From the Guidelines
Neurally Adjusted Ventilatory Assist (NAVA) ventilation is a mode of mechanical ventilation that delivers pressure proportional to the electrical activity of the diaphragm, improving patient-ventilator interaction and synchrony. This mode of ventilation uses a specialized nasogastric tube with electrodes to capture the electrical signal from the diaphragm, providing ventilatory support that is proportional to the patient's neural respiratory drive 1. The key characteristics of NAVA ventilation include:
- Improved patient-ventilator synchrony
- Reduced work of breathing
- Decreased sedation requirements
- Potentially shorter ventilation duration NAVA ventilation is particularly beneficial for patients with difficult ventilation scenarios, such as those with COPD, asthma, or neuromuscular disorders. Implementation of NAVA ventilation requires specific equipment, including a Servo ventilator with NAVA capability, and proper placement of the specialized catheter to detect diaphragmatic electrical activity 1. While NAVA ventilation may be more complex to set up than conventional modes, it represents an important advancement in mechanical ventilation by creating a more physiologic breathing pattern that responds directly to the patient's respiratory center signals.
Some of the key benefits of NAVA ventilation include:
- Minimizing or suppressing asynchrony, which is associated with prolonged duration of mechanical ventilation and increased morbidity and mortality 1
- Improving sleep quality, although the evidence is mixed 1
- Providing a more personalized breathing pattern that adapts to the patient's changing respiratory demands Overall, NAVA ventilation is a valuable tool in the management of mechanically ventilated patients, particularly those with complex respiratory needs.
From the Research
Definition and Mechanism of NAVA Ventilation
- Neurally Adjusted Ventilatory Assist (NAVA) ventilation is a mode of mechanical ventilation that uses the electrical activity of the diaphragm (EA(di)) to trigger and adjust ventilatory assist 2.
- The implementation of NAVA requires the introduction of a catheter to measure the EA(di), which is used to determine the amplitude of the ventilator assist on a breath-to-breath basis 2.
- NAVA relies on the EA(di) signal to integrate the ventilator into the neuro-ventilatory coupling, allowing for more precise control of ventilation and improved patient-ventilator synchrony 2, 3.
Comparison with Other Ventilation Modes
- NAVA has been compared to other modes of ventilation, such as pressure support ventilation (PSV) and variable pressure support ventilation (VPSV) 4, 5, 6.
- Studies have shown that NAVA can improve patient-ventilator synchrony and reduce the risk of respiratory over-assistance compared to PSV 2, 5.
- However, some studies have found that VPSV can reduce the variability of tidal volume and pressure support compared to NAVA 4.
Clinical Applications and Benefits
- NAVA has been used in various clinical settings, including critically ill patients and patients with chronic obstructive pulmonary disease (COPD) 2, 6.
- The use of NAVA has been shown to improve patient-ventilator synchrony, reduce the need for sedation, and promote more efficient weaning from mechanical ventilation 2, 5, 6.
- NAVA may be particularly beneficial for patients with major patient-ventilator asynchrony, such as those with COPD or small children 2.