Capnography

1. Re-appropriated
from the internet by
Diane J. Morris

2. Objectives
• Understand why we use capnography
• Understand the physiology of respiration/ ventilation
• Define normal & abnormal EtCO2 values/ waveforms
• Understand the 4 major applications of EtCO2
– intubated applications (mainstream)
– non-intubated applications (sidestream)

3. Why Capnography?
Advanced Airway Management
All devices used to confirm tube placement must be documented on the
PCR.
• Esophageal Detection Device (EDD)
• End tidal CO2 detector (ETCO2) colorimetric or capnography
“Conclusion: No unrecognized misplaced intubations were found in
patients for whom paramedics used continuous EtCO2 monitoring.
Failure to use continuous EtCO2 monitoring was associated with a
23% unrecognized misplaced intubation rate.
[Annals of Emergency Medicine 2005; 45:497-503]”

4. Why Capnography?
• Verification of proper tube placement
There is simply NO BETTER WAY to confirm proper tube placement
than with waveform capnography…. PERIOD!!!

5. Why Capnography?
Because respiration, ventilation and oxygenation are
VERYVERYdifferent concepts.

6. Why Capnography?
It’s a window into the patient’s ventilatory status

7. Why Capnography?
Core Concepts
• What intubation verification method is most reliable?
• How do oxygenation and ventilation differ?

8. Physiology

9. Factors that affect CO2 levels:
INCREASE IN ETCO2 DECREASE IN ETCO2
Increased muscular activity Decreased muscular activity
Increased cardiac output
(during resuscitation)
Decreased cardiac output
(during resuscitation)
Effective drug therapy for
bronchospasm
Bronchospasm
Hypoventilation Hyperventilation

10. Normal EtCO2

11. Terminology
Capnogram
a real-time waveform record of the
concentration of carbon dioxide in the
respiratory gases
Capnograph
Capnogram waveform plus
numerical value

12. Terminology
EtCO2 – End Tidal CO2
The measurement of exhaled CO2 in the breath
Normal Range 35-45 mmHg

13. Normal Waveform
End of
inspiration
Beginning of
exhalation
End of
exhalation
Beginning of
new breath
Alveolar
plateau
Clearing of anatomic dead space

14. Normal
Common Waveforms

15. Hyperventilation
Hypoventilation
Common Waveforms

16. 4 Main Uses of Capnography
• Severity of asthma patients
• Monitoring head injured patients
• Cardiac arrest
• Tube confirmation

17. Terminology
Sidestream
An indirect method of measuring exhaled CO2 in non-intubated patients
Mainstream
Direct method of measuring exhaled CO2 with intubated patients

18. Shark Fin
Asthmatic Waveforms
COPD patients have a difficult time exhaling gases
This is represented on the capnogram by a shark fin appearance

19. Moderate Attack
Mild Attack
EtCO2 & Asthma

20. Severe Attack
EtCO2 & Asthma
Time To Get MOVING!!!
The asthmatic who looks tired and has a shark fin appearance on the capnogram…
IS HEADED FOR RESPIRATORY ARREST

21. The Head Injured Patient
Carbon dioxide dilates the cerebral blood vessels,
increasing the volume of blood in the intracranial vault and
therefore increasing ICP
Recognizing the head
injured patient and
titrating their CO2
levels to the 30-3530-35
mmHgmmHg range can help
relieve the untoward
effects of ICP

22. Titrate EtCO2
The Head Injured Patient
Titration IS NOT hyperventilation. Intubating a head
injured patient and using capnography gives a means to
closely monitor CO2 levels.
Keep them between 30 and 35 mmHg

23. EtCO2 and Cardiac Arrest
The capnograph of an intubated cardiac arrest
patient is a direct correlation to cardiac output
Increase in CO2 during CPR can
be an early indicator of ROSC

24. Termination of Resuscitation
EtCO2 measurements during a resuscitation give
you an accurate indicator of survivability for
patients under CPR
Non-survivors <10 mmHg10 mmHg
Survivors >30 mmHg30 mmHg
((to discharge)

25. ET Tube Verification
• Verification of proper tube placement
There is simply NO BETTER WAY to confirm proper tube placement
than with waveform capnography…. PERIOD!!!

27. 4 Main Uses of Capnography
Core Concepts
• What is the characteristic shape of a capnogram for a COPD patient?
• Describe how to determine the severity of an asthma attack using
capnography?
• What level should you maintain a severe head injured patient’s CO2 at?
• What are two ways that capnography can assist during CPR?

28. Inadequate Seal
Troubleshooting
As air escapes around the cuff during BVM respirations the waveform
will distort, alerting you to a possibly deflated or damaged ET cuff

29. Obstruction
Troubleshooting
An obstructed ET tube may have an erratic EtCO2 value with a very
irregular waveform

30. Rebreathing
Troubleshooting
A capnogram that does not touch the baseline is indicative of a
patient who is rebreathing CO2 through insufficient inspiratory or
expiratory flow

31. QUIZ

32. Hypoventilation

33. Rebreathing

34. Esophageal Tube

35. Asthma (bronchospasm)

36. Normal

37. Questions?