Presented by:Presented by:Christopher Smith FF/NREMT-PChristopher Smith FF/NREMT-P
Understand the difference between oxygenation and ventilation
Define end-tidal CO2
Understand the difference between waveform and colorimetric monitoring
State what the normal range of EtCO2 is Identify the phases of a normal waveform Recognize normal and abnormal
waveforms of capnography
ETCO2 is the monitoring of the concentration or partial pressure of carbon dioxide (CO2) in the respiratory gases.
EtCO2 assesses ventilation, by measuring carbon dioxide in the exhaled gas
What is the difference?
Two completely separate functions of life
Oxygenation is the transport of O2 from the bloodstream to the body’s cells Oxygen is required for metabolism
Ventilation is the exhaling of CO2 through the respiratory system Carbon dioxide is a byproduct
of metabolism
OxygenationOxygenation(Pulse-Ox(Pulse-Ox))
CellularCellularMetabolismMetabolism
VentilationVentilation(ETCO2)(ETCO2)
COCO22
OO22
Measured by pulse oximetry (SpO2) Definition - Percentage of oxygen in red blood
cells Non-invasive monitoring Changes in ventilation take several minutes
to be detected Affected by motion artifact, poor perfusion
Measured by the end-tidal CO2
Definition - Partial pressure (mmHg) or volume of CO2 in the airway at the end of exhalation
Breath-to-breath measurement provides information within seconds
Not affected by motion artifact, poor perfusion
Oxygenation Oxygen for
metabolism SpO2 measures
% of O2 in red blood cells
SPO2 reflects change in oxygenation within up to5 minutes
Ventilation Carbon dioxide
from metabolism EtCO2 measures
exhaled CO2
ETCO2 reflects change in ventilation within 10 seconds
Why measure ETCO2?
Pulse oximetry – Over 3-5min to see the decrease in O2 – External and some internal factors
affect the reading Capnography – Breath to Breath – Not affected by external factors
“Gold standard” for verification of ET tube placement
Immediately detect changes in ET tube position
Earliest indication of ROSC Verification of ETT placement Recognition of specific medical conditions Guide treatment decisions CPR: adequate compressions and possible
survival indicator
Bronchospasm Asthma COPD Burns, Anaphylaxis, Trauma Hypoventilation Drugs, stroke, CHF, post-ictal Shock Hyperventilation syndrome
Colorimetric Sensors/Detectors Easy Cap Device is attached to the ET
Tube. Fairly accurate (not for long term use) Litmus paper is worthless when wet Disposable
A qualitative recording of the pt’s ETCO2 reading by use of an illustrated waveform and quantitative numerical value.
Interpreting EtCO2 Measuring Physiology
Capnography waveform
Normal waveform of one respiratory cycle Height shows amount of CO2
Length equals time of exhalation
Phase I: Respiratory Baseline Phase II: Expiratory Upstroke Phase III: Expiratory Plateau ETCO2: Peak EtCO2 level Phase IV: Inspiratory Downstroke
Normal range is 35-45mm Hg
Normal WaveformNormal Waveform
45
0
45
0
HypoventilationHypoventilation
NormalNormal
45
0
45
0
BronchospasmBronchospasm
HyperventilationHyperventilation
45
0
Decreased ETCO2 is pattern for hyperventillationAnxietyRespiratory Alkalosis
Increased ETCO2 is pattern for Hypoventillation(air trapping)COPDRespiratory Acidosis
“Shark Fin” shape to waveform
45
0
45
0
Normal
Bronchospasm
Oxygenation and ventilation Pulse oximetry
Measures O2 saturation in blood Slow to indicate change in ventilation
Capnography Measures CO2 in the the airway Provides a breath-to-breath
status of ventilation
ETCO2 is measured through expired ventillation End-tidal CO2
Normal EtCO2 range is 35-45mmHg Several conditions can be immediately
detected with capnography