1. Adjusting comfort settings on Newport HT70 Series Ventilators
Narrated by Cyndy Miller, RRT

2. Comfort and Synchrony
HT70 “Comfort” settings impact patient-ventilator synchrony.
Synchrony impacts time to liberation for those patients who are weaning from the ventilator.
Comfort impacts well being for those who are ventilator dependent.
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3. Dys-synchrony-Discomfort
Patient looks uncomfortable or tells you they are uncomfortable.
Patient doesn’t reliably trigger the ventilator when Trigger is set at a normal trigger setting.
Unusually high or low respiratory rate.
Double triggering.
Tidal volume fluctuates a lot from breath to breath.
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4. Comfort Settings Condition Adjustment Volume Control breaths
Flow & Flow Waveform
Pressure Control breaths
Slope Rise
Pressure Support breaths
Slope Rise, Expiratory Threshold, PS Max i Time
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5. Comfort Settings: Volume Control Flow and Flow Waveform
Higher Flow
Flow to Patient
Lower Flow
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6. Volume Control Breaths Delivery
End
How does Volume Control work?
Flow delivery is determined by user settings
Flow
Airway Pressure
Pressure is generated by the ventilator to push the set Tidal Volume into the patient
PEEP
Breath ends when the Inspiratory Time elapses/Tidal Volume has been delivered.
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7. Volume Control Breaths – Comfort Settings
You select the Peak Flow.
You select the Flow Pattern.
The Peak Flow and Flow Pattern don’t change even if the patient inhales at a higher or lower flow.
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8. Volume Control Breaths – (Peak) Flow
(Peak) Flow is set on the Main Screen
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9. Volume Control Breaths – (Peak) Flow
Patients who are spontaneously breathing will already be inhaling at a particular flowrate.
If ventilator Flow is set too low, the patient will work harder to breathe.
The (Peak) Flow you set must be at or above the patient’s spontaneous flowrate in order for the ventilator to take the workload away from the patient.
Increase the (Peak) Flow setting until you see pressure rise smoothly when the patient inhales and you see the breath end in time to allow full exhalation (avoid auto-PEEP).
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10. Volume Control Breaths – (Peak) Flow
Typical flowrates in Volume Control:
Adults L/min
Pediatrics: L/min
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11. Volume Control Breaths – (Peak) Flow
Setting (Peak) Flow for patients who are not spontaneously breathing should be focused on achieving appropriate breath timing.
Set Flow so that the patient has plenty of time to exhale in order to avoid auto-PEEP.
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12. Volume Control Breaths – (Peak) Flow
Flow and Inspiratory Time are mathematically linked.
Setting the Flow at a higher flowrate means making the breath shorter. And vise verse.
If you increase the Flow to meet patient’s needs, it could make the Inspiratory Time too short.
Flow
Time
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13. Volume Control Breaths – (Peak) Flow
Increasing the Flow setting (decreasing Inspiratory Time) to meet the flow demands of an actively breathing patient can cause double triggering and dys-synchrony if patient effort continues past when the breath ends. . V S
L/min 1 2 3 4 5 6
The need for higher flow may be remedied by changing from a Square to Descending Ramp Flow Waveform first, then adjusting Flow.
When you change to a Descending Ramp, the flowrate is automatically increased without shortening inspiratory time.
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14. Volume Control Breaths - Flow Waveform
Flow Waveform is set on the More Screen
(along with other “comfort settings”)
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15. Volume Control Breaths - Flow Waveform
There are two selections:
Square
Descending Ramp
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16. Volume Control Breaths - Flow Waveform
Challenge
Situation: VT 350 mL
Square Wave - Flow 30 L/min.
Insp Time 0.7 s
Patient is stressed and needs more flow.
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17. Volume Control Breaths - Flow Waveform
Challenge
Situation: VT 350 mL
Square Wave - Flow increased to 50 L/min.
Caused Insp Time to decrease to 0.4 s
Inspiratory Time too short, double triggering occurs. Pt-ventilator dys-synchrony and fatigue follow.
This did not solve the problem.
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18. Volume Control Breaths - Flow Waveform
Challenge
Situation: VT 350 mL
Change to Descending Ramp Flow Wave –
Set Flow to 50 L/min.
Insp Time is now 0.6 s! Adequate for the patient.
Patient is now comfortable.
Flow needs are met without the breath being too short!
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19. Comfort Settings: Pressure Control Slope/Rise
Faster (set closer to 1) Slope Rise
Slower (set closer to 10) Slope Rise
Target Pressure
PEEP
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20. Pressure Control Breaths Delivery
How does Pressure Control work?
Flow delivery is a result of:
Pressure change needed,
Slope Rise setting,
patient effort
and patient pulmonary mechanics.
Flow
Airway Pressure
Pressure delivery is determined by pressure change needed (difference between PC setting and PEEP).
PEEP
The actual target pressure is the PC setting above room pressure, (not above PEEP)
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21. Pressure Control Breaths End
How does a Pressure Control breath end?
Flow
Breath ends when the Inspiratory Time elapses.
Airway Pressure
PEEP
The user set Inspiratory Time determines the duration of the breath
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22. Pressure Control Breaths – Slope Rise
The Slope Rise setting determines the rate of pressure rise to the Pressure Control level.
Airway
Pressure
PC setting
PEEP
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23. Pressure Control Breaths – Slope Rise
Slope Rise is set on the More Screen
(along with other “comfort settings”)
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24. Pressure Control Breaths – Slope Rise
Range= 1-10
HT70 Plus = 1 fastest
HT70 = 10 fastest
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25. Pressure Control Breaths – Slope Rise Work of Breathing
A faster Slope-Rise with a squared pressure waveform delivers a higher peak-flow and higher machine assistance for the patient at the onset of the breath.
A slower Slope-Rise with a slanted pressure waveform delivers a lower peak-flow and less machine assistance for the patient at the onset of the breath.
Target Pressure
Airway
Pressure
PEEP
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26. Pressure Control Breaths – Slope Rise Volume Delivery
A faster Slope Rise can provide the opportunity for earlier volume delivery into the alveoli.
Remember that alveolar pressure always lags behind airway pressure.
When airway pressure rises slowly, alveolar pressure rises even more slowly.
If it rises too slowly, alveolar pressure may not even reach the target peak pressure before the breath ends.
Target Pressure
PEEP
If the user does not change Inspiratory Time, a faster Slope Rise setting may deliver a higher tidal volume.
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27. Pressure Control Breaths – Slope Rise
How can you tell if Slope Rise is set too fast?
“Ringing” in the flow waveform
Sounds like “ch ch ch ch ch”
Flow
Slow it down a little
HT70 = Set it at lower number
HT70 Plus = Set it at higher number
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28. Comfort Settings: Pressure Support
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29. Pressure Support Breaths Delivery
How does Pressure Support work?
Flow delivery is a result of the pressure change that must happen, the Slope Rise setting, the Expiratory Threshold setting, the PS Max i Time setting, patient effort and patient pulmonary mechanics.
Flow
Airway Pressure
Pressure delivery is determined by pressure change needed (the actual PS setting).
PEEP
The Pressure Support setting IS the pressure change (above PEEP).
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30. Pressure Support Breaths End
How does a Pressure Support breath end?
It ends by one of three mechanisms:
Flow delivery drops to a user-set percent of the peak flow.
Pressure rises 3 cmH2O/mbar above the target pressure.
The breath duration reaches the user-set PS Max i Time setting.
100% of Peak Flow
Flow
Set from 5-85% of Peak Flow
Target Pressure + 3 cmH2O
Target Pressure
PS setting + PEEP
PAW
PEEP
PS Max i time = Maximum inspiratory time for pressure support breaths set from 0.1 to 3 seconds.
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31. Comfort Settings: Pressure Support Slope/Rise
Faster (set closer to 1) Slope Rise
Slower (set closer to 10) Slope Rise
Target Pressure
PEEP
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32. Pressure Support Breaths – Slope Rise
Pressure Support breaths and Pressure Control breaths use the same Slope Rise setting and it works the same for both breath types.
Airway
Pressure
Target Pressure
PEEP
HT70 = 10 fastest
HT70 Plus = 1 fastest
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33. Pressure Support Breaths – Slope Rise
So we don’t need to cover it again, right?
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34. Comfort Settings: Pressure Support Expiratory Threshold & PS Max i Time
5% = longest setting,
85% = shortest setting
Flow
Expiratory Threshold
Set from 5-85% of Peak Flow
PS Max I Time Set from seconds
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35. Pressure Support Breaths End
User sets Expiratory Threshold and PS Max i Time
100% of Peak Flow
Flow
User does not set the pressure cycling off value.
It is preset and not user adjustable.
The pressure cycling off mechanism is intended to end the breath automatically if the patient exhales and pressure rises.
Expiratory Threshold
Set from 5-85% of Peak Flow
Pressure rises 3 cmH2O above target pressure (not adjustable)
PAW
Target Pressure
PEEP
PS Max i time Set from 0.1 to 3 seconds.
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36. Pressure Support Breaths – Expiratory Threshold
Expiratory Threshold is set on the More Screen
(along with other “comfort settings”)
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37. Pressure Support Breaths – Expiratory Threshold
During a pressure support breath, flow starts out at a higher level and decelerates (declines) to a lower level.
How many of you know why the flow rate decelerates?
Flow
Time
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38. Pressure Support Breaths – Expiratory Threshold
If flow keeps going at a preset rate, pressure keeps climbing. . V
Paw
cmH2O/
mbar
In order to keep pressure at the airway from rising above the target pressure, flow delivery from the ventilator must decline in direct proportion to the rate that the lungs fill.
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39. Pressure Support Breaths – Expiratory Threshold
The maximum flow delivered during the breath is called the “Peak Flow”
Peak Flow
Expiratory Threshold = a % of Peak Flow
Inspiration
Exhalation
Flow
When flow drops from the peak flow to the % of peak flow set as the Expiratory Threshold, the breath cycles from inspiration to exhalation
Time
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40. Pressure Support Breaths – Expiratory Threshold
Example
If the Peak Flow is 100 L/min
Peak Flow = 100 L/min
Expiratory Threshold = 33%
Flow = 33 L/min
And Expiratory Threshold is set at 33%
Inspiration
Exhalation
Flow
The breath will change from the inspiratory phase to the expiratory phase when flow delivery to the patient drops from 100 L/min down to 33 L/min
Time
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41. Pressure Support Breaths – Expiratory Threshold
Causes Pressure Support to cycle to exhalation when the patient stops inhaling
Expiratory Threshold is an indirect setting for inspiratory time.
The relationship between Expiratory Threshold and inspiratory time is a bit complex……………..
An ideal expiratory threshold setting =
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42. Pressure Support Breaths – Expiratory Threshold
Some people’s lungs fill/empty slowly
Some people’s lungs fill/empty quickly
Flow
This is called a long time constant.
This is called a short time constant
Time
Time Constant is the product of compliance and resistance.
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43. Pressure Support Breaths – Expiratory Threshold
To end up with a normal inspiratory time, the patient on the left (long time constant) needs a much higher Exp Threshold (% of peak flow) setting than the patient on the right (short time constant).
Flow
Insp Time = ~1 sec
Time
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44. Pressure Support Breaths – Expiratory Threshold
If Expiratory Threshold Too Low
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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45. Pressure Support Breaths – Expiratory Threshold
The breath may cycle-off too late
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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46. Pressure Support Breaths – Expiratory Threshold
This can cause the patient to exhale against continuing support
Flow
Target Pressure
Airway
Pressure
PEEP
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47. Late cycling off can cause an increase in work, fatigue and delayed liberation (delayed weaning) from mechanical ventilatory support.
And also cause the ventilator to miss triggering a breath in response to the patient’s next breathing effort
Flow
Missed Triggers are one of the most common causes of weaning delay
Target Pressure
Airway
Pressure
PEEP
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48. Pressure Support Breaths – Expiratory Threshold
If Expiratory Threshold Too High
Flow
Early cycling off may occur and this commonly causes double triggering, followed by a “missed trigger”.
Target Pressure
Airway
Pressure
PEEP
Time (s)
Both early and late cycling off can cause missed triggers and discomfort/delayed liberation from mechanical ventilation.
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49. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Setting for Slope Rise and setting for Expiratory Threshold are interrelated
Flow
Time
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50. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
If you have a patient who can benefit from extra assistance at the beginning of the breath, you need make the Slope Rise faster, right?
Flow
Time
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51. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Be careful.
Making the Slope Rise faster will cause the Expiratory Threshold setting to be reached sooner, so the breath will get shorter if you don’t lower the Expiratory Threshold setting at the same time.
Flow
Time
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52. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Watch this example!
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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53. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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54. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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55. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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56. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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57. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
Target Pressure
Airway
Pressure
PEEP
Time (s)
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58. Pressure Support Breaths – Slope Rise & Expiratory Threshold Interactivity
Flow
If you make Slope Rise faster and that change results in double triggering, it means that you need to lower the Expiratory Threshold setting.
Target Pressure
Airway
Pressure
PEEP
Time (s)
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59. Early cycling off Late cycling off Ch ch ch ch ch ch
That’s the sound of double triggering!!
Early cycling off
Ch ch ch ch ch ch
Late cycling off
Tidal volume fluctuate a lot.
Rate is lower.
That’s missed triggering and auto-PEEP!
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60. Pressure Support Breaths – PS Max i Time
What happens if there is a leak in the system?
Flow may not decline during Pressure Support because the ventilator is trying to keep pressure in the “Big Lung” at the target pressure.
PS Max i Time to the rescue!
PS Max i Time set at 1.2 seconds
Flow
Target Pressure
PAW
PEEP
Hint: Big Lung is the room!
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61. Pressure Support Breaths – PS Max i Time
PS Max i Time is set on the More Screen
(along with other “comfort settings”)
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62. Pressure Support Breaths – PS Max i Time
This setting determines the maximum time allowable for a Pressure Support Breath.
Even if flow never declines and the Expiratory Threshold is never met, the breath will stop when this time setting elapses.
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63. Pressure Support Breaths – PS Max i Time versus Expiratory Threshold
So which has the ultimate control?
PS Max i Time or PS Expiratory Threshold?
PS Max I Time
Expiratory Threshold
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64. Pressure Support Breaths – PS Max i Time versus Expiratory Threshold
Whichever is achieved first!
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65. How to fix early cycling off
Review
Decrease the Expiratory Threshold Setting to lengthen the breath
Lengthen the PS Max i Time Setting to stop from cutting the breath short
For mandatory breaths, lengthen the inspiratory time
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66. How to fix late cycling off
Review
Increase the Expiratory Threshold Setting to shorten the breath
Shorten the PS Max i Time Setting to cut the breath off in case of a leak
For mandatory breaths, shorten the inspiratory time
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67. Quick Comfort Summary
Adjust Flow and Flow Waveform to ensure optimal flow support (ventilator does the work) and the most compatible inspiratory time during Volume Control breaths.
Adjust Slope Rise to ensure optimal flow support (ventilator does the work) at the onset of every Pressure Support and Pressure Control breath.
Adjust Expiratory Threshold to create a compatible inspiratory time for all Pressure Support breaths.
Adjust PS Max i Time to create a failsafe back up cycling off mechanism in case a leak in the circuit or around the patient’s mask or artificial airway causes flow to remain high during Pressure Support breaths.
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68. Getting Help is Easy Urgent! NON-Urgent
Clinical questions -
Technical questions -
Call Cyndy Miller ext. 218
NON-Urgent
Call
Clinical Assistance 24/7 Hotline: Ext. 123
Technical Service 24/7 Hotline: Ext. 500
Urgent!
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69.
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70. End of the Presentation
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