Trigger All breaths on a ventilator need to be triggered
Slide 3
Trigger All breaths on a ventilator need to be triggered They
can be Time triggered
Slide 4
Trigger All breaths on a ventilator need to be triggered They
can be Time triggered Patient triggered
Slide 5
Trigger All breaths on a ventilator need to be triggered They
can be Time triggered Patient triggered Flow triggered
Slide 6
Trigger All breaths on a ventilator need to be triggered They
can be Time triggered Patient triggered Flow triggered Pressure
triggered
Slide 7
Time triggering Time triggering means the ventilator starts the
breath
Slide 8
Time triggering Time triggering means the ventilator starts the
breath This will happen when there is no patient effort
Slide 9
Time triggering Time triggering means the ventilator starts the
breath This will happen when there is no patient effort This is
based on the set respiratory rate
Slide 10
Patient Triggering A breath can be triggered by the
patient
Slide 11
Patient Triggering A breath can be triggered by the patient
Flow triggering is the most common
Slide 12
Patient Triggering A breath can be triggered by the patient
Flow triggering is the most common Pressure triggering is another
option
Slide 13
Flow Triggering Flow triggering starts with a base flow This
flow is continuously flowing through the circuit
Slide 14
Flow Triggering Flow triggering starts with a base flow This
flow is continuously flowing through the circuit The ventilator
knows how much flow is going through the circuit The liter flow
leaving the ventilator should be the same as the liter flow coming
back
Slide 15
Flow Triggering As the patient inhales some of the flow goes
into the patient lungs This means less flow is returning to the
ventilator The ventilator senses that as a patient effort and
starts a breath
Slide 16
Flow Triggering The difference in the flow coming out of the
ventilator and coming back to the ventilator is how sensitivity is
determined The less flow needed to be deflected by the patient the
more sensitive it is The more flow needed to be deflected by the
patient the more difficult it is to trigger, i.e. less
sensitive
Slide 17
Flow Triggering 10 lpm is leaving the ventilator 10 lpm is
returning to the ventilator As a patient inhales and takes in 2 lpm
8 lpm is returning to the ventilator This reduction in returned
flow tells the ventilator to start a breath
Slide 18
Flow Triggering If you increase the amount of flow needed to be
inhaled by the patient the less sensitive the machine is 10 lpm is
leaving the ventilator 10 lpm is returning to the ventilator As a
patient inhales and takes in 4 lpm 6 lpm is returning to the
ventilator
Slide 19
Pressure Triggering Negative pressure is generated when a
patient inhales
Slide 20
Pressure Triggering Negative pressure is generated when a
patient inhales This negative pressure is in both the patients
lungs and the ventilator circuit
Slide 21
Pressure Triggering Negative pressure is generated when a
patient inhales This negative pressure is in both the patients
lungs and the ventilator circuit The ventilator senses the negative
pressure as a patient effort and starts a breath
Slide 22
Pressure Triggering So the patient needs to generate -2cmH2O to
start a breath If you increase the amount of negative pressure
needed the more difficult it is for the patient to trigger, i.e.
less sensitive
Slide 23
Limiting Limiting is what contols are in effect during the
inspiratory phase
Slide 24
Limiting Limiting is what contols are in effect during the
inspiratory phase After a breath is initiated certain limits will
be in effect depending on which type of breath is being
delivered
Slide 25
Limiting Limiting is what contols are in effect during the
inspiratory phase After a breath is initiated certain limits will
be in effect depending on which type of breath is being delivered
Limiting factors are what define a type of breath
Slide 26
Limiting Limiting is what contols are in effect during the
inspiratory phase After a breath is initiated certain limits will
be in effect depending on which type of breath is being delivered
Limiting factors are what define a type of breath The two most
common limits are
Slide 27
Limiting Limiting is what contols are in effect during the
inspiratory phase After a breath is initiated certain limits will
be in effect depending on which type of breath is being delivered
Limiting factors are what define a type of breath The two most
common limits are Pressure
Slide 28
Limiting Limiting is what contols are in effect during the
inspiratory phase After a breath is initiated certain limits will
be in effect depending on which type of breath is being delivered
Limiting factors are what define a type of breath The two most
common limits are Pressure Flow
Slide 29
Pressure Limited Pressure limited breaths have a set peak
airway pressure
Slide 30
Pressure Limited Pressure limited breaths have a set peak
airway pressure The pressure in the patients lungs will not go over
the set pressure
Slide 31
Pressure Limited Pressure limited breaths have a set peak
airway pressure The pressure in the patients lungs will not go over
the set pressure The following breaths are pressure limited
Slide 32
Pressure Limited Pressure limited breaths have a set peak
airway pressure The pressure in the patients lungs will not go over
the set pressure The following breaths are pressure limited PCV PSV
PRVC
Slide 33
Pressure Limited Pressure Control Ventilation (PCV) Pressure is
set with the intention of reaching the peak pressure and holding
the pressure for part of the inspiratory time
Slide 34
Pressure Limited Pressure Control Ventilation (PCV) Pressure is
set with the intention of reaching the peak pressure and holding
the pressure for part of the inspiratory time Pressure Support
Ventilation (PSV) Pressure is set to augment a patients own tidal
volume
Slide 35
Pressure Limited Pressure Control Ventilation (PCV) Pressure is
set with the intention of reaching the peak pressure and holding
the pressure for part of the inspiratory time Pressure Support
Ventilation (PSV) Pressure is set to augment a patients own tidal
volume Pressure Regulated Volume Control (PRVC) Pressure changes
with each breath with the intention of reaching a specific
volume
Slide 36
Flow Limited Flow limiting is used when a specific volume needs
to be delivered
Slide 37
Flow Limited Flow limiting is used when a specific volume needs
to be delivered Each breath has a rigid flow rate and pattern that
will deliver the specific volume
Slide 38
Flow Limited Flow limiting is used when a specific volume needs
to be delivered Each breath has a rigid flow rate and pattern that
will deliver the specific volume Therefore the breath is limited to
a predetermined flow Volume Control is a type of flow limited
breath
Slide 39
Pressure vs. Flow Limiting Pressure limited breaths have a
variable flow which allows better gas distribution
Slide 40
Pressure vs. Flow Limiting Pressure limited breaths have a
variable flow which allows better gas distribution The pressure is
limited therefore if lung conditions change the volume will
change
Slide 41
Pressure vs. Flow Limiting Pressure limited breaths have a
variable flow which allows better gas distribution The pressure is
limited therefore if lung conditions change the volume will change
If lungs become stiffer the volume will go down as the pressure
remains the same
Slide 42
Pressure vs. Flow Limiting Flow limiting will deliver a volume
no matter what the lung conditions
Slide 43
Pressure vs. Flow Limiting Flow limiting will deliver a volume
no matter what the lung conditions Volume will be consistent but
pressures will change
Slide 44
Pressure vs. Flow Limiting Flow limiting will deliver a volume
no matter what the lung conditions Volume will be consistent but
pressures will change If the lungs become stiffer the pressures
will go up
Slide 45
Pressure vs. Flow Limiting PRVC uses pressure limiting but will
automatically adjust the pressure to deliver a volume
Slide 46
Pressure vs. Flow Limiting PRVC uses pressure limiting but will
automatically adjust the pressure to deliver a volume So the
pressure is not set, the volume is set
Slide 47
Pressure vs. Flow Limiting PRVC uses pressure limiting but will
automatically adjust the pressure to deliver a volume So the
pressure is not set, the volume is set The ventilator will adjust
the pressure to achieve the volume
Slide 48
Pressure vs. Flow Limiting PRVC uses pressure limiting but will
automatically adjust the pressure to deliver a volume So the
pressure is not set, the volume is set The ventilator will adjust
the pressure to achieve the volume This allows for the variable
flow which is better for gas distribution
Slide 49
Pressure vs. Flow Limiting PRVC uses pressure limiting but will
automatically adjust the pressure to deliver a volume So the
pressure is not set, the volume is set The ventilator will adjust
the pressure to achieve the volume This allows for the variable
flow which is better for gas distribution If the lungs become
stiffer the pressures will go up
Slide 50
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale
Slide 51
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale Most breaths are time cycled
Slide 52
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale Most breaths are time cycled Any breath
type that requires a set Ti is time cycled These include the
following breath types
Slide 53
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale Most breaths are time cycled Any breath
type that requires a set Ti is time cycled These include the
following breath types PRVC
Slide 54
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale Most breaths are time cycled Any breath
type that requires a set Ti is time cycled These include the
following breath types PRVC PCV
Slide 55
Cycling Cycling is what determines how the breath will stop and
allow the patient to exhale Most breaths are time cycled Any breath
type that requires a set Ti is time cycled These include the
following breath types PRVC PCV Volume Control
Slide 56
Cycling Flow is also used to cycle a breath off
Slide 57
Cycling Flow is also used to cycle a breath off Pressure
Support Ventilation (PSV) is flow cycled
Slide 58
Cycling Flow is also used to cycle a breath off Pressure
Support Ventilation (PSV) is flow cycled As the inspiratory flow
starts to slow down the ventilator will sense that the lungs are
getting full and cycle off allowing the patient to exhale
Slide 59
Cycling Flow is also used to cycle a breath off Pressure
Support Ventilation (PSV) is flow cycled As the inspiratory flow
starts to slow down the ventilator will sense that the lungs are
getting full and cycle off allowing the patient to exhale During
that same breath it is being pressure limited
Slide 60
Cycling Flow is also used to cycle a breath off Pressure
Support Ventilation (PSV) is flow cycled As the inspiratory flow
starts to slow down the ventilator will sense that the lungs are
getting full and cycle off allowing the patient to exhale During
that same breath it is being pressure limited So pressure is being
held in the lungs until the flow slows down at which time the
ventilator will release the pressure and the patient exhales
Slide 61
Baseline Baseline is what limits are in effect during
exhalation Exhalation is passive The only limit will be added
pressure, i.e. PEEP The baseline should be assessed via total PEEP
to accurately measure the baseline
Slide 62
Rise Time or Slope Rise time is part of the inspiration so
could be considered a limiting factor
Slide 63
Rise Time or Slope Rise time is part of the inspiration so
could be considered a limiting factor It is usually not included in
the definition of a breath
Slide 64
Rise Time or Slope Rise time is part of the inspiration so
could be considered a limiting factor It is usually not included in
the definition of a breath Rise time adjusts the initial flow rate
of a breath
Slide 65
Rise Time or Slope Rise time is part of the inspiration so
could be considered a limiting factor It is usually not included in
the definition of a breath Rise time adjusts the initial flow rate
of a breath It determines how much time is allowed for the breath
to reach the peak flow needed to deliver the breath in the allotted
time (Ti)
Slide 66
Rise Time/Slope The less time the Rise time is the faster the
breath ramps up to full speed
Slide 67
Rise Time/Slope The less time the Rise time is the faster the
breath ramps up to full speed The longer the Rise Time is the
slower the breath reaches peak flow
Slide 68
Rise Time/Slope So if you have an inspiratory time of 1 second
and you set your Rise Time at 0.2 seconds the peak flow will be
reached in 0.2 seconds creating a blast of air at the beginning of
the breath
Slide 69
Rise Time/Slope So if you have an inspiratory time of 1 second
and you set your Rise Time at 0.2 seconds the peak flow will be
reached in 0.2 seconds creating a blast of air at the beginning of
the breath If you increase the Rise Time to 0.5 seconds the breath
will not reach peak flow until half way through the breath creating
a slower overall flow
Slide 70
Rise Time/Slope A short Rise Time may be helpful in patient
with high inspiratory demands, such as asthma
Slide 71
Rise Time/Slope A short Rise Time may be helpful in patient
with high inspiratory demands, such as asthma A longer Rise Time is
usually more comfortable because there is not the blast of air at
the beginning
Slide 72
Rise Time/Slope A short Rise Time may be helpful in patient
with high inspiratory demands, such as asthma A longer Rise Time is
usually more comfortable because there is not the blast of air at
the beginning Where it is set is very patient dependent
Slide 73
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath
Slide 74
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath Pressure Support Ventilation (PSV)
Slide 75
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath Pressure Support Ventilation (PSV) Flow cycling is
used to end a PSV breath
Slide 76
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath Pressure Support Ventilation (PSV) Flow cycling is
used to end a PSV breath Normal inspiration goes to zero flow and
then reverses the flow to exhale
Slide 77
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath Pressure Support Ventilation (PSV) Flow cycling is
used to end a PSV breath Normal inspiration goes to zero flow and
then reverses the flow to exhale Because it is difficult to achieve
a tight seal on the circuit and patient, it is impractical to
require the patient to get to zero flow before exhaling
Slide 78
Inspiratory Cycle Off Inspiratory cycle off is part of the flow
cycling breath Pressure Support Ventilation (PSV) Flow cycling is
used to end a PSV breath Normal inspiration goes to zero flow and
then reverses the flow to exhale Because it is difficult to achieve
a tight seal on the circuit and patient it is impractical to
require the patient to get to zero flow before exhaling Flow
cycling allow the breath to end prior to reaching zero flow
Slide 79
Inspiratory Cycle Off Some ventilators have a preset flow rate
that will cycle the PSV breath into exhalation
Slide 80
Inspiratory Cycle Off Some ventilators have a preset flow rate
that will cycle the PSV breath into exhalation Some ventilators
allow the flow rate to be adjusted
Slide 81
Inspiratory Cycle Off Some ventilators have a preset flow rate
that will cycle the PSV breath into exhalation Some ventilators
allow the flow rate to be adjusted When setting Inspiratory Cycle
Off it is a percentage
Slide 82
Inspiratory Cycle Off Some ventilators have a preset flow rate
that will cycle the PSV breath into exhalation Some ventilators
allow the flow rate to be adjusted When setting Inspiratory Cycle
Off it is a percentage The percentage is based on the peak
inspiratory flow achieved during the breath
Slide 83
Inspiratory Cycle Off Some ventilators have a preset flow rate
that will cycle the PSV breath into exhalation Some ventilators
allow the flow rate to be adjusted When setting Inspiratory Cycle
Off it is a percentage The percentage is based on the peak
inspiratory flow achieved during the breath The percent is what
determines when the breath will release the pressure and allow
exhalation
Slide 84
Inspiratory Cycle Off If you set the Inspiratory Cycle Off at
25% the inspiratory breath will end when the flow is 25% of the
peak flow during that breath
Slide 85
Inspiratory Cycle Off If you set the Inspiratory Cycle Off at
25% the inspiratory breath will end when the flow is 25% of the
peak flow during that breath If the peak flow was 60 lpm the breath
will end at 25% of that or 15 lpm
Slide 86
Inspiratory Cycle Off If you set the Inspiratory Cycle Off at
25% the inspiratory breath will end when the flow is 25% of the
peak flow during that breath If the peak flow was 60 lpm the breath
will end at 25% of that or 15 lpm The higher the % set the sooner
the breath will be cycled off
Slide 87
Inspiratory Cycle Off If you set the Inspiratory Cycle Off at
25% the inspiratory breath will end when the flow is 25% of the
peak flow during that breath If the peak flow was 60 lpm the breath
will end at 25% of that or 15 lpm The higher the % set the sooner
the breath will be cycled off This may cut off a patient breath
early