Cutaneous microcirculatory disturbances are reversible in the early post-resuscitation period after asphyxial cardiac arrest.

Abstract

Background: Despite successful resuscitation from cardiac arrest (CA), patients often develop a fatal post-resuscitation syndrome due to ischemia-reperfusion injury. The disruption of hemodynamic coherence, where restored macrocirculation fails to improve microcirculation, leads to persistent tissue hypoperfusion and organ failure, making early non-invasive assessment of the microvasculature crucial for detecting these post-resuscitation disturbances. This study aimed to identify markers of peripheral circulatory disturbances in the early post-resuscitation period after asphyxial CA in rats.

Methods: The study was performed on adult male Wistar rats randomized into two groups: group I-sham operated animals (Sham group), group II-asphyxial CA followed by resuscitation (CA group). Asphyxial CA was induced by cessation of ventilation. Resuscitation was performed 2 minutes after actual CA. Invasive blood pressure, skin perfusion (M) assessed by laser Doppler flowmetry and cutaneous vascular conductance (CVC) were measured at baseline, 10 and 120 min after return of a spontaneous circulation (ROSC). In addition, the variables of cutaneous post-occlusive reactive hyperemia (PORH) were calculated.

Results: At 10 minutes after ROSC, there were no differences in mean arterial pressure (MAP) values in the "CA" group compared to the "Sham" group [MAP 67.3 (61.52, 82.35) vs. 60.39 (58.54, 72.03), P=0.47, respectively]. M and CVC were decreased in the "CA" group compared to the "Sham" group [M 10.1 (7.0, 12.5) vs. 14.7 (12.1, 16.5) PU, P=0.001; CVC 0.12 (0.11, 0.21) vs. 0.21 (0.19, 0.24), P=0.005, respectively]. 120 min after ROSC, the studied groups did not differ in hemodynamic parameters and in basic microcirculatory parameters. The groups also did not differ (P>0.05) in the values of PORH variables.

Conclusions: Microcirculatory disturbances in the first minutes after ROSC are manifested by a decrease in M and CVC. These pathological alterations largely reversed 2 hours after resuscitation. The use of LDF with an occlusion test did not reveal specific changes in skin PORH variables at this time. We suggests that microcirculatory assessment might have its greatest diagnostic value in the very early phase (first minutes to hours) after ROSC, while its prognostic value might require later assessments (beyond 2 hours).