Modes of Mechanical Ventilation

POINTS OF DISCUSSIONS

Advanced Basics: Flow and Time Limit and cycling Rise Time Volume vs Pressure Control

Mandatory Modes of Ventilation Controlled Mandatory Ventilation (CMV or IPPV)

Triggered Modes of Ventilation Continuous Positive Airway Pressure (CPAP) Pressure Support Ventilation (PSV)

Hybrid Modes of Ventilation Assist Control Mode (A/C) Synchronized Intermittent Mandatory Ventilation (SIMV)

RESPIRATORY CYCLET

rans

ition

=In

spira

tory

Cyc

ling

Transition=Expiratory Cycling

Inspiration

Expiration

MANDATORY, SPONTANEOUS AND TRIGGERED INSPIRATORY CYCLING

M

S

Tsynch

M M

M

MM

M

M

S

M

Tsupp Tsupp

Tsupp Tsupp

Tsupp

Tsupp

S

PRESSURE LIMITED BREATH

Time

Volume

Pressure Limit

EXPIRATORY FLOW CYCLING

Time

Flow

50%

100%

Flow Cycling

VOLUME CONTROLLED INFLATION

Time

Flow

Pressure

Volume

TI TE

Tidal Volume

If compliance decreases the pressure increases to maintain the same Vt

11 22 33 44 55 66

SECSEC

11 22 33 44 55 66

PPawaw

cmHcmH2200

5050

-20-20

120120

120120

SECSEC

INSPINSP

EXHEXH

FlowFlowL/minL/min

VOLUME CONTROL BREATHS

Decreased Compliance

PRESSURE CONTROLLED INFLATION

Time

Flow

Pressure

Volume

TI TE

Tidal Volume

Rise Time

Peak Inspiratory Flow

Inspiration Expiration

0 1

20

00 1 2

3

-3

0

20

021

20

00 1 2

3

-3

0

20

02

Inspiration Expiration

Volume/Flow Control Pressure Volume/Flow Control Pressure ControlControl

Time (s) Time (s)

PawPaw

Pressure

Volume

Flow

RISE TIME

Time

Flow

Pressure

Volume

TI TE

VOLUME CONTROL WITH END-INSPIRATORY PAUSE

Time

Flow

Pressure

Volume

TI TE

Tidal Volume

End Inspiratory Pause

ExpInsp

RELATIONSHIP BETWEEN TIDAL VOLUME, INSPIRATORY TIME AND FLOW

VT 1

Ti a

VT 2

VT 3

Time

Volume

Flow= 30 L/min

Flow= 15 L/min

Flow= 37.5 L/min

ExpExpInspInspInsp

RELATIONSHIP BETWEEN TIDAL VOLUME, INSPIRATORY TIME AND FLOW

VT 1

Ti a

Time

Volume

Ti b Ti c

Flow= 30 L/min

Flow= 20 L/min

Flow= 60 L/min

TRIGGERED MODES OF VENTILATION

CPAP and PSVV

SPONTANEOUS BREATHINGSPONTANEOUS BREATHING

Time (sec)Time (sec)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

CONTINUOUS POSITIVE AIRWAY PRESSURE(CPAP)

CONTINUOUS POSITIVE AIRWAY PRESSURE(CPAP)

Time (sec)Time (sec)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

CPAP Level

PRESSURE SUPPORT VENTILATION(PSV) PRESSURE SUPPORT VENTILATION(PSV)

Time (sec)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Set PS Level

Flow Cycling

Better Efforts

Longer Inspiration

Patient Triggered, Flow Cycled, Pressure limited Mode

CPAP+PSVCPAP+PSV

Time (sec)Time (sec)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Set PS Level

Flow Cycling

Patient Triggered, Flow Cycled, Pressure limited Mode

CPAP Level

TRIGGERED MODES OF VENTILATIONPRESSURE SUPPORT VENTILATION

Control Trigger Limit Target Cycle

Pressure Patient Pressure Flow

Patient Triggered Flow Cycled Ventilation

MANDATORY MODES OF VENTILATION

CMV or IPPV

MANDATORY MODES OF VENTILATIONCMV

Control Trigger Limit Target Cycle

PressureOr

Volume

Time Time

Time Triggered Time Cycled Ventilation

CONTROL MODE (PRESSURE-TARGETED VENTILATION)CONTROL MODE (PRESSURE-TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Time Triggered, Pressure Limited, Time Cycled Ventilation Time (sec)

Time CyclingSet PC Level

CONTROL MODE(VOLUME-TARGETED VENTILATION)CONTROL MODE(VOLUME-TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Time Triggered, Flow Limited, Volume Cycled Ventilation Time (sec)

Preset VT

Volume Cycling

Time Cycling

Dependent onCL & Raw

HYBRID MODES OF VENTILATION

SIMV and A/C

HYBRID MODES OF VENTILATIONA/C

Control Trigger Limit Target Cycle

PressureOr

Volume

Time Or

Patient

Time

Time or PatientTriggered Time Cycled Ventilation

ASSISTED MODE(VOLUME-TARGETED VENTILATION)ASSISTED MODE(VOLUME-TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Patient Triggered, Flow limited, Volume Cycled Ventilation Time (sec)

Preset peak Flow

Time Cycling

ASSISTED MODE (PRESSURE-TARGETED VENTILATION)ASSISTED MODE (PRESSURE-TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Patient Triggered, Pressure Limited, Time Cycled Ventilation

Time (sec)

Time CyclingSet PC Level

HYBRID MODES OF VENTILATIONSIMV/PS

Breath Type

Control

Trigger

Limit Cycle

Mandatory PressureOr

Volume

Time Or

Patient

Time

Spontaneous

Pressure Patient Pressure Flow

SIMV(VOLUME TARGETED VENTILATION)SIMV(VOLUME TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Spontaneous Breaths

M M M

Time (sec)

SIMV+PS(VOLUME TARGETED VENTILATION)SIMV+PS(VOLUME TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

MTsuppTsynch

Set PS Level

Flow-cycled

Time (sec)

SIMV + PS (PRESSURE-TARGETED VENTILATION)SIMV + PS (PRESSURE-TARGETED VENTILATION)

Flow(L/m)

Pressure(cm H2O)

Volume(mL)

Tsupp

Tsynch

Time Cycled Flow-cycled

Tsynch

Set PC Level

Set PS Level

Time (sec)

HYBRID MODE VENTILATION: SUPPRESSION

Time (sec)Time (sec)

M Tsupp MM Tsupp

M M

Tsupp Tsupp

HYBRID MODE VENTILATION: SYNCHRONIZATION(SIMV+PSV)

HYBRID MODE VENTILATION: SYNCHRONIZATION(SIMV+PSV)

Time (sec)Time (sec)

Flow(L/m)

Pressure(cm H2O)

Cycles

Triggered window for supported breaths

Triggered window for synchronized breaths

Mandatory Cycle Time

M Tsupp TsynchM Tsynch Tsupp

ALL MODES TABLES

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