Bilgrami, Irma — Reading the Vent Like an ECG

Reading the Ventilator Like An ECG

OBJECTIVES SYSTEMIncorporate ventilator information in patient assessment

Course in mechanical ventilation

Advanced course in ventilator waveform analysis

Respiratory physiology

WHAT IS NORMAL- in brief

HAVE A SYSTEM- like an ECG

CASE STUDIES

What is normal???

VentilatorsAlarmsVentilator graphics

PRESSURE

FLOW

VOLUME

VENTILATOR GRAPHICS

WAVEFORMS

LOOPS

Pressure vs volumeFlow Vs Volume

Volume ModeP

CmH20

30

20

10

0

Flow L/min

80

40

0

-40

Vtmls

300

200

100

0

Time(s)

Time(s)

Time(s)

A

B

C

a

b c

d

e f

Time

Time

Time

Pressure Mode

Volume

Pressure

Flow

Inspiration Expiration

Flow wave form = Decelerating

Affected by changes in compliance/ resistance

Pressure waveform= rectangular

Not affected by change in compliance/ resistance

VOLUME mode

Descending Ramp Flow Pattern

THIS TALK

Have a System

A) Patient AssessmentReport ECG findingsDesc

ribeInterpret

Patient Assessment

B) Technical quality

C) Report Ventilator findings


ribeInterpret

Patient Assessment

Oxygen Saturations

End Tidal CO2 Trace

Haemodynamics

B) Technical qualityReport ECG findingsDesc

ribeInterpret

Patient Assessment

Know your ventilator

..and the alarms

C) Report Ventilator findingsReport ECG findingsDesc

ribeInterpret

Patient Assessment

1) Mode?

2) Parameters set and achieved?

4) Interpretation?

3) Information from waveforms/manoeuvres ?

3) Report Ventilator findings

VOLUME mode

Volume set, pressure variable

Pressure mode

Pressure set, volume variable

1) Mode?

2) Parameters set


VolumeRespiratory rate

Inspiratory Flow RateInspiratory Time

FIO2PEEP

2) Parameters achieved

Peak Pressure

Volume-expiratory

I:E ratio achieved

3) Information from waveforms/manoeuvres


Influenced by ComplianceResistanceFlow pattern

Values

Pattern

Curve meet baseline

VOLUME MODE

Values

Pattern

Peak pressure

? Problem with

airway resistance or lung compliance

HIGH AIRWAY PRESSURES

Inspiratory Hold ManoeuvreAssess Plateau Pressure

HIGH PLATEAU PRESSURESLow complianceGas trapping

Expiratory Hold ManoeuvreAssess Auto-PEEP

Values

PIFR

Values

Pattern

Expiratory flow reaches baseline well before expiratory time has ended

AUC

PEFR

Pattern

VOLUME MODE

Set by the userDecelerating Square

Not affected by change in lung characteristics

Values

Pattern

Tidal volume

Values

Pattern

Return to baseline

VOLUME MODE

time

4) Interpretation?

C) Report Ventilator findings

Safe ventilation?TV 6-8ml/kgPplat<30

Safe oxygenation?FiO2<60%

Other problems:Low Compliance

High Resistance


ribeInterpret

Patient Assessment

B) Technical qualityC) Report Ventilator findings

1) Mode?


4) Interpretation?


Safe ventilation?Safe oxygenation?Other problems

If you change the ventilator settings

REASSESS the patient

New Admissions overnightMatt: Drug overdose

Rosa: Severe pneumonia

Ms Smith: Asthma

Morning Ward Round

Matt24yr old man

Drug overdose

24year old manBenzodiazepine overdose

Currently intubated/ ventilated

Weight 70 kg (predicted body weight)

History

Examination

Examination

INFUSIONS:

Propofol 100mg/hour

PHYSICAL EXAM

ETT Size 8.5Minimal secretionsUnremarkable exam

Investigations

Ventilator

What mode

Parameters set and achievedOxygenationVentilation

Interpretation

Waveforms

MODE Parameters set

The Ventilator

Parameters achieved

Information from waveforms

The Ventilator

INTERPRETATION

IS VENTILATION SAFE?

IS OXYGENATION SAFE?

Other ISSUES?



Other problems:Low ComplianceHigh Resistance

I:E ratio of 1:1


ribeInterpret

Patient Assessment


1) Mode?


4) Interpretation?



Morning Ward Round

ROSA36yr Lady

Pneumonia

PROBLEM WITH LUNG COMPLIANCE?

Lung parenchymaPleuraChest wall

PRESSURE TIME CURVEVolume mode

Values

Pattern

Increased PIP

Same shape. Higher pressures

Values

Pattern

Expiratory limb back to baseline

FLOW TIME CURVEVolume mode

Values

Pattern

Increased Expiratory flow rate

Flow pattern normalArea under curve same in bothCurve finishes earlier

Values

Pattern

No Change

HISTORY

Rosa, 36 year old lady with respiratory failure 2’ to Community acquired pneumonia

Day 1 ICU

Weight= 80 Kg (Predicted body weight)

History

INFUSIONS:

Morphine 10mg/hrMidazolam: 10mg/hrNoradrenaline : 5 mcg/min

EXAM

PHYSICAL EXAM

ETT Size 8Purulent secretionsCoarse creps , reduced air entry

Investigations

PHYSICAL EXAM

ETT Size 8Purulent secretionsCoarse creps , reduced air entry

ABG

pH 7.33PaCo2 57PaO2 65HCO3 24BE 0

Sats 85%

Ventilator

What mode


Interpretation

Waveforms

MODEParameters set

The Ventilator

Parameters achieved


FT

The Ventilator

IncreasePeak pressure? Plateau pressure

IncreaseExpiratory flow rate

Inspiratory pause Expiratory pause

INTERPRETATION

Severe respiratory failure with P/F ratio of 65Poor lung compliance, with high plateau pressures



Other ISSUES?




MANAGE Patient

MANAGE Ventilator

PositionSedate / ParalyseFluid balance

Lung protective ventilationOptimum PEEP

Consider rescue treatments


ribeInterpret

Patient Assessment


1) Mode?


4) Interpretation?



Morning Ward Round

Ms Smith35yr old

Exacerbation of Asthma

PROBLEM WITH Resistance?

ET tubeIncreased airways resistance

PRESSURE TIME CURVEIncreased Airway Resistance

Values

Pattern

Increased PIP

Rapid rise in PIP. Then tapers down

Values

Pattern

Expiratory limb back to baseline

VOLUME MODE

Values

Pattern

FLOW TIME CURVEIncreased Airway Resistance

Values

Pattern

Decreased Expiratory flow rate

Increased expiratory timeRises to zero baseline just before next breath

VOLUME MODE

FLOW TIME CURVEAuto-PEEP

Values

Pattern

Decreased Expiratory flow rate

Increased expiratory timeDoes not reach baselineAUC exp< inp

VOLUME MODE

Values

Pattern

No Change

35 year old lady with respiratory failure 2’ to exacerbation of Asthma

Currently intubated

Weight 80kg (Predicted body weight)

History

Examination

Examination

INFUSIONS:

Morphine 10mg/hrMidazolam: 10mg/hrNoradrenaline : 2 mcg/min

PHYSICAL EXAM

ETT Size 8.5Trachea midlineB/L expiratory wheeze

Investigation

Ventilator

What mode


Interpretation

Waveforms

MODE

The Ventilator

Parameters achieved

15

Parameters set


The Ventilator

IncreaseEarly Peak pressures

DECREASEExpiratory flow rate

INCREASEExpiratory time

Inspiratory pause

Expiratory pause

Raised Peak pressure

Plateau pressure normal

No intrinsic PEEP

PcmH20

Time

INTERPRETATION



Other problems?




INCREASED AIRWAY RESISTANCENO gas trapping

MANAGE Patient

MANAGE Ventilator

BronchodilatorsSteroidsAntibiotics

Monitor for gas trap

Emergency buzzer

PHYSICAL EXAM

Trachea midlineDiminished breath sounds

Parameters achieved

Parameters set

MODE

Volume mode

F 18, TV 500, Flow 70, FiO2 35%, PEEP 0

Peak pressure 55, I:E 1:4, Volume 430

Expiratory pause

INTERPRETATION



Other Problems?

Gas trapping



Other problems:Low ComplianceHigh ResistanceDyssynchronyEquipment

MANAGE Patient

MANAGE Ventilator

Disconnect patient Consider and correct

Hypovolemia, Pneumothorax

Disconnect patient.

Decreased RRIncrease Insp flow rateProlonged I:E


ribeInterpret

Patient Assessment


1) Mode?


4) Interpretation?



Read Ventilator – daily patient assessmentHave a System

Modes of Ventilation

Loops

Dyssynchrony

Waveform abnormalities

PEEP/ Recruitment


ribeInterpret

Patient Assessment


1) Mode?


4) Interpretation?



8th Alfred Advanced Mechanical Ventilation Conference (AAMVC) Waveforms Workshop & Physiotherapy MeetingWednesday, 16 July, 2014 - Friday, 18 July, 2014

ReferencesCritical Care Medicine Tutorialshttp://www.ccmtutorials.com/rs/mv/

Puritan Bennett™ , 840 Ventilator, User’s Pocket Guidehttp://www.covidien.com/imageServer.aspx/doc228227.pdf?contentID=26430&contenttype=application/pdf

Curves and loops in mechanical ventilationhttp://www.draeger.net/media/10/08/41/10084127/rsp_curves_and_loops_booklet_9097339_en.pdf

http://lifeinthefastlane.com/education/ccc/pressure-vs-time-graph/

Oh's Intensive Care Manual, 6eAndrew D Bersten, Neil Soni

http://www.ccmtutorials.com/rs/mv/

http://www.covidien.com/imageServer.aspx/doc228227.pdf?contentID=26430&contenttype=application/pdf

http://www.draeger.net/media/10/08/41/10084127/rsp_curves_and_loops_booklet_9097339_en.pdf

http://lifeinthefastlane.com/education/ccc/pressure-vs-time-graph/

Report ECG findingsDesc

ribeInterpret

Patient Assessment

THANK YOU

Bilgrami, Irma — Reading the Vent Like an ECG

Health & Medicine

Transcript of Bilgrami, Irma — Reading the Vent Like an ECG