Improving access to extracorporeal membrane oxygenation for out of hospital cardiac arrest: pre-hospital ECPR and alternate delivery strategies

Table 1 Components of the time from arrest to ECMO flow under each ECPR delivery strategy for a patient in zone i accessing ECPR located in zone j

	In-hospital	Rendezvous	Pre-hospital
Ambulance to patient	t_hi	t_hi	t_ji
On-scene and loading	t_s	t_s	–
Ambulance to hospital	t_ij	t_ik	–
ECMO team to hospital	–	t_jk	–
Cannulation	t_c	t_c	t_c
Arrest to flow time, T_i	\(\mathop {\min }\limits_{{j,y_{j} \ne 0 }} \left( {t_{hi} + t_{s} + t_{ij} + t_{c} } \right)\)	\(\mathop {\min }\limits_{{j,y_{j} \ne 0 }} \mathop {\min }\limits_{{k,y_{k} \ne 0}} \left( {\max \left( {t_{hi} + t_{s} + t_{ik} ,t_{jk} } \right) + t_{c} } \right)\)	\(\mathop {\min }\limits_{{h,y_{h} \ne 0 }} \left( {t_{ji} + t_{c} } \right)\)

In the rendezvous strategy, the patient and the ECPR team meet at an intermediate location k, where y_k = 1 indicates that zone k contains a suitable emergency department. The bottom row shows the total time from arrest to flow

ISSN: 1757-7241