2. At the end of this session students will be
able to:
1. Define Capnography
2. State the indications for Capnography
3. Identify the phases of Capnography.
4. State the contraindications for
Capnography.
2
3. Capnography is the measurement, display,
and monitoring of the concentration or partial
pressure of CO₂ (PETCO₂) in the respiratory
gases at the end of expiration.
3
4. The capnogram displays the maximum
inspiratory and expiratory CO₂ concentrations
during a respiratory cycle, which indirectly
reflect the production of CO₂ by the tissues
and the transport of CO₂ to the lungs.
4
5. Sudden changes in CO₂ elimination should be
monitored in selected cardiorespiratory
patients and postoperatively after major
cardiothoracic surgeries.
5
6. Capnography can also be used to verify ETT
position and monitor the effectiveness of
CPR.
6
7. A monitoring device that measures the
concentration of carbon dioxide in exhaled
air and displays a numerical readout and
waveform tracing (Merriam Webster
dictionary).
7
8. The graphical measurement of carbon dioxide
partial pressure (mm Hg) during expiration is
referred to has End-tidal capnography .
First established in the 1930s,
8
9. Clinical use of end-tidal carbon dioxide
measurement became accessible in the 1950s
with the production and distribution of
capnograph monitors.
9
10. With continuous technological advancements,
end-tidal carbon dioxide monitoring has
become a key component in the advancement
of patient safety within anesthesiology.
10
11. The American Society of Anesthesiologists
(ASA) endorses end-tidal capnography as a
standard of care for general anesthesia,
moderate sedation, and deep sedation.
11
12. Specialties, including critical care and
emergency medicine, are more frequently
implementing end-tidal capnography
monitoring.
12
13. General anesthesia
Monitored anesthesia care
Procedural sedation and analgesia
Cardiac arrest (confirm tracheal intubation)
Cardiopulmonary arrest (determine adequate
chest compression)
Analysis of ventilation
13
14. Cellular metabolism produces carbon dioxide,
The balance between production and
elimination can be followed in the rise and
fall of end-tidal carbon dioxide as measured
by capnography.
14
15. End-tidal carbon dioxide waveforms provide
clinicians with a tool for quick and reliable
diagnoses of pulmonary pathophysiology.
End-tidal carbon dioxide is displayed as a
waveform with partial pressure of carbon
dioxide on the Y-axis and time on the X-axis.
15
17. Phase I of the capnogram represents baseline
inspired gas (normally devoid of carbon
dioxide).
Phase II represents expired air with an
upward sloping curve This phase displays the
transition from dead space air flow to alveolar
air flow.
17
18. Phase III, the plateau, represents the partial
pressure of carbon dioxide exchanged at the
alveoli. This plateau number represents end-
tidal carbon dioxide.
18
19. Phase IV, downward deflection, represents
the inspiratory point in the ventilatory cycle.
This phase displays the transition from
alveolar air flow to fresh air inflow, or
“scrubbed” air in a closed circuit.
19
21. The information captured by end-tidal
capnography (partial pressure of carbon dioxide)
is devoid of volumetric information. Therefore,
capnography should be used with end-tidal
volume measurements to fully assess ventilation
parameters.
21
22. Continuous end-tidal carbon dioxide
monitoring can be an early warning sign to
hypoxia. Several studies demonstrate that
respiratory depression is detected via end-
tidal capnography 30-60 seconds prior to
detection via oxygen saturation (SpO2).
22
23. Long periods of a flat wave form indicate:
◦ apnea
◦ dislodged endotracheal tube
◦ esophageal intubation
◦ patient disconnected from ventilator
23
24. There are no absolute contraindications to
capnography in mechanically ventilated
patients provided that the data obtained are
evaluated with consideration given to the
patient’s clinical condition.
24
25. Jones, J & Fix, B. (2009). Critical Care Notes:
Clinical Pocket Guide. Philadelphia.
MCG Health, Inc. Respiratory Care Services:
ETCO2/Capnography/Capnometry . Retreived
from https://paws.augusta.edu/pub/respira-
tory/Documents/adult_protocol/ETCO2policy
pdf
Merriam Webster dictionary. (1828). Retreived
from https://www.merriam
webster.com/dictionary/capnograph
25
26. Press, D, C. Desai, M, A. Tanaka, P,P. Macario,
A. (2015). End-Tidal Capnography.
Retreived from
https://emedicine.medscape.com/article/
2116444- overview#a5
26
