03/01/07

MAQUET Critical Care, Bridgewater, NJ, has received FDA 510(k) clearance for its NAVA (Neurally Adjusted Ventilatory Assist) technology for optional use with the company’s SERVO-i ventilator. The SERVO-i ventilator with NAVA option is intended for treatment and monitoring of all patients, neonatal, pediatric, and adults who require mechanical ventilation.

The NAVA technology detects respiratory signals sent from the brain to the diaphragm (in cases where the brain-to-diaphragm electrical signal is intact) and transmits those signals to the SERVO-i ventilator. By enabling the respiratory signals from the patient’s brain to control ventilator function, NAVA technology results in unprecedented coordination between diaphragmatic activation and ventilatory support throughout the breathing cycle. 

To initiate assistance and regulate their level of ventilatory support, conventional mechanical ventilators monitor airway pressure, flow or volume—variables that require greater patient effort with increasing ventilatory dysfunction. By contrast, NAVA senses the electrical activity of the diaphragm and regulates breath delivery from that signal known as Edi.

Originating in the brain’s respiratory control center, these signals travel through the phrenic nerve to the diaphragm. NAVA uses a series of microelectrodes which are embedded in a specially designed naso-gastric tube to detect the electrical activity that excites the diaphragm, and this signal is then amplified and transmitted to the SERVO-i ventilator. With ventilator and diaphragm both responding to the same neural signal, NAVA represents a form of monitoring and assisted ventilation in which the patient’s respiratory center controls the mechanical support provided throughout each breath.

In its 510(k) clearance statement, it is stated that the NAVA option will improve synchrony between the ventilator and patients with no contraindication for insertion/exchange of a naso-gastric tube. The Edi signal is a useful indicator for monitoring weaning as it is also an indicator of the respiratory drive which gives additional clinical information about the patient’s respiratory condition.

“We believe that NAVA technology could be one of the most significant advances in critical care since mechanical ventilators were introduced more than 30 years ago,” says Doug Smith, vice president of MAQUET Critical Care. “NAVA enables patients to be synchronous with their ventilatory support based on their own neural respiratory output. As a result, patients can now receive their necessary level of ventilatory support that the patient can control and adjust as their needs demand. In clinical studies by Christer Sinderby, PhD, NAVA has shown to increase patient comfort, while ventilating at lower pressures.”