TITLE
End Tidal Carbon Dioxide (EtCO2) Monitoring
Last Revised/Reviewed
Effective Date:
NUMBER
TJC FUNCTIONS
PC
APPLIES TO
PW
I.
July, 2012
SCOPE / PURPOSE / POLICY STATEMENT
Capnography is a tool for non-invasively measuring the partial pressure of carbon
dioxide at the end of exhalation and directly measures ventilatory performance of the
lungs. Carbon dioxide, produced during aerobic metabolism, builds up in the tissues. It
diffuses out of the cells, into the circulation and across the alveolar membrane during
respiration. It is then excreted by exhalation. Poor ventilation, as a result of sedation,
results in a build-up of CO2, which is recognized by the sensor. A decrease in oxygen
saturation, as reflected in a drop in the SpO2 displayed by the monitor, is a late indicator
of hypoventilation and apnea. EtCO2 monitoring, through capnography, gives an
accurate picture of the patient’s ventilatory status.
II.
QUALIFIED PERSONNEL
A. Physicians/Licensed Independent Practioner
B. Registered Nurses (RN) following successful completion of the
appropriate competency checklists.
C. Respiratory Therapist
STANDARD OF CARE
Patients who are at risk for respiratory depression or meet the suggested
recommendations for EtCO2 monitoring may benefit from the use of this
monitoring.
III.
DEFINITIONS
End Tidal Carbon Dioxide (EtCO2) – Peak concentration of carbon
dioxide occurring at the end of expiration. Normal EtCO2 value: 30 – 45
mmHg.
Capnogram: A graphical waveform display of carbon dioxide
concentration over time.
Capnometry: Continuous and non-invasive measurement and graphical
display of EtCO2. There is a sample chamber/sensor placed for optimum
evaluation of ventilation with a numeric display of carbon dioxide.
Pulse Oximetry: The amount of oxygen on the hemoglobin molecule
reflecting oxygenation. Normal value 93-100%.
IV.
EQUIPMENT
1. Personal protective equipment, including face shield, mask, and gloves
2. Capnograph
3. Airway adapter EtCO2:
For intubated patient with non-humidified ventilation, you can use a Microstream
FilterLine set. For humidified ventilation, use a FilterLine H Set.
For non-intubated patients, the gas sample is taken through a Nasal FilterLine, or
a Smart CapnoLine (which is a combined oral-nasal FilterLine). In parallel to the
measurement of the CO2, oxygen (O2) may be delivered to the patient to support
gas exchange. This is done by using an O2/CO2 FilterLine, or a Smart CapnoLine
O2 (a combined oral-nasal O2/CO2 FilterLine).
IV.
PROCEDURE
The procedure serves as guidelines to assist personnel in accomplishing the goals of the
procedure. While following these procedural guidelines, personnel are expected to exercise
judgment within their scope of practice and/or job responsibilities.
Set-up
1. Obtain order for continuous end tidal carbon dioxide monitoring with
capnography.
2. Verify correct patient with two identifiers.
3. If the patient is alert, explain the procedure to the patient; if the patient is not
alert, explain the procedure to the family.
4. Ensure the patient understands pre-procedural teachings. Answer questions as
they arise and reinforce information as needed.
5. Assess for proper functioning of capnograph, including electronic equipment,
self-start, autocalibration, airway adaptor, sensor, and display monitor.
6. Connect capnograph into grounded wall outlet; connect appropriate patient
cable into display monitor; turn on instrument.
7. Perform calibration routine. Calibration procedure should occur daily or more
often when instrument is in clinical use.
8. If patient is not intubated, apply EtCO2 nasal cannula and connect to
capnograph.
9. Assemble airway adaptor, sensor, and display monitor; connect to the patient’s
circuit as close as possible to the patent’s ventilation connection.
10. Ensure that the light source is on top of the circuit so that condensation and
secretions do not pool and obstruct the light transmission in mainstream sensor.
11. Set appropriate alarms. Alarm limits should include respiratory rate, apnea,
default, high and low EtCO2 and minimal levels of inspiratory CO2.
Patient Monitoring and Care
1. Observe artificial airway for patency.
2. If the patient is not intubated, check nasal cannula or mouthpiece for proper
placement and ensure that it is clear of secretions.
3. Observe waveform for quality and EtCO2 value.
a. Observe waveform for gradually increasing EtCO2.
b. Observe for a gradual increase in both baseline CO2 and EtCO2
c. Observe for an exponential fall in EtCO2
d. Observe for decreased EtCO2 (with normal waveform)
e. Observe for a sudden decrease in EtCO2 to low values
f. Observe for a sudden decrease in EtCO2 to near zero.
g. Observe for a sustained low EtCO2 without alveolar plateau.
4. Routinely monitor the airway adaptor or sampling port for signs of obstruction
5. Evaluate the patient’s response to activities that may positively or negatively
affect ventilation.
Using the FilterLine and Airway Adapter
1. Attach the female Luer connector to the CO2 inlet connector on the extension
by pushing the socket cover down and screwing the connector into place.
2. Check that the FilterLine is not kinked.
3. Change the FilterLine if a “CO2 OCCLUSION” INOP appears on the monitor
or if the readings become extremely erratic.
4. Disconnect the FilterLine during suctioning and nebulizing therapies.
5. Check the table in the Microstream CO2 Accessories section of the Accessories
chapter for typical usage times for the different Microstream accessories.
6. CO2 values for non-intubated patients using Microstream accessories will
always tend to be lower than for intubated patients. If values appear extremely
low, check whether the patient is breathing through the mouth or whether one
nostril is blocked
Removing Exhaust Gases from the System
WARNING Anesthetics: When using the Microstream CO2 measurement on
patients who are receiving or have recently received anesthetics, connect the
outlet to a scavenging system, or to the anesthesia machine/ ventilator, to avoid
exposing medical staff to anesthetics.
Use an exhaust tube to remove the sample gas to a scavenging system. Attach it to
the MMS Extension at the outlet connector.
Suppressing Zero Calibration
To prevent an automatic zero calibration from being started in the next five
minutes,
 In the setup CO2 menu, select “No Zero for 5 Min”, or select the
“Suppress CO2” Zero SmartKey, if configured.
Selecting “No Zero” for 5 Min or selecting the “Suppress CO2 Zero SmartKey”
again before the timer has timed out resets the timer to five minutes, unless an
Auto Zero became due during the previous suppression.
Adjusting the CO2 Wave Scale
1. In the CO2 wave menu or the setup CO2 menu, select “Scale”.
2. Choose a suitable scale range from the pop-up list.
Setting up CO2 Corrections
Temperature, water vapor in the patient’s breath, barometric pressure, and the
proportions of O2, N2O and Helium in the mixture all influence CO2 absorption. If
values seem inaccurately high or low, check that the monitor is using the
appropriate corrections.
Correction
Altitude (M3014A
only)
O2 (M3014A only)
Altitude is set during installation. The monitor automatically
applies an appropriate correction.
In the setup CO2 menu, select Oxygen Corr and select a value
between 0% and 100%, the default value is 16% (expired O2). If
you are not measuring the expired O2, estimate it by subtracting
5% from the inspired O2.
At installation, the monitor is configured to automatically apply
either Body Temperature Pressure Saturated (BTPS) or Standard
Humidity
Temperature Pressure Dry (STPD). To see which, go to the setup
CO2 menu, and scroll down to look at HumidtyCorr.
In the Setup CO2 menu, select N2O Corr and turn on or off. If
N2O (M3016A
N2O is present in the ventilation gas mixture, you must turn this
mainstream and
on.
M3015A microstream If the N2O correction is not available in the setup CO2 menu, the
only)
CO2 measurement in your MMS Extension does not require N2O
correction or it is setup with Gas Corr (see below).
In the setup CO2 menu, select Gas Corr and select helium, N2O or
turn off. If helium or N2O is present in the ventilation gas mixture,
you must make the appropriate selection.
Gas (M3014A only) If the gas correction is not available in the setup CO2 menu, the
CO2 measurement in your MMS Extension does not require N2O
or helium correction or the N2O correction is setup with N2O Corr
(see above).
Correction
In the setup CO2 menu, select Agent Corr and select the
concentration of the anesthetic agent (between 0.0% and 20.0%).
Agent (M3014A only)
If an anesthetic agent is present in the ventilation gas mixture, you
must select the appropriate concentration.
Altitude (M3014A
Altitude is set during installation. The monitor automatically
only)
applies an appropriate correction.
In the Setup CO2 menu, select Oxy. Corr. and select a value
between 0% and 100%, the default value is 16% (expired O2). If
O2 (M3014A only)
you are not measuring the expired O2, estimate it by subtracting
5% from the inspired O2.
At installation, the monitor is configured to automatically apply
either Body Temperature Pressure Saturated (BTPS) or Standard
Humidity
Temperature Pressure Dry (STPD). To see which, go to the Setup
CO2 menu, and scroll down to look at HUM Corr..
In the Setup CO2 menu, select N2O Corr. and turn on or off. If
N2O is present in the ventilation gas mixture, you must turn this
N2O (M3016A
on.
mainstream and
M3015A microstream If the N2O correction is not available in the setup CO2 menu, the
only)
CO2 measurement in your MMS Extension does not require N2O
correction or it is setup with Gas Corr. (see below).
In the Setup CO2 menu, select Gas Corr. and select Helium, N2O
or turn off. If helium or N2O is present in the ventilation gas
Gas (M3014A only) mixture, you must make the appropriate selection.
If the Gas correction is not available in the setup CO2 menu, the
CO2 measurement in your MMS Extension does not require N2O
or helium correction or the N2O correction is setup with N2O
Corr. (see above).
In the Setup CO2 menu, select Agt. Corr. and select the
concentration of the anesthetic agent (between 0.0% and 20.0%).
Agent (M3014A only)
If an anesthetic agent is present in the ventilation gas mixture, you
must select the appropriate concentration.
Suppressing Sampling (not Mainstream CO2)
To temporarily stop sampling,
 In the setup CO2 menu, select Pump 15 min off or use the CO2 Pump Off
SmartKey if available.
Selecting Pump 15 min off again before fifteen minutes have passed resets the
timer to fifteen minutes.
To re-start the pump
 In the setup CO2 menu, select Pump On.
Changing the Apnea Alarm Delay
This determines the time limit after which the monitor alarms if the patient stops
breathing.
1. In the Setup CO2 menu, select awRR.
2. In Setup awRR menu, select Apnea Time.
3. Choose the apnea alarm delay time.
WARNING
Safety and effectiveness of the respiration measurement method in the detection
of apnea, particularly the apnea of prematurity and apnea of infancy, has not been
established.
Prolonged delay: The selected apnea alarm delay may be prolonged by up to 17
seconds, if an apnea occurs during the automatic zero process. This applies to the
Microstream (M3015A) measurement only.
Deriving Alarms From awRR
1. In the Setup CO2 menu, select awRR.
2. In the Setup awRR menu, select Alarms.
3. Choose On to derive alarms from the airway respiration signal or Off to
disable them.
Changing awRR Alarm Limits
1. In the Setup CO2 menu, select awRR.
2. Select High Limit to set the upper alarm limit.
Select Low Limit to set the lower alarm limit.
3. Select the appropriate setting.
V.
DOCUMENTATION
Documentation should include the following:
 Patient and family education
 Mechanical ventilator settings
 Petco2 value and capnogram
 Arterial blood gas values if ordered
 Times of calibration
 Respiratory therapies
 Medications that may affect respiratory system (e.g. neuromuscular
blockers, sedatives, or bronchodilators)
 Unexpected outcomes
 Nursing interventions
VI.
SUBMITTED BY
Lauren Walker RN, BSN, CCRN
Julia Burgess RN, MS, CCRN, CCNS
VII.
KEYWORDS
End-tidal, CO2, Nasal Cannula, Ventilation End tidal carbon dioxide, respiratory
VIII.
EFFECTIVE DATE
July, 2012