CAPNOGRAPHY presented by: Fred Halazon, NREMT-P Mike Burke, NREMT-P Cunningham Fire presented by: Fred Halazon, NREMT-P Mike Burke, NREMT-P Cunningham Fire

What is Capnography? Noninvasive, continuous measurement of exhaled carbon dioxide concentration over time Digital display provides EtCO 2 value Provides a distinct waveform for each respiratory cycle Noninvasive, continuous measurement of exhaled carbon dioxide concentration over time Digital display provides EtCO 2 value Provides a distinct waveform for each respiratory cycle

Overview Anatomy & Physiology Capnographic waveform Diagnosing different waveforms Case studies Anatomy & Physiology Capnographic waveform Diagnosing different waveforms Case studies

Relevance Endotracheal tube Verification Cardiac Arrest Ventilation Bronchospastic Disease Early detection of cellular hypoxia Endotracheal tube Verification Cardiac Arrest Ventilation Bronchospastic Disease Early detection of cellular hypoxia

History of Capnography in EMS Colormetric- Useful device to confirm ET tube placement in patients not in cardiac arrest Tube could be in esophagus or that circulation is not bringing CO 2 to the lungs Prone to contamination, leads to false negatives Colormetric- Useful device to confirm ET tube placement in patients not in cardiac arrest Tube could be in esophagus or that circulation is not bringing CO 2 to the lungs Prone to contamination, leads to false negatives

History of Capnography in EMS Pulse oximetry preceded capnography Pulse oximetry measures oxygenation Capnography measures ventilation New technologies now allow use in EMS Pulse oximetry preceded capnography Pulse oximetry measures oxygenation Capnography measures ventilation New technologies now allow use in EMS

Capnometry Provides only a numerical measurement of carbon dioxide ( EtCO 2 )

Capnogram A waveform display of carbon dioxide over time

Definition of Capnography Numerical value of the EtCO 2 AND Waveform of the concentration present in the airway Respiratory rate detected from the actual airflow Numerical value of the EtCO 2 AND Waveform of the concentration present in the airway Respiratory rate detected from the actual airflow

Oxygen> lungs> alveoli> blood Muscles + organs Oxygen + Glucose O2O2 CO 2 O2O2 cellsenergy blood lungs breath

Capnographic Waveform ExpirationInspiration

Physiology of CO 2 Concentration of CO 2 in alveoli: Varies INDIRECTLY with ventilation Increase Ventilation:Decrease CO 2 in Alveoli Decrease Ventilation:Increase CO 2 in Alveoli Varies DIRECTLY with perfusion Decrease Perfusion:Decrease CO 2 in Alveoli Increase Perfusion: Increase CO 2 in Alveoli Concentration of CO 2 in alveoli: Varies INDIRECTLY with ventilation Increase Ventilation:Decrease CO 2 in Alveoli Decrease Ventilation:Increase CO 2 in Alveoli Varies DIRECTLY with perfusion Decrease Perfusion:Decrease CO 2 in Alveoli Increase Perfusion: Increase CO 2 in Alveoli

Oxygenation and Ventilation What is the difference? Oxygenation: is the transport of O 2 via the bloodstream to the cells Oxygen is required for metabolism Ventilation: is the movement of air into and out of the lungs exhaling of CO 2 via the respiratory tract Carbon dioxide is a byproduct of metabolism Oxygenation: is the transport of O 2 via the bloodstream to the cells Oxygen is required for metabolism Ventilation: is the movement of air into and out of the lungs exhaling of CO 2 via the respiratory tract Carbon dioxide is a byproduct of metabolism

Oxygenation Measured by pulse oximetry (SpO 2 ) Noninvasive measurement Percentage of oxygen in red blood cells Changes in ventilation take several minutes to be detected Affected by motion artifact, poor perfusion, temperature Measured by pulse oximetry (SpO 2 ) Noninvasive measurement Percentage of oxygen in red blood cells Changes in ventilation take several minutes to be detected Affected by motion artifact, poor perfusion, temperature

Ventilation Measured by the end-tidal CO 2 Partial pressure (mm Hg) or volume (%) of CO 2 in the airway at end of exhalation Breath-to-breath measurement provides information within seconds Not affected by motion artifact, distal circulation, temperature Will see respiratory arrest immediately Measured by the end-tidal CO 2 Partial pressure (mm Hg) or volume (%) of CO 2 in the airway at end of exhalation Breath-to-breath measurement provides information within seconds Not affected by motion artifact, distal circulation, temperature Will see respiratory arrest immediately

Distinguishing between oxygenation and ventilation

If ventilation is held constant, then changes in EtCO 2 are due to changes in cardiac output

Cardiac Output (L) EtCO2 (mm Hg)

Value of the Capnographic Waveform Provides valid EtCO 2 value Visual assessment of patient airway integrity Verify proper ET tube placement (with pulmonary perfusion) Waveforms have characteristic shape like an ECG Provides valid EtCO 2 value Visual assessment of patient airway integrity Verify proper ET tube placement (with pulmonary perfusion) Waveforms have characteristic shape like an ECG

Capnographic Waveform Height shows amount of CO 2 Length depicts time Height shows amount of CO 2 Length depicts time

End-tidal CO 2 (EtCO 2 ) Allows monitoring for changes in Ventilation—Asthma, COPD, airway edema, FBAO, stroke, overdose Diffusion—Pulmonary edema, alveolar damage, Pneumonia Perfusion—shock, pulmonary embolus, cardiac arrest, severe dysrhythmias Red Blood Cell Function: CO poisoning (COHb), hydrogen cyanide, severe anemia Allows monitoring for changes in Ventilation—Asthma, COPD, airway edema, FBAO, stroke, overdose Diffusion—Pulmonary edema, alveolar damage, Pneumonia Perfusion—shock, pulmonary embolus, cardiac arrest, severe dysrhythmias Red Blood Cell Function: CO poisoning (COHb), hydrogen cyanide, severe anemia

Decreased EtCO 2 Decreased Metabolism Analgesia/ sedation Hypothermia Circulatory System Cardiac arrest Embolism Sudden hypovolemia or hypotension Decreased Metabolism Analgesia/ sedation Hypothermia Circulatory System Cardiac arrest Embolism Sudden hypovolemia or hypotension Respiratory System Alveolar hyperventilation Bronchospasm Mucus plugging Equipment Leak in system Partial obstruction ETT in hypopharynx

Increased EtCO 2 Increased Metabolism Pain Hyperthermia Malignant hyperthermia Shivering Circulatory System Increased cardiac output with constant ventilation Increased Metabolism Pain Hyperthermia Malignant hyperthermia Shivering Circulatory System Increased cardiac output with constant ventilation Respiratory System Respiratory insufficiency Respiratory depression Obstructive lung disease Equipment Defective exhalation valve Exhausted CO 2 absorber

End tidal of 0 Respiratory failure Cardiac arrest Airway displacement Airway obstruction Disconnection of ventilation system Respiratory failure Cardiac arrest Airway displacement Airway obstruction Disconnection of ventilation system

Major Benefits in Pre-Hospital Verifying ETT placement and continuous monitoring of position during transport Cardiac Arrest Effectiveness of cardiac compression Predictor of survival Sign of return of cardiac function Ventilation Bronchospastic Disease Verifying ETT placement and continuous monitoring of position during transport Cardiac Arrest Effectiveness of cardiac compression Predictor of survival Sign of return of cardiac function Ventilation Bronchospastic Disease

ETT Displacement Most likely occurs when patient is moved

Dislodged

Right Main Bronchi/Pneumothorax

CPR Force, depth, and rate of chest compressions 100% mortality if unable to achieve an EtCO2 of 10 mm Hg after 20 minutes

CPR

ROSC

End Tidal with Return of circulation

Hyperventilation Hypocapnia < 35 mmHg Normal range is mm Hg (5% vol) How would hyperventilation change the waveform? (26-30) Frequency Duration Height Shape Hypocapnia < 35 mmHg Normal range is mm Hg (5% vol) How would hyperventilation change the waveform? (26-30) Frequency Duration Height Shape

Hyperventilation 45 0

Hypoventilation Hypercapnia > 45 mmHg How would hypoventilation change the waveform? (4-12) Frequency Duration Height Shape Hypercapnia > 45 mmHg How would hypoventilation change the waveform? (4-12) Frequency Duration Height Shape

Hypoventilation 45 0

Bronchospasm Alveoli unevenly ventilated on inspiration Prolonged expiratory time Air trapping “Shark Fin” shaped waveform What about COPD? Alveoli unevenly ventilated on inspiration Prolonged expiratory time Air trapping “Shark Fin” shaped waveform What about COPD?

Bronchospasm 45 0

COPD

Asthma Initial After therapy

What is Wrong?

Documentation Continuous waveform allows for legal documentation Proof of correct tube placement, RR, EtCO 2 Effectiveness of treatment in patient care, early detection of deterioration Continuous waveform allows for legal documentation Proof of correct tube placement, RR, EtCO 2 Effectiveness of treatment in patient care, early detection of deterioration

The era is over when we can justify not knowing whether an ETT is in place or not. We may not be able to intubate everybody, but we must always know when the tube is in place or not. The era is over when we can justify not knowing whether an ETT is in place or not. We may not be able to intubate everybody, but we must always know when the tube is in place or not.

Who get’s End tidal All pt’s with an ETT tube or King airway All unconscious or altered pt’s Any pt with BVM ventilation Respiratory distress pt’s All pt’s with an ETT tube or King airway All unconscious or altered pt’s Any pt with BVM ventilation Respiratory distress pt’s

Bottom line Treat the patient in front of you

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