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CAPNOGRAPHY- The New Standard of Care

Introduction

Capnography is a noninvasive method for

monitoring the level of carbon dioxide in

exhaled breath.

Capnography assists clinicians diagnose

specific medical conditions, make

treatment decisions, and assess the

efficacy of resuscitation efforts and

predict outcomes

CAPNOGRAPHY

Why use it????

Applications

Endotracheal Tube Confirmation

Efficacy of CPR

Management of TBI

Assessment of Chronic and Restrictive Airway

Disease

Assessment of Perfusion

V/Q Mismatch

Global Airway Assessment

Ventilator Managment

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2010 American Heart Association Guidelines EMBARGOED FOR

RELEASE

for CPR and Emergency Cardiovascular Care Oct. 18, 12:30 a.m. EST

Comparison Chart of Key Changes

Advanced Cardiovascular Life Support (ACLS)

Continuous quantitative waveform capnography is

now recommended for intubated patients throughout

the peri-arrest period. When quantitative waveform

capnography is used for adults, applications now

include recommendations for confirming tracheal

tube placement and for monitoring CPR quality and

detecting return of spontaneous circulation based on

end-tidal carbon dioxide (Petco2) values.

ETCO2 vs. SpO2

CO2:

Relects ventilation

Detects apnea and

hypoventilation

immediately

Should be used with

pulse oximetry

O2 Saturation:

Reflects oxygenation

30 to 60 second lag

in detecting apnea or

hypoventilation

Should be used with

capnography

ETCO2 & Cardiac Resuscitation

Non-survivors

Average ETCO2: 4-10 mmHg

Survivors (to discharge)

Average ETCO2: >30 mmHg

ETCO2 & Cardiac Resuscitation

If patient is intubated and pulmonary

ventilation is consistent with bagging, ETCO2

will directly reflect cardiac output

Flat waveform can establish PEA Increasing ETCO2 can alert to return of spontaneous

circulation

Configuration of waveform will change with

obstruction

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Capnography What are we measuring?

Ventilation Physiology

Rule #1 of Life:

“Air must go in and out”

Ventilation

“The movement of air”

(Designed to Eliminate CO2 and intake O2)

Perfusion

Blood Must Circulate

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Fick Principle

Oxygen Transport

Requires:

• Adequate number of RBC’s

• Adequate O2

• RBC’s must be able to offload and upload

• Adequate blood pressure

Deadspace

Factors Affecting Tidal Volume

Hyperventilation

•TBI

•DKA

•Metabolic Acidosis

•PE

•STEMI

•Others

Hypoventilation

•CNS Disorders

•Polypharmacy OD

•TBI

•Sedation

•Narcotics

Physiological Factors Affecting

ETCO2 Levels

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Normal Arterial &

ETCO2 Values

Arterial – ETCO2 Gradient

In healthy lungs the PaCO2 to ETCO2 gradient is

2-5 mmHg

(Increase indicates V/Q mismatch)

CAPNOGRAPHY

Theory of Operation

Infrared Absorption

A beam of infrared light energy is passed

through a gas sample containing CO2

CO2 molecules absorb specific wavelengths

of infrared light energy.

Light emerging from sample is analyzed.

A ration of the CO2 affected wavelengths to

the non-affected wavelengths is reported as

ETCO2

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Capnography vs. Capnometry

Capnography:

Measurement and

display of both ETCO2

value and capnogram

(CO2 waveform)

Measured by a

capnograph

Capnometry:

Measurment and

display of ETCO2 value

(no waveform)

Measured by a

capnometer

Mainstream vs. Sidestream

Quantitative vs. Qualitative ETCO2

Quantitative ETCO2:

Provides an actual numeric

value

Found in capnographs and

capnometers

Qualitative ETCO2:

Only provides a range of values

Termed “CO2 Detectors”

Colorimetric CO2 Detectors

A “detector” – not a

monitor

Uses chemically treated

paper that changes color

when exposed to CO2

Must match color to a

range of values

Requires six breaths

before determination

can be made

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CAPNOGRAPHY

The Capnogram

End of

inspiration

Beginning of

exhalation

Alveolar

plateau

End of

exhalation

Beginning of

new breath

Clearing of anatomic dead space

1. Is there a waveform?

2. What's the baseline

3. What does the waveform look like

4. What is the CO2 measurement

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45

0

Normal range is 35-45mm Hg

4 5

0

1. Increased Rate &/or VT

2.Decreased Metabolic rate

3.Decrease in core temperature

4.Decreased cardiac output

5.Embolism (Fatty, thrombus or air)

0

4 5

1. Decreased rate &/or VT

2. Increased Metabolic rate or Cardiac Output (Rapid BP)

3. Rise in core temperature

• Malignant Hyperthermia

4. Rhabdomyolysis

5. Neural dysfunction - Widening

45

0

1. Quantitative measurement of CO2

2. Tool of Ventilation, Perfusion, Metabolism

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4 5

0

1. Complete Sudden loss of waveform*

2. Dislodgement / Apnea

3. Total obstruction

4. Equipment malfunction

4 5

0

1. Rapid descending waveform

2. Progresses to complete loss of

waveform if not corrected

40

0

1. Loss of expiratory plateau

2. Artificial airway obstruction/kink

3. Expiratory obstruction*

4. FBAO, bronchospasms

5. “Shark fin” appearance

1. Prolonged or Incomplete exhalation

2. COPD, Asthma, Bronchospasm:

• Alveoli unevenly ventilated on inspiration

• Asynchronous emptying during expiration

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COPD (Bronchitis/Emphysema), Asthma,

Bronchospasm?

Fatigue, Hypoxia, Hypercapnic =

Respiratory Distress/Arrest

40

16

1. Rebreathing (May show increase in

ETCO2)

2. Inspiratory / expiratory flow inadequate

3. Malfunctioning expiratory component –

Vent

4. Partial Rebreathing

20

16

15

0

Mean ETCO2 <10 mmHg > 20 minutes?

32

20

1.Spontaneous breathing returns

2.Emergence from blockade

3.Look at other vital signs

4. Inversely proportional to degree of blockade or

sedation

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40

20

1.Spontaneous breaths during mechanical

ventilation

2.Emergence from blockade

3. “Auto-cycling” Sensitivity setting

End Tidal (Current) x RR (Current)

End Tidal (Desired)

1. Eyes, face, neck

2. Extremities

3. Abdomen

4. Intercostals, glottis

5. Diaphragm

Order of paralysis

Sudden Loss of Waveform

Apnea

Airway Obstruction

Dislodged airway (esophageal)

Airway disconnection

Ventilator malfunction

Cardiac Arrest

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Other Methods of Acquisition

QUIZ TIME

Questions?