Table 1.

Summary of studies reporting on cerebral perfusion during eCPR in humans or swine. Case reports and conference abstracts were not included.

Reference	Subjects	Method	Parameters	Timepoints	Highlights
Bělohlávek et al.91	11 pigs	NIRS, Doppler guide wire	rSO2, carotid flow velocity	Arrest	In the absence of ROSC, rSO2 and carotid flow velocity increased after initiation of VA-ECMO. Addition of IABP counterpulsation did not affect these parameters.
Spinelli et al.27	13 pigs	brain O2 tension probe, ICP catheter	PBro2, ICP, CePP	Baseline, arrest, 0–6 h eCPR	eCPR quickly restored PBro2 and CePP to pre-arrest values. ICP values remained unchanged throughout VF and early eCPR, but significantly increased after 5 h of eCPR.
Luo et al.83	18 pigs	Transit time flow probe	Carotid blood flow	Baseline, arrest, 0–6 h eCPR	Carotid blood flow was significantly reduced during low flow VA-ECMO (30–35 ml/kg/min) compared to standard flow VA-ECMO (65–70 ml/kg/min) over 6 h of eCPR.
Wollborn et al.92	29 pigs	NIRS, transcranial Doppler US	rSO2, MCA blood flow velocity	Baseline, arrest, 0–6 h post-ROSC	rSO2 recovered by 30 min post-ROSC. Mean MCA blood flow velocity was impaired at 3, and 6 h post-ROSC in animals treated with conventional CPR or eCPR.
Ölander et al.93	10 pigs	Transit time flow probe, ICP catheter	Carotid blood flow, ICP, CePP	Baseline, 15–45 min CPR, 30–180 min eCPR	Initiation of eCPR restored carotid blood flow and partially restored CePP to pre-arrest values. Minimal changes in ICP were observed throughout the study.
Levy et al.43	12 pigs	NIRS, transit time flow probe, ICP catheter, jugular venous catheter	rSO2, carotid blood flow, ICP, CePP, SjvO2, PRx	Baseline, 0–30 min eCPR, 0–120 min post-ROSC	Targeting a higher MAP (80–90 mmHg vs. 65–75 mmHg) via epinephrine transiently improved PRx during eCPR but worsened cerebral hemodynamics after ROSC.
Ölander et al.94	12 pigs	Transit time flow probe, ICP catheter	Carotid blood flow, ICP, CePP	Baseline, CPR, 0–180 min eCPR	Initiation of eCPR partially restored carotid blood flow and CePP to pre-arrest values. Minimal changes in ICP were observed throughout the study.
Yagi et al.16	15 patients with OHCA	NIRS	TOI	Arrival, post-vasopressin, 0–2 h eCPR	In 14 patients with poor neurological outcome, TOI increased after administration of vasopressin and further increased after initiation of VA-ECMO + IABP. TOI decreased during eCPR in one patient with good neurological outcome.
Ehara et al.17	16 patients with OHCA	NIRS	rSO2	CPR, 2–10 min eCPR	Initiation of eCPR increased rSO2 in patients with a poor neurological outcome. rSO2 did not change with eCPR in patients with good neurological outcome.
Bartos et al.18	83 patients with OHCA	NIRS	Not specified	0, 24, 48 h eCPR	“NIRS values” increased from baseline over the first 48 h in survivors. Values remained stable in patients that died, and values declined in patients with brain death.
Yagi et al.20	18 patients with OHCA	NIRS	TOI	CPR, 0–20 min eCPR	TOI increased immediately after initiating eCPR. Neurological outcomes were not reported.
Roellke et al.19	6 patients with IHCA	NIRS	rSO2	CPR, 2.5–5 min eCPR	rSO2 increased immediately after initiating eCPR. No patients survived to hospital discharge.

Abbreviations: CePP, cerebral perfusion pressure; CPR, cardiopulmonary resuscitation; eCPR, extracorporeal cardiopulmonary resuscitation; IABP, intra-aortic balloon pump; ICP, intracranial pressure; IHCA, in-hospital cardiac arrest; MCA, middle cerebral artery; NIRS, near-infrared spectroscopy; OHCA, out-of-hospital cardiac arrest; PRx, pressure reactivity index; rSO₂, regional oxygen saturation; SjvO2, jugular venous oxygen saturation; StO₂, tissue hemoglobin saturation; TOI, tissue oxygenation index; VA-ECMO, veno-arterial extracorporeal membrane oxygenation; VF, ventricular fibrillation.