Capnography in electrophysiology

Capnography waveforms have proven invaluable in early detecting adverse events during procedural sedation, like airway obstruction, hypoventilation and both mild (<90% SpO₂) and severe hypoxemia (<85% SpO₂).^4,5

Capnography detects respiratory depression at a median of 60s (5-240s) prior to pulse oximetry⁶ and can increase patient safety. Consequently, various international guidelines advise to monitor patients´ ventilation during procedural sedation with capnography.⁷ The Academy of Medical Royal Colleges (UK) recommends the use of capnography to monitor ETCO₂ and ventilation in its guidelines for safe sedation with propofol during cardiac procedures⁸. Additionally, capnography aids in assessing the effectiveness of interventions, such as analgesia administration, to ensure optimal sedation levels are maintained⁹. Yet, etCO₂ monitoring still appears to be underutilised in the electrophysiology lab.

In the context of electrophysiology procedures like cryoballoon ablation for atrial fibrillation (AF), capnography plays a role in monitoring cryoballoon-to-pulmonary vein (PV) occlusion. By measuring etCO₂ and analyzing capnography waveforms, healthcare providers can gauge the occlusion status and evaluate pulmonary blood flow.¹⁰ Capnography monitoring during PV procedures can therefore assess the success of cryoballoon-to-pulmonary vein (PV) occlusion and monitor right phrenic nerve function. This real-time assessment has emerged as an early warning indicator¹¹ and a predictor of long-term efficacy¹⁰ with patients that maintained normal sinus rhythm (NSR).¹⁰ Early detection of phrenic nerve injury during cryoablation procedures can help prevent potential complications early and optimize patient outcomes. 

Capnography is a valuable technology in ensuring patient safety during procedural sedation, including electrophysiology procedures like cryoablation for atrial fibrillation (AF). By incorporating capnographic monitoring, electrophysiologists can promptly detect and address respiratory complications, optimize sedation levels, and ultimately enhance patient outcomes^4,5.

Don't compromise on patient safety in your electrophysiology lab during procedural sedation. Incorporate capnography monitoring, gain valuable insights in real-time, and optimize patient outcomes. 

References

1. Tobias, J. D., & Leder, M. (2011). Procedural sedation: A review of sedative agents, monitoring, and management of complications. Saudi journal of anaesthesia, 5(4), 395–410. https://doi.org/10.4103/1658-354X.87270

2. Jones, M. R., Karamnov, S., Urman, R. D.  (2018). Characteristics of Reported Adverse Events During Moderate Procedural Sedation: An Update. The Joint Commission Journal on Quality and Patient Safety, S1553725017304750. https://doi:10.1016/j.jcjq.2018.03.011      

3. Bhananker, S. M., Posner, K. L., Cheney, F. W., Caplan, R. A., Lee, L. A., & Domino, K. B. (2006). Injury and liability associated with monitored anesthesia care: a closed claims analysis. Anesthesiology, 104(2), 228–234. https://doi.org/10.1097/00000542-200602000-00005

4. Gallagher J. J. (2018). Capnography Monitoring During Procedural Sedation and Analgesia. AACN advanced critical care, 29(4), 405–414. https://doi.org/10.4037/aacnacc2018684

5. Saunders, R., Struys, M. M. R. F., Pollock, R. F., Mestek, M., & Lightdale, J. R. (2017). Patient safety during procedural sedation using capnography monitoring: a systematic review and meta-analysis. BMJ open, 7(6), e013402. https://doi.org/10.1136/bmjopen-2016-013402

6. Deitch, K., Miner, J., Chudnofsky, C. R., Dominici, P., & Latta, D. (2010). Does end tidal CO2 monitoring during emergency department procedural sedation and analgesia with propofol decrease the incidence of hypoxic events? A randomized, controlled trial. Annals of emergency medicine, 55(3), 258–264. https://doi.org/10.1016/j.annemergmed.2009.07.030

7. Hinkelbein, J., Lamperti, M., Akeson, J., Santos, J., Costa, J., De Robertis, E., Longrois, D., Novak-Jankovic, V., Petrini, F., Struys, M. M. R. F., Veyckemans, F., Fuchs-Buder, T., & Fitzgerald, R. (2018). European Society of Anaesthesiology and European Board of Anaesthesiology guidelines for procedural sedation and analgesia in adults. European journal of anaesthesiology, 35(1), 6–24. https://doi.org/10.1097/EJA.0000000000000683

8. Furniss, S. S., & Sneyd, J. R. (2015). Safe sedation in modern cardiological practice. Heart (British Cardiac Society), 101(19), 1526–1530. https://doi.org/10.1136/heartjnl-2015-307656

9. Gerstein, N. S., Young, A., Schulman, P. M., Stecker, E. C., & Jessel, P. M. (2016). Sedation in the Electrophysiology Laboratory: A Multidisciplinary Review. Journal of the American Heart Association, 5(6), e003629. https://doi.org/10.1161/JAHA.116.003629

10. Pickett, R. A., Owens, K., Landis, P., Sara, R., & Lim, H. W. (2018). Cryoballoon-to-Pulmonary Vein Occlusion Assessment via Capnography Technique: Where Does Occlusion Testing by End-Tidal CO2 Measurement "Fit" as a Predictor of Long-Term Efficacy?. Journal of atrial fibrillation, 11(1), 2055. https://doi.org/10.4022/jafib.2055

11. Hoyt, R.H. & Lim, H.W. 2015. Capnographic observations during cryoballoon ablation of atrial fibrillation. The Journal of Innovations in Cardiac Rhythm Management. 6(8): 2093–2099 https://doi:10.19102/icrm.2014.060805