Microcirculatory blood flow during cardiac arrest and cardiopulmonary resuscitation does not correlate with global hemodynamics: an experimental study

Abstract

BackgroundCurrent research highlights the role of microcirculatory disorders in post-cardiac arrest patients. Affected microcirculation shows not only dissociation from systemic hemodynamics but also strong connection to outcome of these patients. However, only few studies evaluated microcirculation directly during cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). The aim of our experimental study in a porcine model was to describe sublingual microcirculatory changes during CA and CPR using recent videomicroscopic technology and provide a comparison to parameters of global hemodynamics.MethodsCardiac arrest was induced in 18 female pigs (50 ± 3 kg). After 3 min without treatment, 5 min of mechanical CPR followed. Continuous hemodynamic monitoring including systemic blood pressure and carotid blood flow was performed and blood lactate was measured at the end of baseline and CPR. Sublingual microcirculation was assessed by the Sidestream Dark Field (SDF) technology during baseline, CA and CPR. Following microcirculatory parameters were assessed off-line separately for capillaries (≤20 µm) and other vessels: total and perfused vessel density (TVD, PVD), proportion of perfused vessels (PPV), microvascular flow index (MFI) and heterogeneity index (HI).ResultsIn comparison to baseline the CA small vessel microcirculation was only partially preserved: TVD 15.64 (13.59–18.48) significantly decreased to 12.51 (10.57–13.98) mm/mm2, PVD 15.57 (13.56–17.80) to 5.53 (4.17–6.60) mm/mm2, PPV 99.64 (98.05–100.00) to 38.97 (27.60–46.29) %, MFI 3.00 (3.00–3.08) to 1.29 (1.08–1.58) and HI increased from 0.08 (0.00–0.23) to 1.5 (0.71–2.00), p = 0.0003 for TVD and <0.0001 for others, respectively. Microcirculation during ongoing CPR in small vessels reached 59–85 % of the baseline values: TVD 13.33 (12.11–15.11) mm/mm2, PVD 9.34 (7.34–11.52) mm/mm2, PPV 72.34 (54.31–87.87) %, MFI 2.04 (1.58–2.42), HI 0.65 (0.41–1.07). The correlation between microcirculation and global hemodynamic parameters as well as to lactate was only weak to moderate (i.e. Spearman’s ρ 0.02–0.51) and after adjustment for multiple correlations it was non-significant.ConclusionsSublingual microcirculatory parameters did not correlate with global hemodynamic parameters during simulated porcine model of CA and CPR. SDF imaging provides additional information about tissue perfusion in the course of CPR.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0934-5) contains supplementary material, which is available to authorized users.

Monitoring coherence between the macro and microcirculation in septic shock

“…In acute models of hemorrhagic shock, tamponade, cardiogenic shock and cardiac arrest coherence exists during the development of shock. In other words, during the development of shock, as signaled by the changes in macrocirculatory parameters, also the microcirculation shows abnormal perfusion parameters [19][20][21][22][23][24][25][26][27]. Although during the development of septic shock, characterized by hypotension and decreased cardiac output (CO), hemodynamic coherence is present [20, [28][29][30].…”

“…As argued earlier, the absence of coherence in this phase may have significant effects on the adequacy of resuscitation as it may result in both over-resuscitation and under-resuscitation. It is clear from experimental models in many different pathophysiologic conditions, including sepsis, that resuscitation on global hemodynamic parameters frequently fails to restore microcirculatory perfusion and oxygenation [25,28,[45][46][47]. The effects in different microcirculatory systems or even within one microcirculatory system may however not be similar [30,48].…”

Impact of donor cardiopulmonary resuscitation on the outcome of simultaneous pancreas–kidney transplantation—a retrospective study

“…Several animal models have already indicated that such preconditioning is also possible in interventions involving the pancreas, and has a protective effect against postoperative complications . Even if CPR is adequately administered or is uninterrupted, the macro‐ and microcirculation produced does not reach physiological baseline levels and the patient will undergo a relative ischemia or insufficient blood supply . We therefore propose that CPR itself could be a potential trigger for ischemic tissue preconditioning, which could confer subsequent protection from RI and from further ischemia.…”

Brain perfusion evaluated by regional tissue oxygenation as a possible quality indicator of ongoing cardiopulmonary resuscitation. An experimental porcine cardiac arrest study

“…We used a similar anesthesia protocol, animal preparation and study outline, including data acquisition methods, as described in our previous study. 7 Briefly, the study was performed on 24 domestic pigs (16 – 20 weeks, weighing 50±3 kg). Anesthesia was initiated by a propofol bolus (2 mg/kg) and continued by the intravenous infusion of propofol (6-8 mg/kg/h), midazolam (0.1 - 0.2 mg/kg/h) and morphine (0.1 - 0.2 mg/kg/h).…”