1. Capnography The “Other” Vital Sign 3rd Edition
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

2. Capnography Send questions or comments to:
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This has been the third edition of the ‘Readers Digest’ version of Capnography – The ‘Other” Vital Sign. Thank you very much for spending the time and energy it took to stay awake during this presentation. Use this new found knowledge well, and in good faith. Many thanks to those supreme beings who have allowed me this opportunity to bore you silly with my senseless babbling of information on treating the sick and injured, saving life’s, and other such nonsense. Take very good care, and above all… Be safe…
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J. D’Urbano, RCP, CRT
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© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

3. Welcome to the 3rd Edition of Capnography – The “Other” Vital Sign
For many years taking your patients vital has been a standard of practice in all areas of healthcare, from pre-hospital to extended care, and everywhere in between. In today’s world of advanced medical education and technology a new vital sign is gaining popularity in patient care settings. Capnography…
In earlier years capnography was widely misunderstood by healthcare workers. It was believed by many that capnography was intended to estimate their patients’ PaCO2. That was never the intention. That misconception has earned capnography a bad-rap in almost all areas of the healthcare community. The purpose of this program is to give you a more accurate understanding of what capnography really is, what kind of information you can learn from it, and how you can use that information to better care for your patient.
Capnography refers to the study & measurement of carbon dioxide in exhaled gas. It was first introduced by a German bioengineer named Karl Luft in He used an infrared CO2 measuring device that he called URAS, which stands for “Ultra Rot Absorption Schreiber”. Directly translated it means “infrared absorption writer”. It was big, heavy, and very impractical to use in a clinical setting.
Over the years capnography evolved many times over, as did the technology used to measure it. Today that technology has proven to be so reliable that capnography is successfully used in almost all areas of healthcare.
According to a study by the American Society of Anesthesiologists 93% of all avoidable anesthesia related incidents could have been prevented with the use of capnography in conjunction with pulse oxymetry.
In 1998 the ASA (American Society of Anesthesiologists) Committee on Standards of Care deemed it mandatory that all patients receiving general anesthesia be continuously monitored for ETCO2.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

4. Capnography
Capnography refers to the study and measurement of carbon dioxide in exhaled gas.
Capnography was first introduced by Karl Luft, a German bioengineer, in 1943 with an infrared CO2 (carbon dioxide) measuring device he called URAS, or “Ultra Rot Absorption Schreiber” (Infrared Absorption Writer)
It was big, heavy, and very impractical to use.
Over the years capnography evolved many times, as did the technology used to measure it.
According to a study by the American Society of Anesthesiologists 93% of all avoidable anesthesia related incidents could have been prevented with the use of capnography in conjunction of pulse oxymetry.
In 1998 the ASA (American Society of Anesthesiologists) Committee on Standards of Care deemed it mandatory that all patients receiving general anesthesia be continuously monitored for ETCO2 (End Tidal Carbon Dioxide)
Today capnography is successfully used in almost all areas of health care.
Capnography refers to the study & measurement of carbon dioxide in exhaled gas. It was first introduced by a German bioengineer named Karl Luft in He used an infrared CO2 measuring device that he called URAS, which stands for “Ultra Rot Absorption Schreiber”. Directly translated it means “infrared absorption writer”. It was big, heavy, and very impractical to use in a clinical setting.
Over the years capnography evolved many times over, as did the technology used to measure it. Today that technology has proven to be so reliable that capnography is successfully used in almost all areas of healthcare.
According to a study by the American Society of Anesthesiologists 93% of all avoidable anesthesia related incidents could have been prevented with the use of capnography in conjunction with pulse oxymetry.
In 1998 the ASA (American Society of Anesthesiologists) Committee on Standards of Care deemed it mandatory that all patients receiving general anesthesia be continuously monitored for ETCO2.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

5. Capnography
Carbon dioxide (CO2), one of the waste products of cell metabolism, is created as we burn glucose and oxygen to produce energy in the form of adenosine triphosphate (ATP).
The excess CO2 is carried by the blood to the lungs where it leaves the body during the expiratory phase of respiration.
After the expiratory phase is complete the inspiratory phase begins, we take in more oxygen, and that part of the metabolic cycle begins again.
There is significance in not only the concentration of CO2 measured at the end of the expiratory phase, but also in comparison to the concentration of CO2 in arterial blood.
Carbon dioxide is one of the waste products of cell metabolism. It is created as we burn glucose and oxygen to produce energy in the form of adenosine triphosphate (ATP). The excess CO2 is carried in blood plasma of the venous system to the lungs where it is expelled from the body through the lungs during the exhalation phase of respiration.
At the end of the expiratory phase the inspiratory phase takes place and oxygen is taken in and delivered to the body and this part of the metabolic cycle begins again.
There is clinical significance in not only the concentration of CO2 measured at the end of the expiratory phase, but also in comparison to the concentration of CO2 dissolved in blood plasma of arterial blood.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

6. Capnography Definitions
Capnography – A graphical display of CO2 concentration over time or expired volume.
Capnogram – CO2 waveform either plotted against a volume (CO2 expirogram) or against time (time capnogram).
PACO2 – Partial pressure of carbon dioxide in the alveoli.
PaCO2 – Partial pressure of carbon dioxide in arterial blood.
PETCO2 – Partial pressure of carbon dioxide at the end of expiration.
P(a-ET)CO2 – The difference between PaCO2 and PETCO2. Sometimes called the “CO2-diff”, or “CO2 gradient”.
PVCO2 – Partial pressure of carbon dioxide in mixed venous blood.
Definitions
Capnography – A graphical display of CO2 concentration over time or expired volume.
Capnogram – CO2 waveform either plotted against a volume (CO2 expirogram) or against time (time capnogram).
PACO2 – Partial pressure of carbon dioxide in the alveoli.
PaCO2 – Partial pressure of carbon dioxide in arterial blood.
PETCO2 – Partial pressure of carbon dioxide at the end of expiration.
(a-ET)PCO2 – The difference between PaCO2 and PETCO2. Also shown as P(a-ET)CO2. Sometimes called the “CO2-diff”, or “CO2 gradient”.
PVCO2 – Partial pressure of carbon dioxide in mixed venous blood.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

7. Capnography
To understand capnography you MUST understand that “Oxygenation” and “Ventilation” are two entirely different mechanisms that both rely on the respiratory cycle.
Oxygenation relies on the inspiratory phase and refers to the amount of oxygen (O2) available and utilized.
Ventilation relies on the expiratory phase and refers to the amount of carbon dioxide (CO2) produced during the metabolic cycle of the cells, and exhaled from the body.
Oxygenation and ventilation are BOTH needed, in proper proportion, to sustain an adequate and safe quality of life.
To understand capnography it must be understood that oxygenation and ventilation are two entirely different mechanisms. Although they are completely unrelated to each other they both rely on the respiratory cycle.
Oxygenation relies on the inspiratory phase of respiration and refers to the amount of oxygen available and utilized.
Ventilation relies on the expiratory phase of respiration and refers to the amount of carbon dioxide produced during the metabolic cycle of the cells, and exhaled from the body.
Oxygenation and ventilation are both needed in proper proportion to sustain an adequate and safe quality of life.
Oxygenation and ventilation are both needed to function properly to sustain life.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

8. Capnography
Oxygenation: The amount of oxygen taken in by the lungs and made available to the cells. Oxygenation relies on the inspiratory phase of the respiratory cycle. There are at lease two ways to check a patients oxygenation status; Invasively an arterial blood gas (ABG) can be obtained which measures, among other things, the PaO2 (Partial Pressure of Oxygen dissolved in the blood plasma of arterial blood). Non-Invasively a pulse oxymetry can be obtained which measures the amount of oxygen that is bound to the hemoglobin.
Oxygenation: The amount of oxygen taken in by the lungs and made available to the cells. Oxygenation relies on the inspiratory phase of the respiratory cycle. There are at lease two ways to check a patients oxygenation status;
Invasively an arterial blood gas can be obtained which measures, among other things, the PaO2 (Partial Pressure of Oxygen dissolved in the blood plasma of arterial blood).
Non-Invasively a pulse oxymetry can be obtained which measures the amount of oxygen that is bound to the hemoglobin.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

9. Capnography
Ventilation refers to the amount of carbon dioxide in arterial blood and expelled from the body through exhalation. Ventilation relies on the expiratory phase of the respiratory cycle, and can be measured in two ways. Invasively the same arterial blood gas (ABG) sample that measures the PaO2 also measures the PaCO2 (Partial Pressure of carbon dioxide dissolved in blood plasma of arterial blood). Non-Invasively the PETCO2 (Partial pressure of carbon dioxide in exhaled gas) can be measured. This is measured breath by breath at the end of the expiratory phase.
Ventilation refers to the amount of carbon dioxide in arterial blood and expelled from the body through exhalation. Ventilation relies on the expiratory phase of the respiratory cycle, and can be measured in two ways.
Invasively the same arterial blood gas sample that measures the PaO2 also measures the PaCO2 (Partial Pressure of carbon dioxide dissolved in blood plasma of arterial blood).
Non-Invasively the PETCO2 (Partial pressure of carbon dioxide in exhaled gas) can be measured. This is measured breath by breath at the end of the expiratory phase.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

10. Capnography
Pre-Hospital – Paramedics frequently use carbon dioxide detection devices to assist them in assuring an endotracheal tube is properly placed.
Emergency Medicine – Capnography is frequently used to assure proper ET tube placement, trend for adequate ventilation during mechanical ventilation, and that the heart rhythm on the monitor is not PEA.
Critical Care Medicine – In the ICU capnography can be used to trend ventilation during mechanical ventilation, watch for changes in dead space ventilation, and watch the progress of many pulmonary related disease processes.
Cardiopulmonary Arrest – During CPR capnography can be used as a predictor of survivability, to check for adequate cardiac output during chest compressions, and as an indicator of PEA if a heart rhythm return on the monitor.
Procedural Sedation – During conscious sedation capnography is a much faster indicator of changes in respiratory status than pulse-oxymetry. It can take several minutes for SaO2 to change, but ETCO2 changes almost immediately.
Anesthesia – Capnography in the OR has been a standard of care since It is used to maintain adequate ventilation, watch for drastic changes in dead space ventilation, and assure the presence of adequate cardiac output during surgery.
Capnography is successfully used in almost all area of healthcare including;
Pre-Hospital – Paramedics frequently use carbon dioxide detection devices to assist them in assuring an endotracheal tube is properly placed.
Emergency Medicine – Capnography is frequently used to assure proper ET tube placement, trend for adequate ventilation during mechanical ventilation, and that the heart rhythm on the monitor is not PEA.
Critical Care Medicine – In the ICU capnography can be used to trend ventilation during mechanical ventilation, watch for changes in dead space ventilation, and watch the progress of many pulmonary related disease processes.
Cardiopulmonary Arrest – During CPR capnography can be used as a predictor of survivability, to check for adequate cardiac output during chest compressions, and as an indicator of PEA if a heart rhythm return on the monitor.
Procedural Sedation – During conscious sedation capnography is a much faster indicator of changes in respiratory status than pulse-oxymetry. It can take several minutes for SaO2 to change, but ETCO2 changes almost immediately.
Anesthesia – Capnography in the OR has been a standard of care since It is used to maintain adequate ventilation, watch for drastic changes in dead space ventilation, and assure the presence of adequate cardiac output during surgery.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

11. Capnography Methods of Monitoring Methods of Monitoring
There are several methods used to detect and monitor carbon dioxide in gas or blood.
Infrared Spectrography – Most commonly used in the hospital setting
Raman Spectrography
Mass Spectrography
Photo-acoustic Spectrography
Molecular Correlation Spectrography (Microstream technology)
Chemical Colorimetric Analysis – Most commonly used in the pre-hospital setting
Methods of Monitoring
There are several methods used to detect and monitor carbon dioxide in gas or blood.
Infrared Spectrography – This is the method that is most commonly used in the hospital setting.
Raman Spectrography
Mass Spectrography
Photo-acoustic Spectrography
Molecular Correlation Spectrography (Microstream technology)
Chemical Colorimetric Analysis – This is most commonly used in the pre-hospital and medical emergency settings.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

12. Infrared Spectrography
Capnography
Infrared spectrography works on the principal that carbon dioxide selectively absorbs a known amount of infrared light of a specific wavelength (4.3 milli-microns). The amount of light absorbed is directly proportional to the concentration of carbon dioxide molecules. A predetermined amount of infrared light is sent from the emitting side of the sensor through a gas sample and collected on the receiving side of the sensor (the receiving side of the CO2 sensor is an IR detector). The infrared light received is compared to the infrared light transmitted. The difference is then converted by calculations into the partial pressure that you see on the monitor. Some models also calculate the difference into a percentage of total gas concentration.
Infrared Spectrography
Infrared spectrography works on the principal that carbon dioxide selectively absorbs a known amount of infrared light of a specific wavelength (4.3 milli-microns). The amount of light absorbed is directly proportional to the concentration of carbon dioxide molecules. A predetermined amount of infrared light is sent from the emitting side of the sensor through a gas sample and collected on the receiving side of the sensor (the receiving side of the CO2 sensor is an IR detector). The infrared light received is compared to the infrared light transmitted. The difference is then converted by calculations into the partial pressure that you see on the monitor. Some models also calculate the difference into a percentage of total gas concentration.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

13. Chemical Colorimetric Analysis
Capnography
Chemical colorimetric analysis uses a pH-sensitive chemical indicator inside a device that is placed between an endotracheal tube and a breathing circuit, such as a manual respirator or a ventilator circuit. This indicator changes color breath by breath. It turns yellow when it’s exposed to a carbon dioxide concentration of 4% or greater, and purple when it’s exposed to room air that contains no carbon dioxide.
These devices are good for quick determination of the presence of CO2 but are not sensitive to low concentrations of CO2, as is the case during CPR or other low cardiac output situations.
There are also several circumstances which can cause false positive results…
Chemical Colorimetric Analysis
CO2 Not Present
Chemical colorimetric analysis uses a pH-sensitive chemical indicator inside a device that is placed between an endotracheal tube and a breathing circuit, such as a manual respirator or a ventilator circuit. This indicator changes color breath by breath. It turns yellow when it’s exposed to a carbon dioxide concentration of 4% or greater, and purple when it’s exposed to room air that contains no carbon dioxide.
These devices are good for quick determination of the presence of CO2 but are not sensitive to low concentrations of CO2, as is the case during CPR or other low cardiac output situations.
There are also several circumstances which can cause false positive results…
CO2 Present
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

14. The 2 Types of Capnometers
Capnography
The 2 Types of Capnometers
Mainstream
Sidestream
There are 2 types of capnometers; Mainstream and Sidestream.
Mainstream capnometers use a sensor that is in the direct path of the gas source and is connected to the monitor by an electrical wire.
Sidestream capnometers use a 6 foot length of thin tubing and a lightweight airway adapter. A gas sample is continuously aspirated from the patient via the airway adapter and to the sensor which is located inside the monitor. Optimally the gas flow should be at a rate of 50 – 200 ml/min but some models aspirate at a rate as high as >400 ml/min, making them a poor choice for neonatal patients.
The infrared sensor is in the direct path of the gas source, and connected to the monitor by an electrical wire.
The sample of gas is aspirated into the monitor via a lightweight airway adapter and a 6ft length of tubing. The actual sensor is inside the monitor.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

15. Mainstream – Advantages
Capnography
Mainstream – Advantages
Mainstream
NO sampling tube to become obstructed.
No variation due to barometric pressure changes.
No variation due to humidity changes.
Direct measurement means waveform and readout are in ‘real-time’. There is no sampling delay.
Suitable for pediatrics and neonates.
Mainstream Capnography – Advantages
No sampling tube to become obstructed.
No variation in measurement due to barometric pressure changes.
No variation in measurement due to changes in humidity.
Because mainstream capnography is a direct measurement (the capnography sensor is directly in the path of the exhaled gas)the waveform and readout are in “real-time”. There is no sampling delay.
Mainstream capnography is suitable for adults, pediatrics, and neonates.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

16. Mainstream – Disadvantages
Capnography
Mainstream – Disadvantages
Mainstream
The airway adapter sensor puts weight at the end of the endotracheal tube that often needs to be supported.
In older models there were minor facial burns reported.
The sensor windows can become obstructed with secretions and water rainout.
Sensor and airway adapter can be positional – difficult to use in unusual positions (prone, etc).
Mainstream Capnography – Disadvantages
The airway adapter/sensor is attached between the endotracheal tube and ventilator circuit. This puts added weight at the end of the endotracheal tube and often needs to be supported.
In older models the sensors were heated to a higher temperature than models of today. Some minor burns were reported.
The sensor “windows” can become obstructed with secretions and water rainout.
The airway adapter/sensor can be positional, making it difficult to use in unusual positions. (prone, rotobed, etc…)
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

17. Sidestream – Advantages
Capnography
Sidestream – Advantages
Sampling capillary tube and airway adapter is easy to connect.
Single patient use sampling – No issues with sterilization.
Can be used with patient in almost any position (prone, etc…).
Can be used on awake patients via a special nasal cannula.
CO2 reading is unaffected by oxygen flow through the nasal cannula.
Sidestream – Advantages
Sampling airway tubing and airway adapter is easy to connect.
Single patient use sampling means there is no issue with cross-contamination or sterilizing adapters.
Airway adapters are useful in almost any position, making them a good tool for patients in a prone position or on a roto-bed.
Can be used with patients who are awake and not intubated via a special nasal cannula.
The CO2 readout is unaffected by the flow of oxygen through the nasal cannula.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

18. Sidestream – Disadvantages
Capnography
Sidestream – Disadvantages
The sampling capillary tube can easily become obstructed by water or secretions.
Water vapor pressure changes within the sampling tube can affect CO2 measurement.
Waveforms of children are often not clear, deformed.
Delay in waveform and readout due to the time it takes the gas sample to travel to the sensor within the unit.
Sidestream – Disadvantages
The sampling capillary tube can easily become obstructed by secretions or water.
Water vapor pressure changes within the capillary tube can affect the CO2 measurement.
Waveforms of small children are often deformed or unclear.
Due to the time it takes gas to travel through the sampling capillary tubing to the sensor (which is inside the unit) there is a significant delay between breaths and the waveform and readout.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

19. Capnography The Capnogram
Phase-I is the onset of expiration which contains only deadspace gas of the upper airway.
Phase-II is the upward slope that contains a mixture of deadspace gas and alveolar gas.
Phase-III, also called the alveolar plateau, contains only alveolar gas.
Phase-0 is the onset of inspiration.
The Capnogram – Current Terminology
Phase-I is the onset of expiration which contains only deadspace gas of the upper airway.
Phase-II is the upward slope that contains a mixture of deadspace gas and alveolar gas.
Phase-III, also called the alveolar plateau, contains only alveolar gas.
Phase-0 is the onset of inspiration.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

20. Capnography The Capnogram
The alpha-angle is the angle between Phase-II and Phase-III of the capnogram. A decreased alpha-angle can indicate partial airway obstructions or V/Q mismatching.
The beta-angle is the angle between Phase-III and Phase-0 of the capnogram. A decreased beta-angle can indicate CO2 rebreathing
The alpha-angle is the angle between Phase-II and Phase-III of the capnogram. A decreased alpha-angle can indicate partial airway obstructions or V/Q mismatching.
The beta-angle is the angle between Phase-III and Phase-0 of the capnogram. A decreased beta-angle can indicate CO2 rebreathing
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

21. Capnography The Capnogram
The presence of Phase-IV on a capnogram indicates an unequal emptying between the left and right lung. This can be caused by a unilateral bronchospasm, or a partial airway obstruction within the left or right bronchial tree.
The Capnogram – The Presence of Phase-IV
The presence of Phase-IV on a capnogram indicates an unequal emptying between the left and right lung. This can be caused by a unilateral bronchospasm, or a partial airway obstruction within the left or right bronchial tree.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

22. Capnography
Normal values for PETCO2 is 30 – 40 mmHg. This is for the text-book patient; 35 year, 6 foot, 165 pound, white male in perfect health.
In the clinical setting normal PETCO2 is considered to be 3 – 5 mmHg below the PaCO2 via arterial blood gas measurement.
This calculated measurement is the P(a-ET)CO2, also called the CO2-diff, or the CO2 gradient.
The P(a-ET)CO2 is directly proportional to the amount of dead-space ventilation (Ventilation that does not participate in gas exchange).
There is clinical significance in both measurements – The PETCO2 and the P(a-ET)CO2.
There are numerous conditions and circumstances, acute and chronic, that will effect the PETCO2 measurement and the P(a-ET)CO2 measurement. See the tables on the following slides…
Normal values for PETCO2 is 30 – 40 mmHg. This is for the text-book patient; 35 year, 6 foot, 165 pound, white male in perfect health.
In the clinical setting normal PETCO2 is considered to be 3 – 5 mmHg below the PaCO2 via arterial blood gas measurement.
This calculated measurement is the P(a-ET)CO2, also called the CO2-diff, or the CO2 gradient.
The P(a-ET)CO2 is directly proportional to the amount of dead-space ventilation (Ventilation that does not participate in gas exchange).
There is clinical significance in both measurements – The PETCO2 and the P(a-ET)CO2.
There are numerous conditions and circumstances, acute and chronic, that will effect the PETCO2 measurement and the P(a-ET)CO2 measurement. See the tables on the following slides…
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

23. Capnography Increased PETCO2: Decreased PETCO2:
Decreased Alveolar Ventilation
Decreased respiratory rate
Decreased tidal volume
Increased equipment deadspace
Increased Alveolar Ventilation
Increased respiratory rate
Increased tidal volume
Increased CO2 Production
Fever
Hypercatabolic state
Reduced CO2 Production
Hypothermia
Hypocatabolic state
Increased Inspired CO2
Rebreathing
CO2 absorber exhausted
External source of CO2
Increased Alveolar Deadspace
Decreased cardiac output
Pulmonary embolism
High positive end-expiratory pressure (PEEP) during positive pressure ventilation
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

24. Capnography Increased E(a-ET)CO2: Decreased E(a-ET)CO2: Emphysema
Pulmonary embolism
Low cardiac output states
Hypovolemia
Slightly increases with age
Can occur during pregnancy
Occurs naturally in young children
Young children and infants normally have less dead-space ventilation than adults because their lungs and airways are much smaller in size
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

25. Capnography
The above image is a graphical representation of alveolar and deadspace ventilation based on the PETCO2 capnogram.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

26. Capnography
Capnography is a very fast indicator of many problems that can arise during artificial ventilation.
In most cases capnography responds much faster than pulse-oximetry, which can sometimes take 3 – 4 minutes to show a change in respiratory status.
The measured ETCO2 alone, while important, is of limited value. In many cases it is the waveform that tells you a lot more about the pulmonary and airway status of your patient.
Capnography is a very fast indicator of many problems that can arise during artificial ventilation.
In most cases capnography responds much faster than pulse-oximetry, which can sometimes take 3 – 4 minutes to show a change in respiratory status.
The measured ETCO2 alone, while important, is of limited value. In many cases it is the waveform that tells you a lot more about the pulmonary and airway status of your patient.
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

27. Capnography Sudden Loss of PETCO2 Airway disconnected ET Tube kinked
ET Tube dislodged
Airway obstruction
Ventilator malfunction
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

28. Consistently low PETCO2
Capnography
Consistently low PETCO2
Alveolar hyperventilation
Hypothermia
Increased dead space ventilation
Sedation / Anesthesia
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

29. Capnography Sudden High PETCO2 Alveolar hypoventilation
Inadequate minute volume
Hyperthermia, pain, shivering
Respiratory depressant lungs
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

30. Rising alveolar plateau (Notice the increased alpha-angle)
Capnography
Rising alveolar plateau (Notice the increased alpha-angle)
Bronchospasm
Mucus plugging
Partial airway obstruction
Partially kinked ET tube
Prolonged expiratory phase
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

31. Rapidly Decreasing PETCO2
Capnography
Rapidly Decreasing PETCO2
Onset of cardiopulmonary arrest
Developing pulmonary embolus
Increasing dead space ventilation
Sudden hypotension / blood loss
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

32. Capnography Rapidly Rising PETCO2 Rising body temperature
Increased metabolism
Progressing alveolar hypoventilation
Partial airway obstruction
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

33. Rapidly Decreasing PETCO2
Capnography
Rapidly Decreasing PETCO2
Onset of cardiopulmonary arrest
Developing pulmonary embolus
Increasing dead space ventilation
Sudden hypotension / blood loss
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

34. Capnography
This has been the 3rd edition of the ‘Readers Digest’ version of Capnography – The ‘Other” Vital Sign. Thank you very much for spending the time and energy it took to stay awake during this presentation. Use this new found knowledge well, and in good faith. Many thanks to those supreme beings who have allowed me this opportunity to bore you silly with my senseless babbling of information on treating the sick and injured, saving lives, and other such nonsense. Take very good care, and above all… Be safe…
Send questions or comments to:
J. D’Urbano, RCP, CRT
Visit Our Website:
Join Our Forum: (Always FREE)
This has been the third edition of the ‘Readers Digest’ version of Capnography – The ‘Other” Vital Sign. Thank you very much for spending the time and energy it took to stay awake during this presentation. Use this new found knowledge well, and in good faith. Many thanks to those supreme beings who have allowed me this opportunity to bore you silly with my senseless babbling of information on treating the sick and injured, saving life’s, and other such nonsense. Take very good care, and above all… Be safe…
Send questions or comments to:
J. D’Urbano, RCP, CRT
Visit Our Website:
Join Our Forum: (Always FREE)
© 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition

35. Capnography The “Other” Vital Sign © 2010 – J. D’Urbano, RCP, CRT
Capnography – The “Other” Vital Sign – 3rd Edition