This document discusses Neurally Adjusted Ventilatory Assist (NAVA), a mode of ventilation that uses diaphragm electrical activity (Edi) to trigger and cycle breaths. It describes the Edi catheter used to measure diaphragm activity, and the procedure for positioning the catheter. Settings for the NAVA mode include the NAVA level, trigger threshold, and cycling-off point. NAVA aims to improve patient-ventilator synchrony compared to other modes and allow proportional support based on patient effort.

1. Neurally Adjusted Ventilatory Assist
NAVA
Θεόδωρος Βασιλακό ουλος
Καθηγητής Πνευ ονολογίας Εντατικής Θερα είας
Εθνικό Κα οδιστριακό Πανε ιστή ιο Αθηνών
Νοσοκο είο ο Ευαγγελισ ός
Γενικός Γρα ατέας
Ελληνικής Πνευ ονολογικής Εταιρείας

2. NAVA

4. Edi
VT
Health Disease
Neuroventilatory coupling

5. NAVA

6. NAVA accessories

7. Edi Catheter

8. Edi Catheters
Inter Electrode Distance (IED)

9. Edi Catheters
Package
▪ Each Edi Catheter is sterile and
packed individually
▪ Package can be used for dipping
the Edi Catheter in water
▪ Instruction for insertion and
positioning of the Edi Catheter
come with the package of each Edi
Catheter
▪ Delivered in boxes of 5

10. Edi Module
– One slot Plug-In module
– Interchangeable
– 50 Hz and 60 Hz
– Filtering to retrieve the Edi and ECG signals
– Processing the Edi signal
– Edi Module cable + Edi Test plug for function check

11. Function test

12. Edi Catheter positioning procedure
The NEX-measure

13. Insertion distance Y for nasal insertion
NEX cm x 0.9 + 2.5 = Y cm
6 Fr 49 cm
NEX cm x 0.9 + 3.5 = Y cm
6 Fr 50 cm
NEX cm x 0.9 + 8 = Y cm
8 Fr 100 cm
NEX cm x 0.9 + 18 = Y cm
8 Fr 125 cm
NEX cm x 0.9 + 15 = Y cm
12 Fr
NEX cm x 0.9 + 18 = Y cm
16 Fr
Calculation of Y
Fr/cm
Insertion distance Y for nasal insertion
NEX cm x 0.9 + 2.5 = Y cm
6 Fr 49 cm
NEX cm x 0.9 + 3.5 = Y cm
6 Fr 50 cm
NEX cm x 0.9 + 8 = Y cm
8 Fr 100 cm
NEX cm x 0.9 + 18 = Y cm
8 Fr 125 cm
NEX cm x 0.9 + 15 = Y cm
12 Fr
NEX cm x 0.9 + 18 = Y cm
16 Fr
Calculation of Y
Fr/cm
Edi Catheter positioning procedure
Nasal insertion

14. Insertion distance Y for oral insertion
NEX cm x 0.8 + 2.5 = Y cm
6 Fr 49 cm
NEX cm x 0.8 + 3.5 = Y cm
6 Fr 50 cm
NEX cm x 0.8 + 8 = Y cm
8 Fr 100 cm
NEX cm x 0.8 + 18 = Y cm
8 Fr 125 cm
NEX cm x 0.8 + 15 = Y cm
12 Fr
NEX cm x 0.8 + 18 = Y cm
16 Fr
Calculation of Y
Fr/cm
Insertion distance Y for oral insertion
NEX cm x 0.8 + 2.5 = Y cm
6 Fr 49 cm
NEX cm x 0.8 + 3.5 = Y cm
6 Fr 50 cm
NEX cm x 0.8 + 8 = Y cm
8 Fr 100 cm
NEX cm x 0.8 + 18 = Y cm
8 Fr 125 cm
NEX cm x 0.8 + 15 = Y cm
12 Fr
NEX cm x 0.8 + 18 = Y cm
16 Fr
Calculation of Y
Fr/cm
Edi Catheter positioning procedure
Oral insertion

15. Edi Catheter positioning procedure
Insert the Edi Catheter

16. Edi Catheter positioning procedure
Connect the cable

17. Edi Catheter positioning procedure
Neural access

18. Edi Catheter positioning procedure
Edi Catheter positioning window
▪ Four ECG waveforms for
Edi catheter position
▪ Edi waveform
▪ Scale and sweep speed
settings
▪ Freeze function
▪ Numerical values of Edi
peak and Edi min

19. Edi Catheter positioning procedure
Position and Edi signal

20. Edi Catheter positioning procedure
Position and Edi signal

21. Edi Catheter positioning procedure
Position and Edi signal

22. Select ventilation mode

23. Set NAVA ventilation mode

24. P (cm H2O)
Edi (μV)
20
10
10
20
1
0.5
2
4
NAVA level

25. Edi trigger level

26. Edi cycling off

27. NAVA preview
▪ Estimated Ppeak (Pest) in NAVA =
= NAVA Level x (Edi peak – Edi min) + PEEP

28. Additional settings
NAVA
NAVA (PS)
Backup NAVA (PC)

29. Running in NAVA mode

30. NAVA Backup function
NAVA Backup NAVA (PC)

31. Low Edi signal
▪ Hyperventilation
▪ Sedation
▪ Neural disorder
▪ Muscle relaxants

32. Brander L et al. Chest 2009;135:695-703

33. ▪ NAVA level titration
▪ Start at 0.5 NAVA level (gain) and increase in steps of 0.5
▪ Increasing NAVA level :
– Initial pressure (Ppeak) increases until plateau
– Edi softly decreasing
– Tidal Volume increases until plateau
Continue with NAVA level 2
where Tidal Volume plateau starts

34. Colombo D.et al.; Physiologic response to varying levels of Pressure Support and Neurally Adjus-
ted Ventilatory Assist in patients with acute respiratory failure; Intensive Care Med 2008;34:2010-8
- PS had an Asynchrony Index > 10% in 36% of patients
with NAVA 0%
- NAVA limited the risk for over-assist compared to PS
- NAVA clearly improved patient-ventilator interaction
Pressure Support compared to NAVA

35. Edi Monitoring

36. NAVA :
- Better synchrony compared to controlled and assist ventilation modes
- Proportionality to patients demands
- Unloading the diaphragm
by increasing the NAVA level
-