used by anesthesiologists since the 1970s standard of care in the or since 1991 new...
TRANSCRIPT
CAPNOGRAPHY
UNION HOSPITAL EMERGENCY DEPARTMENT
KELLY MILLS RN CEN
History of capnography
Used by anesthesiologists since the 1970s
Standard of care in the OR since 1991 New recommendations and JCAHO
standards now expanding utilization in other areas specifically for procedural sedation.
Indications for Use -End-Tidal CO2 Monitoring
Validation of proper endotracheal tube placement
Detection and Monitoring of Respiratory depression
Hypoventilation Obstructive sleep apnea Procedural sedation Adjustment of parameter settings in
mechanically ventilated patients
Definition of Capnography
A numerical value of the EtCO2 AND A waveform of the concentration of CO2 present in the airway
Respiratory rate detected from the actual airflow
Capnometer
A Capnometer provides only a numerical measurement of carbon dioxide.
Capnogram
A Capnogram is a waveform display of carbon dioxide over time
Oxygenation and Ventilation
What is the difference?
Oxygenation
Measured by pulse oximetry (SpO2)
Noninvasive measurement Percentage of oxygen in red blood
cells Changes in ventilation take
minutes to be detected Affected by motion artifact, poor
perfusion, etc.
Ventilation
Measured by the end-tidal CO2 Partial pressure (mm Hg) or
volume(% vol) 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, etc.
Oxygenation and Ventilation Respiratory Cycle
= separate physiologic processes:
Oxygenation Ventilation
Comparing Capnography with Pulse Oximetry Capnography Carbon dioxide Reflects ventilation Hypoventilation /
apnea detected immediately
Reflects change in ventilation within 10 seconds
Should be used with pulse oximetry
Pulse oximetry Oxygen saturation Reflects oxygenation SpO2 changes lag
when patient is hypoventilating or apneic
Reflects change in oxygenation within 5 minutes
Should be used with capnography
Respiration–The BIG Picture
Physiological Factors Affecting ETCO2 Levels
Normal Arterial & ETCO2 Values
Physiology
Relationship between CO2 and RR
› RR CO2 Hyperventilation
› RR CO2 Hypoventilation
There is an inverse relationship between your respiratory rate and your CO2 level.
As you breath faster your RR goes up, your body is unable to hold onto CO2 and therefore blows it off faster so those levels go down.
As you breath more slowly, your RR goes down, your body is holding more CO2 due to the lack of breaths taken and the CO2 level goes up.
Elements of a Waveform
Alveolar gas mixes with dead space
Alveolar Gas
End of exhalation
Inspiration
The Normal CO2 Waveform
A – B BaselineB – C Expiratory UpstrokeC – D Expiratory PlateauD ETCO2 valueD – E Inspiration begins
ETT
•A normal capnogram is the best evidence that the ETT is correctly positioned•With an esophageal tube little or no CO2
is present
Hypoventilation(increase in ETCO2)
Possible causes:Decrease in respiratory rateDecrease in tidal volumeIncrease in metabolic rateRapid rise in body temperature
(hypothermia)
Waveform: Regular Shape, Plateau Above Normal
• Indicates increase in ETCO2 Hypoventilation Respiratory depressant drugs Increased metabolism
Fever, pain, shivering• Interventions
Adjust ventilation rate Decrease respiratory depressant drug dosages Assess pain management Conserve body heat
Hyperventilation(decrease in ETCO2)
Possible causes:Increase in respiratory rateIncrease in tidal volumeDecrease in metabolic rateFall in body temperature (hyperthermia)
Waveform: Regular Shape, Plateau Below Normal
• Indicates CO2 deficiency Hyperventilation Decreased pulmonary perfusion Hypothermia Decreased metabolism
• Interventions Adjust ventilation rate Evaluate for adequate sedation Evaluate anxiety Conserve body heat
Obstruction-Shark Fin
Possible causes:Partially kinked or occluded artificial
airwayPresence of foreign body in the airwayObstruction in expiratory limb of the
breathing circuitBronchospasm-Can indicate need for
bronchodilators.
Sudden Loss of Waveform
ApneaAirway ObstructionDislodged airway (esophageal)Airway disconnectionVentilator malfunctionCardiac Arrest
Curare Cleft
Curare cleft is when a neuromuscular blockade wears off
The patient takes small breaths that causes the cleft
Management: consider neuromuscular blockade
re-administration
TroubleshootingSudden increase in EtCO2
Malignant HyperthermiaVentilation of previously unventilated lungIncrease of blood pressureRelease of tourniquetBicarb causes a temporary <2 minute rise in ETCO2
TroubleshootingEtCO2 values drop to 0
Extubation/Movement into hypopharynxVentilator disconnection or failureEtCO2 defectETT kink
TroubleshootingSudden decrease EtCO2 (not to 0)
Leak or obstruction in systemPartial disconnectPartial airway obstruction (secretions)High-dose epi can cause a decrease
TroubleshootingContinual, exponential decrease in EtCO2
Pulmonary EmbolismCardiac ArrestSudden hypotension/hypovolemiaSevere hyperventilation
What does it really do for me?
Non-Intubated Applications
›Bronchospasms: asthma, COPD, anaphlyaxis›Hypoventilation: drugs, stroke, CHF, post-Ictal›Shock and circulatory compromise›Hyperventilation Syndrome: biofeedback
Intubated Applications›Verification of ETT placement›ETT surveillance during transport›Control ventilations during CHI and increased ICP›CPR: compression efficacy, early signs of ROSC, survival predictor
MICROSTREAM CAPNOGRAPHY SOLUTIONS
MICROSTREAM CAPNOGRAPHY SOLUTIONS
Small pin holes deliver pillow of oxygen around both nose and mouth Nasal and Oral Sampling
CO2 sampling / O2 delivery for non-intubated patients
Uni-junction™ of sampling ports prevents dilution from nonbreathing source
Increased surface area provides greater sampling accuracy in the presence of low tidal volume
Smart CapnoLine™ Plus O2nasal cannula for CO2 measurement and O2 delivery
O2 delivery method reduces CO2 sampling dilution
–Solution for high flow O2 delivery (works effectively under oxygen delivery mask)
FilterLine® patient interfacesPrevents moisture from entering monitor
Replaces water trap
Capnography in procedural sedation
Accurately monitors RR Monitors adequate ventilation with non-intubated
patients Monitors potential risk of over-sedation resulting in Hypoventilation more effectively than pulse
oximetry Early indicator of airway obstruction Early warning of apnea Adds an additional level of patient safety providing
the caregiver with vital information to make accurate assessments and timely interventions for the patient