Ventilator graphics

Venti latorGraphics

FAY A L B UA I N A I N

Objectives:

• Introduction

• Why We Need To Know About The Ventilator Graphics ?

• Types Of Waveforms

• Types Of Breath

• Normal And Abnormal Waveforms

Introduction:

Monitoring and analysis of graphic display of curves and loops during mechanical ventilation has become critical to determine how patient is being ventilated to assess problems occurring during ventilation.

Mode function

Auto PEEP

Synchrony

TriggerWOBOver distension

PEEP

Ti

Leak

Flow cycle

Time rise

Active exhalation

Why we need to know about the ventilator graphics ?

Types Of Waveforms:

Scalars P-TF-TV-T

LoopsF-V P-V

Scalars

Types Of Waveforms:

VC-CMV SIMV+VC

PC-CMV VAP APRV SIMV+PCPSVPRVC VSV

• Constant • Sinusoidal • Ascending • Descending • Exponential

• Ascending• Sinusoidal

• Constant• Exponential

• Constant • Sinusoidal • Ascending • Descending • Exponential

• Ascending • Sinusoidal

• Constant• Exponential

VC PC

?

Time (sec)

Pre

ssu

re

(cm

H20)

Type Of Breath:

Mandatory Assisted Spontaneous

Time (sec)

Inspiration

Expiration

Pa

w (

cm H

20)

Time (sec)

Pa

w

(cm

H2O

)

Pa

w

(cm

H2O

)

Time (sec)

P-T

PIP

Transairway Pressure (PTA)} Pplateau

PEEP

Begin Inspiration Begin Expiration

AB

C

A= airway RawB= Alveolar distending pressure ABC = MAP

Respiratory Mechanics:

↑ RAW ↓ COMPLIANCE

A

B

A

B

Time rise:

Minimal Pressure Overshoot

Slow rise Moderate rise Fast rise

P

What is the benefit of the time rise ?

Inspiration

Expiration

Time (sec)

Flo

w (

L/m

in)

TI TE

F-T

Beginning of inspiration exhalation

valve closes

Peak inspiratory

flow rate PIFR

End inspiration and beginning of

expiration exhalation valve opens

Peak expiratory flow rate PEFR

Inspiration

Expiration

Time (sec)

Vo

lum

e (m

l)Inspiratory Tidal Volume

TI

V-TTidal volume

Abnormalities

ID breath type.

ID waveform type.

What is the abnormalities?

In which clinical condition we might

see these waveforms?

VC302928272625242322212019181716151413121110987654321

Increase Raw

What do these curves

indicate?

PC302928272625242322212019181716151413121110987654321

Decrease Compliance

ID breath type.

ID waveform type.

What is the abnormalities?

In which clinical condition we might

see these waveforms?

VC302928272625242322212019181716151413121110987654321

Decrease compliance

What do these curves

indicate?

302928272625242322212019181716151413121110987654321

Leak

Click icon to add picture

What do these curves

indicate?

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Inadequate Flow “ F low Starvati on”

Click icon to add picture

What do these curves

indicate?

302928272625242322212019181716151413121110987654321

Acti ve Exhalati on

Loops

P-V LOOP

Volume (mL)

Insp

iration

Expi

ratio

n

PIP

VT

Paw (cm H2O)

What does that point

indicates ?

Type Of Breath:

Controlled Assisted Spontaneous

Vol (

ml)

Paw

(cm H2O)

I

E

E

E

II

PEEP

Types Of Waveform:

PC Ps VC

WOB

Pressure (cm H2O)

Volu

me (

ml) E

I

The more vertical the loop lays, the higher the lung compliance, the more horizontal it

lays, the lower the lung compliance. Thus slope

of the line equals compliance.

The fatter the loop, the higher the airway resistance…you can

tell if it’s I or E resistance by looking

at whether the right or left side bulges out

more

F-V LOOP

Volume (ml)

PEFR

FRC

Inspiration

Expiration

Flo

w (

L/m

in)

VT

F

T

PIFR

F-V LOOP Inspiration

Expiration

Abnormalities

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Decrease compliance e.g. ARDS, atelectasis

and CHF

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Increase compliance

Leak

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Click icon to add picture

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Inadequate Sensiti vity

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Over Distension

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Increase Raw

Click icon to add picture

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Leak

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Air Trapping

What does this loop indicate?

302928272625242322212019181716151413121110987654321

I n a d e q u a te F l o w “ F l o w S ta r va ti o n ”

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Acti ve Exhalati on

Click icon to add picture

What does this loop indicate?

302928272625242322212019181716151413121110987654321

Increase Raw

Click icon to add picture

What is going on here?

302928272625242322212019181716151413121110987654321

Assessment of pressure, flow and volume waveforms is a critical tool in the management of the mechanically

ventilated patient.

References:

• Pilbeam’s Mechanical Ventilation, 5th edition.

• Curves and Loops in Mechanical Ventilation, dragger booklet.

• Handbook of Mechanical Ventilation, Kumar B Umesh, 2011.

• Maquet pocket guide,

• Ventilator Graphics and Respiratory Mechanics in the Patient With Obstructive Lung Disease, 2005.