breathe. When it relaxes, we’re going to exhale. So NAVA senses the breathing using a catheter that goes down into the stomach and rests close to the diaphragm.”

Electrodes on the catheter sense contractions in the diaphragm, resulting in an almost instantaneous signal that the patient wants to breathe. Synchronously, the ventilator supplies air. And when the electrodes sense the end of diaphragmatic contractions, the ventilator allows exhalation.

“NAVA just provides a little support, depending on the breath. The patient can be breathing as the patient wishes. Deep breaths, shallow breaths, long breaths, short breaths, bigger volumes, smaller volumes. That’s the way people breathe,” says Courtney. “And NAVA may allow all of that to happen, along with making sure everything is synchronized to the pattern of the breathing.”

Courtney says she’s observed many babies who switch to a NAVA-enabled ventilator almost immediately become more comfortable and less irritable. Their oxygen needs decrease, as do pressure and volume requirements. Babies can be more restful and concentrate energy on the single most important thing they can do during their premature stage — grow.

What’s not as well known in the U.S. is that NAVA is also approved for adults, and the features that make the technique successful for neonates translate well to grown-up patients. Adults on ventilators generally start with a functioning diaphragm, but it will become weaker quickly if a ventilator breathes for them for too long. Getinge Medical Director Miray Kärnekull says that advanced ventilator technologies like NAVA are used regularly in adult patients in Europe to keep patients’ diaphragm muscles active.

“With conventional ventilation modes there is no monitoring of the diaphragm activity, so you have no idea actually what’s happening there,” Kärnekull says. Driving too much air into the lungs, for instance, suppresses the respiratory drive and weakens the diaphragm. This can cause problems when it’s time to wean a patient off the ventilator.

In addition to helping maintain the diaphragm’s tone, the synchrony of a NAVA ventilator means patients don’t fight against the ventilator. To prevent that, adults usually need to be heavily sedated. With NAVA, doctors can reduce sedatives, allowing for earlier weaning with fewer complications.

“It’s really a groundbreaking technology,” says Kärnekull. “NAVA gives the clinician a way to personalize not only the ventilation, but also the weaning process for adult patients. And in a recent trial, results showed that patients with acute respiratory failure on NAVA spent significantly less time on the ventilator and experienced less extubation failure compared to conventional, lung-protective mechanical ventilation.”

NAVA technology is only one way ventilators are improving. Advances in the ventilators themselves, and the software that powers them, have allowed for more personalization. Critical care ventilators now can be fine-tuned to each patient’s specific needs. But some medical emergencies are too complicated and acute for even the most sophisticated ventilators. For those instances, another new development can help support the ventilation. This technique, called Extracorporeal Life Support (ECLS), simulates the function of lungs or a heart that’s ceased working.

“Basically, we take blood out of one of the big veins in the body,” says David A. Kaufman, MD, Pulmonary & Critical Care Medicine at NYU School of Medicine. “We run it through a chamber where we are able to extract the carbon dioxide and put in a high concentration of oxygen. Then, that blood is injected back into another vein.”

Invented in the 1960s to facilitate cardiac surgeries with cardiopulmonary bypass, extracorporeal techniques and technologies have been refined to the point that they’re used increasingly worldwide. In response, Getinge, a leading manufacturer of equipment used in extracorporeal support, has increased investment and production of components to meet demands.

ECLS is primarily a way to buy time and keep the blood oxygenated without damaging lungs in the most critical situations — like multi-organ failure — while doctors figure out how to save the patient. The technique has potential in the case of trauma, while a patient awaits organ donations, or in the treatment of acute respiratory distress syndrome (ARDS), when a ventilator on its own may not be able to support clinical targets of both gas exchange and lung protection.

These high-tech medical procedures are a few of the developments changing the way that doctors practice intensive-care medicine, and the promising advances have allowed physicians like Checketts to celebrate even more success stories. Checketts decided to become a doctor at an early age, when her mother routinely pointed out a man walking down the street on his way to the hospital and said: “That’s the doctor who saved your life.” That experience motivates her to be a positive force in the families of the babies she treats.

“When I talk to parents about the fact that I was premature, there’s always a sense of surprise, I think a little bit even shock, you know. ‘Oh, oh, and you’re a doctor,’” Checketts says. “I think it’s a nice way to say to them that prematurity shouldn’t be a limit on what a child can do.”

“I mean, the advances we’ve made in even just the last 10, 15, 20 years mean the outcomes are much better than they used to be,” she continues. “And seeing me, who developed before that, as a newborn doctor, I give them a sense of hope and possibility, I think.”

^[*] In the United States, the SERVO-U ventilator system is intended for respiratory support, monitoring, and treatment of neonatal, pediatric, and adult patients. NAVA monitoring is used to improve synchrony between the ventilator system and patient when the electrical signal from the brain to the diaphragm is active. NAVA is for use on all patients with no contraindication for insertion/exchange of a nasogastric tube.