Association between haemodynamics during cardiopulmonary resuscitation and cerebral arterial enhancement

The extent to which antegrade or retrograde blood flow occurs during cardiopulmonary resuscitation (CPR) remains unclear. We investigated the relationship between arterial-venous pressure conditions during CPR and cerebral arterial enhancement on contrast-enhanced computed tomography (CT) to identify haemodynamic parameters associated with antegrade cerebral blood flow.

This prospective observational single-centre study included adult patients with non-traumatic out-of-hospital cardiac arrest who did not achieve return of spontaneous circulation and underwent contrast-enhanced CT after CPR termination. Femoral arterial and venous pressures were continuously recorded during LUCAS 3-assisted chest compressions. Analysed parameters included arterial systolic (A sys), mean (A mean), diastolic (A dias) pressures, and arterial-venous pressure gradients (ΔSys A-V and ΔMean A-V). Contrast enhancement of the circle of Willis was evaluated.

Among 38 patients, 11 (29%) demonstrated contrast enhancement of the circle of Willis. Higher A sys, A mean, ΔSys A-V, and ΔMean A-V were significantly associated with cerebral arterial enhancement (all p < 0.001). The proportion of patients with arterial enhancement increased with higher ΔMean A-V, and all patients with ΔMean A-V ≥ 20 mmHg showed complete arterial enhancement. Venous enhancement from the superior sagittal sinus to the inferior vena cava was observed in nearly all patients.

Higher arterial pressures and greater arterial-venous pressure gradients were associated with cerebral arterial enhancement during CPR, suggesting that a mean arterial-venous pressure gradient may be associated with antegrade cerebral perfusion and represent a physiological target for optimising resuscitation.