Capnography Could Make You a Rock Star! Mike McEvoy, PhD, RN, CCRN, NRP Staff RN – CTICU and Resuscitation Committee Chair Albany Medical Center, New York EMS Coordinator – Saratoga County, New York EMS Editor – Fire Engineering magazine
Learning Objectives Upon completion of the presentation the participant will Explain the physiology of capnography Discuss the clinical value of capnography in improving patient outcomes Recall the role of capnography in the Guidelines for Emergency Cardiac Care and CPR
What is Capnography? Available for spontaneously breathing and for intubated patients
Uses Circuit Plugged into Monitor
Produces Waveform
Capnography “Capnos” = Greek for smoke From the “fire of life” metabolism CO 2 = the waste product of metabolism Carbon Dioxide is a compound molecule 2 oxygen + 1 carbon 0.03% concentration in room air Odorless; heavier than air Green plants scavenge excess CO 2
Oxygen Lungs alveoli blood Muscles + Organs Oxygen Cells Oxygen + Glucose ENERGY CO 2 Blood Lungs CO 2 Breath CO 2 Physiology of Metabolism
SpO 2 versus EtCO 2 Oxygenation (Pulse Ox) O 2 for metabolism SpO 2 measures % of O 2 in RBCs Changes within 5 minutes Ventilation (Capnography) CO 2 from metabolism EtCO 2 measures exhaled CO 2 at point of exit Changes within 10 seconds
Oxygen Lungs alveoli blood Muscles + Organs Oxygen Cells Oxygen + Glucose ENERGY CO 2 Blood Lungs CO 2 Breath CO 2 Physiology of Metabolism
Normal Capnography Waveform Normal range is mmHg Height = total CO2 Length = time/rate 45 0
Capnography Waveforms Hypoventilation Normal Hyperventilation 45 0
Capnogram Phases Inhale End-tidal AB C D E
Capnogram Phases End-tidal Begin Exhale (dead space) AB C D E
Capnogram Phases End-tidal End Exhale (plateau) AB C D E
Capnogram Phases End-tidal End of the Wave of Exhalation AB C D E
98 Sp0 2 The tube came out! What about the Pulse Ox? What Happened?
Waveform Shape
Bronchospasm (Asthma) MildModerate
Test Capnography waveforms Normal Hyperventilation Hypoventilation Bronchospasm
Guidelines 2000 EtCO 2 can be useful as a non-invasive indicator of cardiac output generated during CPR
Carbon Dioxide (CO 2 ) Production
What If…
But, with High-Quality CPR…
Meet Howard Snitzer 54-years old, collapsed Jan 5, 2011 outside Don’s Foods in Goodhue, MN (pop. 900) 2 dozens rescuers took turns providing CPR for 96 minutes 6 shocks with first responder AED, 6 more shocks by Mayo Clinic Air Flight Medics Transported to Mayo Clinic Cardiac Cath Lab
Why Not Quit? Thrombectomy and stent to LAD 10 days in Mayo Clinic “The capnography told us not to give up” EtCO 2 averaged 35 (range 32 – 37)
Decision to Call the Code 120 prehospital patients in non-traumatic cardiac arrest EtCO 2 had 90% sensitivity in predicting ROSC Maximal level of <10mmHg during the first 20 minutes after intubation was never associated with ROSC *Source: Canitneau J. P End-tidal carbon dioxide during cardiopulmonary resuscitation in humans presenting mostly with asystole, Critical Care Medicine 24:
So What’s the Goal During CPR? Try to maintain a minimum EtCO 2 of 10 Push HARD (> 2”) FAST (at least 100) Change rescuer Every 2 minutes
AHA Hospital Guidelines – just released (2013) Pre, Intra, Post arrest recommendations: 1.Real time feedback at the point of care 2.Shock early, don’t interrupt CPR, avoid hyperventilation, optimize depth 3.BENCHMARK
AHA Hospital Guidelines – just released (2013) Pre, Intra, Post arrest recommendations: 1.Real time feedback at the point of care 2.Shock early, don’t interrupt CPR, avoid hyperventilation, optimize depth 3.BENCHMARK
AHA Guidelines – just released (2013) Pre, Intra, Post arrest recommendations: 1.Real time feedback at the point of care 2.Shock early, don’t interrupt CPR, avoid hyperventilation, optimize depth 3.BENCHMARK
AHA Guidelines – just released (2013) Pre, Intra, Post arrest recommendations: 1.Real time feedback at the point of care 2.Shock early, don’t interrupt CPR, avoid hyperventilation, optimize depth 3.BENCHMARK
AHA Guidelines – just released (2013) Pre, Intra, Post arrest recommendations: 1.Real time feedback at the point of care 2.Shock early, don’t interrupt CPR, avoid hyperventilation, optimize depth 3.BENCHMARK
Anesthesia
What Should Happen Lungs (Good) $tomach (Bad, Very Bad )
Anesthesia Litigation
Respiratory Damaging Events American Society for Anesthesiologists: Closed Claims Project Database, 2010
The Answer? Capnography Oct 1986 – American Society of Anesthesiology (ASA) Capnography = basic standard of care for intra-operative monitoring ColorimetricCapnometryWaveform Capnography
Recent Need for EtCO 2
Guidelines 2005 EtCO 2 recommended to confirm ET tube placement
Capnography Detects ROSC Indications of Return of Spontaneous Circulation Sudden, sustained rise in EtCO 2 from baseline Can occur before pulse or blood pressure are palpable
EtCO 2 to Detect ROSC 90 pre-hospital intubated arrest patients 16 survivors 13 survivors: Rapid rise in exhaled CO 2 was the earliest indicator of ROSC Before pulse or blood pressure were palpable Wayne MA, Levine RL, Miller CC. “Use of End-tidal Carbon Dioxide to Predict Outcome in Prehospital Cardiac Arrest”. Annals of Emergency Medicine. 1995; 25(6): Levine RL., Wayne MA., Miller CC. “End-tidal carbon dioxide and outcome of out-of-hospital cardiac arrest.” New England Journal of Medicine. 1997;337(5):
Guidelines 2010 Continuous quantitative waveform capnography recommended for intubated patients throughout peri-arrest period In adults: 1.Confirm ETT placement 2.Monitor CPR quality 3.Detect ROSC with EtCO 2 values
Guidelines 2010 Evidence Capnography Classes and Levels of Evidence 1.Confirm ETT placement: Class I, LOE A 2.Monitor CPR quality: Class IIb, LOE C 3.Detect ROSC with EtCO2 values: Class IIa, LOE B
Definition of Classes and Levels of Evidence Used in AHA Recommendations Class I Conditions for which there is evidence for and/or general agreement that the procedure or treatment is useful and effective. Class II Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. Class IIa The weight of evidence or opinion is in favor of the procedure or treatment. Class IIb Usefulness/efficacy is less well established by evidence or opinion. Class III Conditions for which there is evidence and/or general agreement that the procedure or treatment is not useful/effective and in some cases may be harmful. Therapeutic Recommendations Level of Evidence A Data derived from multiple randomized clinical trials or meta-analyses Level of Evidence B Data derived from a single randomized trial or nonrandomized studies Level of Evidence C Consensus opinion of experts, case studies, or standard of care Diagnostic Recommendations Level of Evidence A Data derived from multiple prospective cohort studies using a reference standard applied by a masked evaluator Level of Evidence B Data derived from a single grade A study, or one or more case-control studies, or studies using a reference standard applied by an unmasked evaluator Level of Evidence C Consensus opinion of experts ©2010 American Heart Association, Inc. All rights reserved.Goldstein et al. Published online in Stroke Dec. 2, 2010
Classes of Evidence I.Standard of care: Just do it! II.Conflicting evidence: Maybe, maybe not IIa. Evidence favors benefit – Do it IIb. Evidence not so favorable – Think first III.Not useful, maybe harmful: Don’t do it
Levels of Evidence Proof A.A whole lotta proof: Best! B.Some proof: Better than nothing C.No proof: But some like the idea
Guidelines 2010 Evidence Capnography Classes and Levels of Evidence 1.Confirm ETT placement: Class I, LOE A Just do it, best proof 2.Monitor CPR quality: Class IIb, LOE C Think first, some like the idea 3.Detect ROSC with EtCO2 values: Class IIa, LOE B Do it, better than nothin’
Must We Follow Evidence? BMJ, Dec 2003 Published cases of survivors falling from airplanes No published evidence parachutes actually work
Guidelines 2010 Evidence Capnography Classes and Levels of Evidence 1.Confirm ETT placement: Class I, LOE A Just do it, best proof 2.Monitor CPR quality: Class IIb, LOE C Think first, some like the idea 3.Detect ROSC with EtCO2 values: Class IIa, LOE B Do it, better than nothin’ ?
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Questions?