10 - NAVA & ECMO

neurally adjusted ventilatory support (NAVA)

ventilation that uses diaphragm electrical activity (E_di) to control breath timing and support level

goal of NAVA

improve patient-ventilator synchrony

E_di catheter

NG tube with electrodes that detect electrical signals

neural triggering

ventilator uses brain-to-diaphragm signal to start inspiration

proportional support

strong neural drive → more ventilatory assist

key NAVA parameters

• NAVA level

pressure assist per diaphragm signal strength

• usually 0.5-3 cmH₂O/µV

key NAVA parameters

• E_di peak

inspiratory effort 

• usually 5-15 µV

key NAVA parameters

• E_di minimum

baseline tone

• should not be 0

key NAVA parameters

• backup mode

ventilator switches to conventional control if E_di is lost

advantages of NAVA

• perfect synchrony

• prevents over-assistance

• improves comfort

• supports weaning

• great for neonates

limits of NAVA

• must confirm E_di catheter placement

• not always available

• contraindicated in phrenic nerve injury or paralysis

• needs training to interpret signals

diseases and conditions using NAVA

• RDS

detects weak signals, avoids barotrauma

diseases and conditions using NAVA

• BPD

adapts to changing C_L

diseases and conditions using NAVA

• apnea of prematurity

detects early diaphragm activity

diseases and conditions using NAVA

• post-extubation support

prevents re-intubation

diseases and conditions using NAVA

• bronchiolitis/RSV

improves comfort

maintenance issues with ECMO

• venous side

• clots

• decreased volume (tube “chattering”)

• malposition of cannula

• kink in tube

maintenance issues with ECMO

• arterial side

• clots

• malposition of cannula

• kink in tube

emergencies for ECMO

• decannulation

• machine failure

• cardiac event (VA)

• air bubble