Ventilation system for ‘preemies’ mimics brain-to-lungs respiratory response

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A trial of a new ventilation system for premature babies who are in respiratory distress at Sunnybrook is showing promising early results by acting as a successful artificial respiratory muscle.

The Sunnybrook pilot trial utilizes a new approach to mechanical ventilation, based on neural respiratory output. Premature infants are born with underdeveloped lungs and often require mechanical ventilation to support their breathing as their lungs mature and grow. One of the biggest challenges in helping any patient breathe is ensuring that the ventilator works in sync with the patient’s own breathing.

During normal breathing, respiratory signals that originate from the brain pass along the phrenic nerve to the diaphragm, the major muscle of breathing, which then contracts and air enters the lungs. This new mode of ventilation is able to read the brain’s signals to the diaphragm, which helps the ventilator to better breathe simultaneously with the infant.

“It’s like being a step closer to the infant’s brain. The technology captures the electrical activity of the diaphragm by using a special feeding tube with electrodes and feeds the signals to the ventilator to assist the baby’s breathing,” says Dr. Jennifer Beck, head of the Sunnybrook research team and one of the study’s co-investigators.

Developed at St. Michael’s Hospital in Toronto by Dr. Christer Sinderby, and also piloted on adults at that hospital, this is the first time that the technology has been used with premature infants. NAVA, or Neurally Adjusted Ventilatory Assist, is currently being evaluated on 14 babies with funding from the National Institutes of Health.

Premature infants in the neonatal intensive care unit who are recovering from respiratory illness are eligible for the trial. The ventilation system does not require an additional feeding tube as it works by placing sensors on feeding tubes that are already in place.

“The new system is designed to be as gentle as possible to the preemies, by supporting their breathing with the goal of minimizing damage to their lungs. This is especially important as many premature infants are on ventilators for a long time,” says Maureen Reilly, respiratory therapist.

Dr. Jennifer Beck explains that “NAVA technology matches the timing of the delivered breath with the beginning and the end of the patient’s neural respiratory effort. Secondly, the assist level adapts to changes in neural respiratory drive.” For the first time, the baby’s own neural breathing cycle and volume of air will be controlled by the infants themselves.

Other investigators involved in the pilot trial are Dr. Michael Dunn, neonatologist at Sunnybrook, Dr. Arthur Slutsky, and Dr. Christer Sinderby from St. Michael’s hospital.

The Neonatal Intensive Care Unit (NICU) at Sunnybrook is a leader in the development of an individualized, family-centered approach to the care of newborns. Each year, the NICU cares for over 1,000 babies, most of them premature. Sunnybrook delivers approximately 4,000 babies each year and of these births, 1 in 4 of them is considered to be “high-risk.” The organization is one of only two hospitals in the GTA serving high-risk mothers and newborns with specialized care in the Neonatal Intensive Care Unit.