Most important to trigger and cycle with patient effort
Just like bagging a spontaneous breathing child, if you aren’t breathing with their inspiratory effort, you are probably just pushing the air into their stomach
Better to choose a lower pressure support that is triggering with their effort over a higher pressure that isn’t
Cycling refers to the pressure being allowed to drop from the pressure support to the peep. If this doesn’t happen when the patient wants, they end up exhaling against a high pressure and again pushing air into their stomach as well as becoming agitated
How to recognize patient is synchronous
The waveform cycles and triggers with noted effort from patient
Why we don’t like adding rates
Set rates have inspiratory times controlled by a time frame and not a flow pattern. Thus, the vent holds the pressure on the patient while the patient attempts to exhale against it pushing air into the stomach and causing agitation
Goes against the patient and ventilator synchrony relationship that we consider the most important aspect when using non-invasive ventilation on the servo
Do not give nebulizers through any mask that covers the eyes (full face /Jason mask)
Mask Fit
Adjusting pressure settings to patient tolerance and mask fit to reduce breakdown
An option is to place a well-fitting, comfortable mask on the patient, where it is not so tight that it will cause breakdown
See what pressure you can effectively trigger and cycle with and the highest pressure support and peep you might deliver (Any higher need would suggest a need to intubate)
Advantages of NIV
Avoid trauma and infection associated with intubation
Intermittent ventilatory assistance
Gradual weaning
Permits normal communication with your patient
Reduction in inspiratory muscle work and avoidance of respiratory muscle fatigue that may lead to acute respiratory failure
Provide ventilatory assistance with greater comfort, convenience and less cost than invasive ventilation
Disadvantages of NIV
Gastric Insufflation
Asynchrony
Inappropriate mask size and fit
Variable leaks
Triggering variables
Patient anxiety
Hemodynamic compromise
Deposition of aerosolized medications in patients’ eyes if given with full face mask
Potential of skin breakdown if mask is to tight or left on for extended periods of time
Modes
Pressure Control Vs.Pressure Support Breaths
A pressure control breath has a set pressure delivered for a set time inspiratory time, while pressure support breaths have a variable I- time
A pressure supported breath will deliver a set pressure until the inspiratory flow decreases to a % of its peak flow (usually 10%), then the breath cycles into exhalation. You can terminate the breath sooner or later by adjusting the % of peak flow (40%-breath will cycle to exhalation sooner, 15%-the breath will cycle to exhalation later)
PS/CPAP
Pressure Support is a patient-initiated breathing mode in which ventilator supports patient effort
Provides a small amount of pressure during inspiration to help patient draw in a spontaneous breath
If PS above PEEP is set to 0, it then becomes CPAP
Reduces work of breathing
NIV NAVA
Estimated pressure delivered = (Edi peak – Edi min) x NAVA level + PEEP + 2 cmH2O
Maximum peak pressure is 32 cmH2O
Leakage Compensation
Adult up to 65 l/min
Infant up to 25 l/min
Disconnect Flow Function
Low flow 7.5 l/min
High flow adult 40 l/min
High flow infant 15 l/min
Enables
Proportional assist in synchrony with the patient’s breathing efforts
Lower assist level
PEEP titration based on Edi Minimum
Objective criteria for intubation decisions
Smooth transition to natural breathing
To manage asynchrony NIV NAVA
Does not rely on a pneumatic signal
Not affected by auto PEEP
Triggering and cycle off independent of leakage
Senses every effort independent of leakage
Patient and ventilator are always in synchrony
Indications for NAVA
Patients at risk for asynchrony with the ventilator
RAM Cannula
Only use NIV NAVA
The patient cannot trigger a breath with flow or pressure triggering through the RAM cannula leading to asynchrony, whereas NIV NAVA triggers by reading the diaphragm
Leaks
During NIV, the ventilator automatically adapts to the variation of leakage in order to maintain the required pressure and PEEP level
Leakage is presented as Leakage fraction % (measurement of how well the mask fits the patient’s face)
Volumes shown in the Measured Value box and volume waveform are compensated for leakage
If leakage is excessive (>65 l/m for adults and > 25 l/m for infants) or during disconnection, the ventilator will pause ventilation and issue a high priority alarm. The ventilation will automatically restart when a breath is detected (i.e. leak is resolved)
To manually restart ventilation, re-adjust interface for better seal or press “Start ventilation”