Interesting Capnography Cases Mike McEvoy, PhD, NRP, RN, CCRN Cardiac Surgical ICU RN & Chair Resuscitation Committee Albany Medical Center EMS Coordinator Saratoga County, NY www.mikemcevoy.com
Outline CPR Airway placement Bronchospasm PE CO Sedation DKA CPAP/BiPAP
Infrared Spectroscopy CO 2 absorbs 4.26 µm wavelength Infrared light aimed at sample Infrared sensors detect absorption and calculate CO 2
Waveform Capnography EtCO2
Back to CO 2 What does exhaled CO 2 tell us? 1. Ventilation 2. Perfusion 3. Metabolism
AHA Guidelines 2010 Continuous quantitative waveform capnography recommended for intubated patients throughout periarrest period. In adults: 1. Confirm ETT placement 2. Monitor CPR quality 3. Detect ROSC with EtCO 2 values
Goals During Cardiac Arrest Try to maintain a minimum EtCO 2 of? 10 mmhg Push HARD (> 2 or 5 cm) FAST (at least 100) Change rescuer Every 2 minutes
Code Team: CPR in progress Compression depth Compression rate Compressor Extreme acidosis Futility Other?
High-Quality CPR = CO2
CPR What Causes This? Notice the small ripples? Compressions generate air movement this expels CO 2
CPR in Progress Sudden increase in EtCO 2 Likely suggests ROSC
What else would EtCO 2? Bicarb administration CPR in progress:
What else would EtCO 2? Immediately after bicarb given:
What else would EtCO 2? Return to slightly > baseline (5 min):
Post-arrest (ROSC) patient HR 103, SpO2 99%, NIBP 102/54 What other info would you like?
Intubation 86 yo s/p open AAA, severe SOB, just reintubated HR 128, RR 14 by BVM, SpO 2 99% Esophageal intubation 6 breaths to evacuate gastric CO 2
Ventilator Patient 45 yo auto-pedestrian, open abdomen, on CRRT, BP 120/60 (80), HR 90, SpO2 97%, EtCO2 45 Normal waveform
Transport to CAT Scan Your vent patient needs a head CT. After placing her in the scanner, you see this on the capnography: What happened? When is this most likely to occur? Tubes most commonly displace during patient movement
What about the Pulse Ox? Sp0 2 98 SpO 2 will not drop for several minutes (5+ minutes)
Same Patient - SOB 81 yo COPD & heart failure Acutely SOB Slow upstroke = bronchospasm
(alpha angle) Capnogram Angles (beta angle) normal = 100 110 Airway obstruction will normal = 90 Rebreathing will
Bronchospasm Asthma, COPD Elevation of angle, loss of alveolar plateau ( shark-fin appearance) Degree of angle = severity
Effects of Treatments
Air Trapping Emphysema is results in prolonged expiration Increases angle:
Air Trapping Severe, prolonged E time
Adult Rapid Response 81 yo COPD & heart failure Acutely SOB Normal waveform, hyperventilation? Pulmonary edema
R/O Pulmonary Embolus 30 yo female smoker on BCP, SOB 104/80, P 110, 85% on NRBM 7.38, 70, 38, 22, -2.0, 85%
PE? Same patient (same VS & ABG) 104/80, P 110, 85% on NRBM 7.38, 70, 38, 22, -2.0, 85%
Alveolar Perfusion A-a gradient (EtCO 2 < PaCO 2 )
Rapid Response: RN Worried You are called to see a 75 yo heart failure pt. with general weakness She is cool, BP 80/50, HR 128 afib What does the capnography say? Cardiogenic Shock!
Classic I don t feel well You don t look well, either
MSOF Patient 81 yo MSOF patient multiple drips BP falling, not responding to pressors
Unconscious? 32 yo unresponsive after ketamine and fentanyl for hip reduction Hypoventilation (? pharmaceutical) Use capnography on EVERY conscious sedation patient!
ICU Admission You admit a 23 yo GSW to the head to your neurosurgical ICU He is intubated and sedated: EtCO 2 = 35, RR = 24 Curare Cleft = diaphragmatic movement (breathing over drugs)
ICU Admission You don t make any changes The patient appears to awaken: EtCO 2 = 30, RR = 38 Curare Cleft = diaphragmatic movement (breathing over drugs) Bucking ventilation needs drug tx
Post Cardiothoracic Surgery 59 yo POD #1, s/p CABGx5 Extubated, 2L n/c, VSS, no issues Cardiac oscillations cardiac pressures being transmitted to airway (ripple effect)
17 yo pt. in DKA You admit a patient from the ED in DKA The patient is alert and oriented; blood sugar is reportedly 880 ph? 6.93
Perfusion, acidosis and ph Cardiac arrest = no CO 2 Capnography reflects perfusion cardiac output = EtCO 2 CO 2 is transported in the blood as bicarbonate (HCO 3 ) In severe acidosis, HCO 3 = EtCO 2
Peds Step Down Floor 14 yo asthmatic severely SOB Hyperventilation No evidence of airway obstruction or air trapping
Intubation Anesthesia reintubates This is the capnography waveform: Is the tube in? Is the ventilation rate and depth appropriate?
Titration of NIV PNA vs. CHF BiPAP tx
Nasal Capnography Requires cannula w/ pillow (oral)
Rounded Waveforms Be suspicious of rounded waveforms: These often imply low perfusion, acidosis, sepsis, poisoning or other metabolic derangements
Questions? Thanks for your attention! Slides posted at: www.mikemcevoy.com