UNION HOSPITAL EMERGENCY DEPARTMENT KELLY MILLS RN CEN 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 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 End of exhalation Alveolar Gas Alveolar gas mixes with dead space Inspiration

The Normal CO2 Waveform A – B Baseline B – C Expiratory Upstroke C – D Expiratory Plateau D ETCO2 value D – 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 rate Decrease in tidal volume Increase in metabolic rate Rapid 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 rate Increase in tidal volume Decrease in metabolic rate Fall 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 airway Presence of foreign body in the airway Obstruction in expiratory limb of the breathing circuit Bronchospasm-Can indicate need for bronchodilators.

Sudden Loss of Waveform Apnea Airway Obstruction Dislodged airway (esophageal) Airway disconnection Ventilator malfunction Cardiac 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

Troubleshooting Sudden increase in EtCO2 Malignant Hyperthermia Ventilation of previously unventilated lung Increase of blood pressure Release of tourniquet Bicarb causes a temporary <2 minute rise in ETCO2

Troubleshooting EtCO2 values drop to 0 Extubation/Movement into hypopharynx Ventilator disconnection or failure EtCO2 defect ETT kink

Troubleshooting Sudden decrease EtCO2 (not to 0) Leak or obstruction in system Partial disconnect Partial airway obstruction (secretions) High-dose epi can cause a decrease

Troubleshooting Continual, exponential decrease in EtCO2 Pulmonary Embolism Cardiac Arrest Sudden hypotension/hypovolemia Severe 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 O2 nasal 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 interfaces Prevents 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