Let the Baby Drive: Understanding NAVA Beyond the Basics

There’s something special about the moment a ventilator finally starts to breathe with a baby instead of against them. In those moments, the ventilator isn’t controlling the rhythm — the baby is. That’s the philosophy behind NAVA, or Neurally Adjusted Ventilatory Assist — a technology that reads the baby’s own diaphragm signal and responds breath by breath.

NAVA isn’t a mode we reach because it’s “next” on the list. We use it because it’s what the baby needs — whether that’s a 24-week preemie learning to breathe, a post-operative infant finding their rhythm, or a baby on the edge of extubation.

🧠 The Baby’s Brain Is in Charge

With NAVA, each breath begins not with a sensor in the circuit, but with a spark in the baby’s brain. That electrical signal travels through the phrenic nerves to the diaphragm — and that’s what the NAVA catheter detects.

• The Edi signal shows how much and how often the diaphragm contracts.

• The ventilator converts that signal into assist that’s proportional to the baby’s effort.

• The result is true synchrony — fewer missed triggers, fewer alarms, and often less need for sedation.

💡 Think of NAVA as a conversation: the baby speaks, the ventilator responds.

📈 Reading the Edi: What the Numbers Tell Us

When you stand at the bedside, two numbers on the screen reveal how the baby is managing their work of breathing:

Edi Peak:

• Reflects the baby’s inspiratory effort — the “push” behind each breath.

• Goal: 5–15 µV

• High (>20 µV) → baby is working too hard or undersupported.

• Low (<5 µV) → baby may be oversupported, sedated, or fatigued.

Edi Min:

• Shows the baby’s resting tone between breaths — a marker of functional residual capacity (FRC).

• Goal: <3 µV

• High (>5 µV) → may indicate loss of lung volume; consider a small PEEP increase.

These two numbers are more than data points — they’re real-time feedback on how well our settings match the baby’s physiology.

⚙️ The Settings That Shape Synchrony

Each NAVA parameter connects to a clinical purpose:

• NAVA Level: determines how much work the ventilator shares. Start around 1.0–1.5 cmH₂O/µV and increase until pressures plateau and Edi Peak lands in the 5–15 µV “comfort zone.”

• PEEP: baseline pressure to keep alveoli open (usually 5–6 cmH₂O).

• Edi Trigger: sensitivity of the ventilator to the diaphragm’s signal (typically 0.5 µV).

• Apnea Time: the safety net. A 2–3-second pause triggers backup ventilation if no Edi signal appears.

• Backup Mode: provides breaths at preset pressures and rates when the baby’s drive pauses — not failure, just protection.

Every setting ties directly to what you’ll see on the ventilator screen and hear in the baby’s rhythm.

🔍 What the Screen Shows When It’s All Working

When the catheter is positioned correctly and the baby’s effort is being detected, the ventilator screen tells a clear story:

• The Edi waveform rises smoothly with each spontaneous breath.

• Peaks align perfectly with delivered breaths — synchrony in action.

• The Edi trend line shows stable effort without big swings or missed cycles.

• Backup mode becomes rare; the baby is truly “driving.”

Placement matters. On the catheter positioning screen, you’ll see four ECG-like waveforms:

• Strong P waves on the upper channels that fade on the lower channels confirm correct placement at the diaphragm level.

• Too high? Push in slightly. Too deep? Pull back until the middle leads show the best signal.
  Once the electrodes align, the Edi signal becomes crisp, and suddenly the ventilator feels intuitive — as if it already knows what the baby needs.

🩺 When the Baby Is Ready to Take Over

One of the most exciting uses of NAVA is as a bridge to extubation. For preterm infants, especially those 23–27 weeks, invasive NAVA gives a preview of how the baby will do once they transition to NIV-NAVA (noninvasive).

Clues that a baby is ready to step down include:

• Edi Peak 5–15 µV, Edi Min <3 µV

• Low backup use

• Stable blood gases and FiO₂ ≤0.35

• Minimal C/B/D events on caffeine

Extubating from invasive NAVA to NIV-NAVA allows the baby to keep the same rhythm and signal pathway — just without the tube. It’s one of the smoothest transitions we can offer.

👶 Parent Language: Explaining NAVA Simply

Parents often ask, “How does this ventilator know what my baby needs?”

I like to say:

“This ventilator listens to your baby’s breathing signals. It helps them take a breath when they try — and rests when they rest.”

When families understand that the ventilator is following their baby’s lead, not forcing it, they begin to see progress not as machines working harder, but as their baby growing stronger.

🌈 Final Thoughts

NAVA represents a shift from control to collaboration. It teaches us to look beyond settings and waveforms to see the baby’s own effort — the gentle rise of an Edi peak, the quiet stability of a resting diaphragm.

When we understand what the ventilator is showing us, we’re not just managing a mode — we’re interpreting a dialogue between technology and physiology.

And in the end, that’s what neonatal respiratory care is all about: letting the baby drive, and trusting their signals to guide the way. 💜