In this episode, Alec Wilcox & I discuss ECPR eligibility & preparation. ECPR, or extracorporeal cardiopulmonary resuscitation, involves taking a patient in cardiac arrest, sucking blood from their venous system, oxygenating it externally, and then pumping it back into their arterial system. This procedure helps maintain blood circulation and oxygen delivery during cardiac arrest, serving as a bridge to further therapy.
While ECPR can be a specialized and regionally available therapy, identifying suitable candidates is crucial. Patients likely to benefit from ECPR typically include those with witnessed arrests, a short duration of no blood flow (no-flow time), and a potentially reversible cause of cardiac arrest.
Identifying ECMO Candidates Early
ECMO can serve as a vital bridge to definitive treatment for patients in cardiac arrest, especially those with shockable rhythms such as ventricular fibrillation (V-Fib) or ventricular tachycardia (V-Tach). The decision to use ECMO is based not just on age but on the overall health status of the patient and indicators of viability, such as whether the cardiac arrest was witnessed. Patients who receive immediate CPR during a witnessed arrest are often ideal candidates for ECMO, as this approach significantly enhances their chances of survival by maintaining circulatory and respiratory support while awaiting more permanent solutions.
The Critical Role of High-Quality CPR
High-quality compressions and adequate ventilation are the cornerstones of effective prehospital care for potential ECMO candidates. While there may not be much data suggesting mechanical compression devices outperform manual compressions when working an arrest on scene, there is evidence to show the degradation of manual compressions as soon as patient movement begins. Mechanical compressions allow for consistent compression quality and optimal provider safety when initiating transport.
Advanced Airway Management
Pre-hospital data has leaned towards using a supraglottic airway, such as the i-gel, which increases cardiac arrest survival. It is reasonable to place an I-gel (a supraglottic airway device) quickly on the scene to establish an airway when resources are limited, especially when preparing a patient potentially for ECMO (Extracorporeal Membrane Oxygenation). However, when feasible, there is some evidence to recommend switching from a supraglottic airway to an endotracheal tube during transport to optimize ventilation and oxygenation, which are critical for patient outcomes when receiving long durations of CPR or qualifying for ECMO.
Ventilation Effectiveness: The discussion highlights concerns about the effectiveness of ventilation through supraglottic airways. Studies cited indicate that patients intubated at the scene before ECMO had better initial blood gas levels than those with supraglottic airways, emphasizing the importance of optimal ventilation strategies during prehospital care.
Mechanical Ventilation During CPR: Avoid under-ventilating the patient, which is a risk due to increased intrathoracic pressures caused by vigorous chest compressions. The podcast mentions adjusting ventilator settings, such as turning off flow triggers and closely monitoring exhaled tidal volumes, to ensure adequate ventilation.
30:2 Ventilation Strategy: The "30 compressions to 2 ventilations" ratio is debated, especially after the placement of an advanced airway. The discussion suggests that continuing with a 30:2 mode might benefit specific ECMO transport scenarios to optimize ventilation and perfusion balance despite having an advanced airway that typically calls for continuous compressions with asynchronous ventilations.
Real-Time Adjustments and Observations: The necessity for real-time adjustments based on the patient’s condition during transport is emphasized. This includes potential shifts from supraglottic to endotracheal intubation and modifications in mechanical ventilation settings to align with the dynamic needs of a patient undergoing CPR.
Ongoing Communication and Coordination
Early alerts about a potential ECMO transfer can streamline the process, ensuring that teams are prepared for immediate intervention upon arrival. This is pivotal in reducing the time to ECMO initiation.
References:
Bartos, J. A., Clare Agdamag, A., Kalra, R., Nutting, L., Frascone, R. J., Burnett, A., Vuljaj, N., Lick, C., Tanghe, P., Quinn, R., Simpson, N., Peterson, B., Haley, K., Sipprell, K., & Yannopoulos, D. (2023). Supraglottic airway devices are associated with asphyxial physiology after prolonged CPR in patients with refractory Out-of-Hospital cardiac arrest presenting for extracorporeal cardiopulmonary resuscitation. Resuscitation, 186, 109769. https://doi.org/10.1016/j.resuscitation.2023.109769
Gyory, R. A., Buchle, S. E., Rodgers, D., & Lubin, J. S. (2017). The Efficacy of LUCAS in Prehospital Cardiac Arrest Scenarios: A Crossover Mannequin Study. The western journal of emergency medicine, 18(3), 437–445. https://doi.org/10.5811/westjem.2017.1.32575
Hoffman, D. V., Figueroa, A., Shaw, M., & McAllister, P. (2019). The Efficacy of Chest Compressions in the Bell 407. Air medical journal, 38(4), 281–284. https://doi.org/10.1016/j.amj.2019.03.015
Kiss, B., Nagy, B., Pál-Jakab, Á., Lakatos, B., Soltész, Á., Osztheimer, I., Heltai, K., Édes, I. F., Németh, E., Merkely, B., & Zima, E. (2023). Early Application of ECMO after Sudden Cardiac Arrest to Prevent Further Deterioration: A Review and Case Report. Journal of clinical medicine, 12(13), 4249. https://doi.org/10.3390/jcm12134249
Kopra, J., Litonius, E., Pekkarinen, P. T., Laitinen, M., Heinonen, J. A., Fontanelli, L., Mäkiaho, T. P., & Skrifvars, M. B. (2023). Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest. Intensive care medicine experimental, 11(1), 3. https://doi.org/10.1186/s40635-022-00485-0
Schmicker, R. H., Nichol, G., Kudenchuk, P., Christenson, J., Vaillancourt, C., Wang, H. E., Aufderheide, T. P., Idris, A. H., & Daya, M. R. (2021). CPR compression strategy 30:2 is difficult to adhere to, but has better survival than continuous chest compressions when done correctly. Resuscitation, 165, 31–37. https://doi.org/10.1016/j.resuscitation.2021.05.027
