Less than 15 kg = infant circuit (Bias flow- 0.5 Lpm) =infant circuit
Greater than 15 kg = pedi / adult circuit (Bias flow-2 Lpm) = adult circuit
Circuit compliance should remain on at all times
If turned off, physician should be notified and vent order modified in comments
If turned off in NICU physician should be notified and circuit compliance card should be placed on the ventilator
Examples of compliance being turned off:
Large unresolvable leak with uncuffed tube
Very low return volumes to vent due to ECMO rest settings
Small volumes of infants on INO
How to Ventilate
Manipulate minute volume by adjusting:
Rate
Volume/Pressure
How to Oxygenate
Adjust FiO2
Manipulate MAP by adjusting:
PEEP
PIP
I-time
Alarms
High Airway Pressure Alarm
Should be set at 5 cmH2O above the peak airway pressure
PEEP Alarm
No more than 3 cmH2O above or below set PEEP
Minute Volume Alarms
High and low minute volume alarms should not exceed more than 25% of the exhaled minute volume
If patient condition, such as a known airway leak is creating a constant alarm, the physician must be contacted and new parameters should be ordered
High Respiratory Rate
Should be set no more than 15 BPM above the current respiratory rate
Apnea
Apnea time of 20 seconds or less
All other apnea parameters will be set as ordered
Pressure Ventilation
Ventilator maintains a set airway pressure for a given inspiratory time. Pressure is constant while the tidal volume can be variable depending on patient characteristics (compliance, airway/tubing resistance) and driving pressures
Each breath is either an assist or control breath
Advantages:
Less risk of barotrauma
The inspiratory flow pattern adjusts to patients airway resistance and thus only uses as fast of a flow as required to hold the target pressure
Guarantees a given pressure with every breath and thus is great with patient airway leaks
Disadvantages:
Tidal Volumes are dependent on respiratory compliance and resistance
Uncontrolled volumes can lead to volutrauma
Therapy can greatly change pre and post volumes and thus require PIP changes
Pressure Control SIMV with Pressure Support
Mandatory breaths are pressure control breaths (controlled) and time-cycled
Spontaneous breaths are pressure support (supported) and flow-cycled
Ventilator provides mandatory breaths which are synchronized with patients spontaneous efforts at a preset rate over a minute
Decelerating waveform is targeted with your rise function
Benefits
Lung protection from high pressures
Guarantees a delivered pressure with every breath
More waveform information referrring to fill times and varying airway resistances
Disadvantages
Volumes delivered are not constant and are affected by changes in the lungs, airway, etc.
May need frequent Pip changes
Volume Control
Ventilator maintains a set volume for a given inspiratory time. Volume is constant while the airway pressures (peak, plateau, and mean) depend on both the ventilator settings and patient-related variables (eg, compliance, airway resistance). High airway pressures may be a consequence of large tidal volumes, a high peak flow, poor compliance (eg, acute respiratory distress syndrome, minimal sedation), or increased airway resistance
Advantages
Guaranteed Tidal Volumes produce more stable minute volume
Minute volume remains stable over a range of changing pulmonary characteristics
Disadvantages
MAP is lower
Recruitment may be poorer in lungs with low compliance
Very structured flow delivery with each breath that may not match the airway need
In general, the Pip will be higher than what is needed in pressure control to obtain the same volume
Availability for abrupt pressure spikes from breath to breath, especially with under sedated patients
Volume Control SIMV with Pressure Support
Mandatory breaths are Volume Control breaths (controlled)
Spontaneous breaths are pressure support (supported)
Ventilator provides mandatory breaths which are synchronized with patient’s spontaneous efforts at a preset rate
Square waveform
Benefits
Volumes delivered are constant despite lung, airway condition
Disadvantages
High pressures needed to deliver preset volumes may lead to barotrauma
Square waveform
PRVC
Considered a pressure mode as the breaths given are pressure breaths with a decelerating inspiratory flow (more physiologic & comfortable), but targets a set tidal volume so that you can ensure adequate tidal volumes as lung compliance changes. If compliance decreases, then more pressure is needed to achieve the set tidal volume
The servo is using inspiratory tidal volume to measure the target volume, while the Draeger uses expiratory tidal volume
The Servo breath limits and alarms when pressure needed reaches 5cmH20 below the preset pressure limit and dumps if high pressure alarm is reached
Benefits
Has a decelerating waveform which is more natural to the patient and leads to better gas distribution
Controlled in part by the rise time function
Pressure automatically adjusted for changes in compliance and resistance within a set range to maintain lowest pressure
Tidal volume “guaranteed"
Limits volutrauma/barotrauma
Prevents hypoventilation
Disadvantages
Pressure delivered is dependent on tidal volume achieved on last breath
Varying mean airway pressure
May cause or worsen auto-PEEP
Use with caution in patients with noted airway leaks, as they will affect actual volume delivered
May be tolerated poorly in awake non-sedated patients
When patient inspiratory demand is elevated, pressure level may decrease leading to less support
Coughing, suctioning, patient desynchrony can affect the following breaths and give either larger or smaller volumes than intended
PRVC SIMV with Pressure Support
PRVC with the ability to have spontaneous breathing
Mandatory breaths are PRVC breaths (controlled) and time-cycled
Spontaneous breaths are pressure support (supported) and flow-cycled
Ventilator provides mandatory breaths which are synchronized with patients spontaneous efforts at a preset rate
Pressure Support/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 just CPAP
Reduces work of breathing
Volume Support
Similar to pressure support but the tidal volume is monitored and the Pressure Support level is adjusted each breath to attempt to reach the target volume
The patient initiates the breath and the ventilator delivers support in proportion to the inspiratory effort and target volume
The set volume is delivered to the patient with variable support and targeted on either expiratory or inspiratory tidal volume depending on which vent is being used
Automode
Allowed to use with: Pressure Control, Volume Control and PRVC modes
Allows for a target PIP/volume depending on underlying mode
Set a trigger timeout time. When pt fails to trigger the vent within the allotted time, vent will cycle out of Automode into assist control mode
Automatically controls the transition between controlled (ventilator triggered) and support (patient triggered) mode in accordance with the patient’s breathing effort
Allows patient to go into support mode automatically if they trigger the vent:
Pressure control into Pressure Support
Volume control into Volume Support
PRVC into Volume Support
Disadvantages
Pt will receive set Vt/PIP with every breath. Potential to over-ventilate
Possibility of asynchrony with effort
Benefits
Allows pt to work respiratory muscles without the RT having to switch modes frequently
Good mode for weaning. No need for PS/CPAP trials as patient is already determining amount of support needed
Allows to better determine when a patient is nearing readiness to extubate