Don t let your patients turn blue! Isn t it about time you used etco 2? American Association of Critical Care Nurses National Teaching Institute Expo Ed 2013 Susan Thibeault MS, CRNA, APRN, CCRN, EMT-P Overview What is capnography and how does it work? The Science Oxygenation Monitoring of ventilation Monitoring of perfusion Monitoring of metabolism 1
The Waveforms Normal Abnormal Overview Use of capnography in clinical practice Overview The Monitors 2
Overview Use of capnography in clinical practice What is Capnography? Capnography is the non-invasive, continuous measurement of CO 2 concentration at the airway; determines the adequacy of ventilation Provides: Respiratory rate detected from the actual airflow Numeric end tidal carbon dioxide (etco 2 ) Normal text book range 35-45 mmhg Waveform representing CO 2 concentration in every breath 3
About oxygenation & ventilation The process of getting O 2 into the body Oxygenation 2-separate physiologic processes Ventilation The process of eliminating CO 2 from the body important but different measurements! http://www.covidien.com Capnography etco 2 Reflects ventilation Hypoventilation & apnea detected immediately Pulse oximetry SpO 2 Reflects oxygenation Values lag with hypoventilation & apnea Cases of respiratory depression were 28 times as likely to be detected, if they were monitored by capnography, as those who were not monitored. end tidal carbon dioxide monitoring is an important addition to oximetry for detecting respiratory depression Waugh et al, Respiratory Care November 2007 Vol 52 No 11 4
Capnography Assesses Physiological Functions METABOLISM PERFUSION ALL THREE ARE IMPORTANT! VENTILATION etco 2 v PaCO 2 End-tidal PCO2 is the partial pressure of CO2 at the end of expiration during tidal breathing. ASSUMED to be representative of alveolar gas etco 2 is lower than 'ideal' alveolar PCO2, because the almost CO2-free gas from alveolar dead space dilutes and lower the end-tidal PCO2. 5
etco 2 v PaCO 2 In a healthy person breathing room air, the difference between arterial PaCO2 and end-tidal PCO2 is small. End-tidal PCO2 is about 2~5mmHg lower The size of this difference is a simple index of the amount of alveolar dead space. Old vs New 2005: Exhaled CO 2 detector 2010: Waveform Capnography 6
Why waveform capnography? Waveform Capnography Most reliable method of confirming and monitoring placement of endotracheal tube Studies of colorimetric and nonwaveform etco 2 accuracy does not exceed that of auscultation and direct visualization for confirming position of endotracheal tube Why waveform capnography? Waveform Capnography Providers should observe a persistent capnographic waveform with ventilation to confirm and monitor endotracheal tube placement... to reduce the risk of unrecognized tube misplacement or displacement 7
Why waveform capnography? Standard physical examination methods, such as auscultation of lungs and epigastrium, visualization of chest movement, and fogging in the tube, are not sufficiently reliable to exclude esophageal intubation in all situations. Source: Verification of Endotracheal Tube Placement - Approved by the ACEP Board of Directors October 2001 http://www.acep.org/1,4923,0.html (policy statement) 15 About the normal waveform Normal textbook etco 2 value: 35-45 mmhg A-B: Baseline, no CO 2 being exhaled 8
About the normal waveform Normal textbook etco 2 value: 35-45 mmhg B-C: Rapid rise in CO 2, early exhalation clearing dead space About the normal waveform Normal textbook etco 2 value: 35-45 mmhg C-D: Alveolar Plateau: Alveolar gas exchange 9
About the normal waveform Normal textbook etco 2 value: 35-45 mmhg D: End of Exhalation: Point where etco 2 is measured About the normal waveform Normal textbook etco 2 value: 35-45 mmhg D-E: Inspiration, rapid decrease of CO 2 10
Review of the normal waveform Normal textbook etco 2 value: 35-45 mmhg A-B: Baseline, no CO 2 being exhaled B-C: Rapid rise in CO 2, early exhalation clearing dead space C-D: Alveolar Plateau: Alveolar gas exchange D: End of Exhalation: Point where etco 2 is measured D-E: Inspiration, rapid decrease of CO 2 ACLS Circular Algorithm Reprinted with permission. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, Part 8: Adult Advanced Cardiovascular Life Support Circulation. 2010;122(suppl 3):S729-S767. 2010 American Heart Association, Inc. 11
2010 American Heart Association (AHA) Guidelines for CPR and ECC Continuous quantitative waveform capnography is now recommended for intubated adult patients throughout the peri-arrest period. When quantitative waveform capnography is used for adults, applications now include recommendations for: confirming endotracheal tube placement monitoring CPR quality detecting ROSC (Return of Spontaneous Circulation) Endotracheal Tube (ETT) Placement Advanced Cardiovascular Life Support (ACLS) Continuous waveform capnography is recommended in addition to clinical assessment as the most reliable method of confirming and monitoring correct placement of an endotracheal tube (Class I) 12
Endotracheal Tube (ET) Placement Pediatric Advanced Life Support (PALS) Exhaled CO2 detection (capnography or colorimetry) is recommended as confirmation of tracheal tube position for neonates, infants, and children with a perfusing cardiac rhythm in all settings (Class I) Why? 26 13
Confirmation of ETT Placement Reprinted with permission. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, Part 8: Adult Advanced Cardiovascular Life Support Circulation. 2010;122(suppl 3):S729-S767. 2010 American Heart Association, Inc. Confirm ET Tube Placement 108 patients intubated in the Field 52 trauma patients 56 medical patients ET tube placement checked on arrival at the ED 27 patients (25%) had improperly placed ET tube 18 were in the esophagus 9 in oropharynx with tip above the cords Source: Falk J, Sayre MR. Confirmation of Airway Placement, Prehospital Emergency Care. 1999 ; 3:273-278 28 14
Recognizing Misplaced ETTs 152 patients requiring intubation compared to 108 from prior study. For the patients monitored with continuous capnography the rate of unrecognized misplaced tubes was 0%! The problem (unrecognized misplaced ETTs) was eliminated in in the group in whom the protocol for continuous EtCO 2 where adhered to. Silvestri S, et.al, Improvement in Misplaced Endotracheal Tube Recognition with in a Regional Emergency Medical Service, Academic Emergency Medicine, 10(5), 445. 2003. 29 Confirm ET Tube Displacement ET tube placement in esophagus may briefly detect CO 2 Following carbonated beverage ingestion When gastric distention was produced by mouth to mouth ventilation CO 2 detection will disappear after 6 positive pressure breaths 15
Monitoring Placement Routine High risk of displacement: Intra-hospital transport During procedures (CT scan) Inter-facility transport Confined spaces Patient entrapment Transport 16
Extubation Hypoventilation 17
Hypoventilation Hyperventilation 18
COPD/Bronchospasm COPD/Bronchospasm 19
Rebreathing of co 2 Spontaneous Respirations over Ventilator 20
Effectiveness of Chest Compressions Blood must circulate through the lungs for CO 2 to be exhaled and measured Ineffective chest compressions associated with low etco 2 If PETCO 2 is <10 mm Hg, it is reasonable to consider trying to improve CPR quality by optimizing chest compression parameters CPR Quality and ROSC Detection Advanced Cardiovascular Life Support (ACLS) It is reasonable to consider using quantitative waveform capnography in intubated patients to monitor CPR quality, optimizing chest compressions, and detect ROSC (Class IIb) Pediatric Advanced Life Support (PALS) Continuous capnography, if available, may be beneficial during CPR to help guide therapy, especially the effectiveness of chest compressions (Class IIa) 21
Optimization of Compressions and ROSC Chest Compressions Optimization of compression depth and rate Detect provider fatigue Ineffective compressions associated with low etco2 ROSC Rise in etco2 prior to clinical identification of ROSC May reduce interruptions of compressions for pulse check Persistently low values may suggest ROSC unlikely CPR: Assess Chest Compressions High linear correlation between EtCO 2 and cardiac output Decrease in EtCO 2 reflects a critical reduction of cardiac output Low cardiac output reduces alveolar blood flow Fails to clear CO 2 in the systemic Source: Weil MH. Cardiac Output and end-tidal carbon dioxide, Critical Care Medicine. 1985; 13(11):907-909 22
Return of Spontaneous Circulation (ROSC) ROSC may cause abrupt increase in etco 2 If PETCO 2 abruptly increases to a normal value (35 to 40 mm Hg), it is reasonable to consider that this is an indicator of ROSC Falling cardiac output or re-arrest causes decrease in etco 2 CPR: Detect ROSC 90 prehospital patients intubated in the field 16 survivors In 13 survivors a rapid rise on CO 2 production was the earliest indicator of ROSC. Before a palpable pulse Prior to blood pressure Source: Wayne MA Use of End-tidal Carbon Dioxide to Predict Outcome in Prehospital Cardiac Arrest. Annals of Emergency Medicine. 1995; 25(6):762-767 23
etco 2 During CPR Onset of arrest etco 2 Decreases During CPR etco 2 Increases Slightly ROSC etco 2 Markedly Increases ROSC (cont d) etco 2 Falls Slightly CPR and ROSC Reprinted with permission. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, Part 8: Adult Advanced Cardiovascular Life Support Circulation. 2010;122(suppl 3):S729-S767. 2010 American Heart Association, Inc. 24
Early detection of Cardiac Arrest Onset of arrest etco 2 Decreases Hypoperfusion 25
Case study A patient with a witnessed v-fib cardiac arrest has been intubated with manual ventilation, first round of ACLS medications have been administered IV and CPR is in progress. The following capnograph is displayed on the monitor. What does this suggest? What intervention would be indicated? Case study ROSC This waveform may indicate a return of spontaneous circulation (ROSC). Stop CPR, check for pulse. If pulse present, being post resuscitation care. 26
Case study An intubated patient who is status post cardiac arrest is being monitored and awaiting transfer to the ICU. The following is observed on the monitor. What does this suggest? What intervention would be indicated? Case study- Peri-arrest This waveform suggests a decrease in cardiac output and may be an early indication that the patient may go into cardiac arrest. The patient should be immediately assessed and interventions to increase cardiac output started without delay. 27
Case study An intubated patient is mechanically ventilated on a portable ventilator during a head CT scan. While the patient is in the CT scanner, the following is observed on the monitor. What does this waveform suggest? What interventions are indicated? Case study - extubation This waveform suggests either extubation, disconnection of the circuit or a kink in the sampling line. The patient should be assessed for correct ETT placement and the circuit examined. 28
Case Study Mayo Clin Proc. 2011;86(6):544-548 Case Study 54-year-old man with no known cardiac disease collapsed out- doors in a small rural community. The cardiac arrest was witnessed, and immediate cardiopulmonary resuscitation started. First responders arrived with an automated external defibrillator. Ventricular fibrillation was documented. First responders delivered 6 defibrillation shocks, 4 of which transiently restored an organized electrocardiographic rhythm but with no pulse at any time. 29
Case Study Advanced life support (ALS) flight crew arrives and initiated ALS care. The trachea was intubated, ventilation controlled, and end-tidal carbon dioxide tension continuously monitored. Antiarrhythmic and inotropic drugs were administered. An additional 6 shocks were delivered. End-tidal carbon dioxide measurements confirmed good pulmonary blood flow with chest compressions. Initial measurement was 30 mm Hg; indicating high quality CPR efforts. Case Study Resuscitation was continued until a stable cardiac rhythm was restored after 96 minutes of pulselessnes. Patient experienced a complete neurologic recovery to his pre-cardiac arrest state. To our knowledge, this is the longest duration of pulselessness in an out- of-hospital arrest with a good outcome. Good pulmonary blood flow was documented throughout by end-tidal carbon dioxide measurements. 30
Case Study The take home lessons! Value of capnography in: monitoring quality of CPR efforts detection of ROSC prediction of outcome when to continue efforts Conclusion The new 2010 guidelines from the American Heart Association (AHA) and European Resuscitation Council (ERC) for cardiopulmonary resuscitation (CPR) expressly validate the value and significance of waveform capnography in saving lives. The AHA and ERC now recommend capnography to confirm and monitor endotracheal tube placement, assess the quality of CPR, and detect return of spontaneous circulation (ROSC). Healthcare facilities and providers that resuscitate patients will now require the use of capnography in adhering to AHA and ERC guidelines. Confidential & Proprietary 31
Thank you! 32