Microcirculatory Alterations in Traumatic Hemorrhagic Shock*

Abstract

Alterations of microcirculation in traumatic hemorrhagic shock patients result from the interplay among hemorrhage-induced tissue hypoperfusion, trauma injuries, inflammatory response, and subsequent resuscitation interventions. Despite restoration of the macrocirculation, the sublingual microcirculation was impaired for at least 72 hours. The initial proportion of perfused vessels appears to be a good predictor of high Sequential Organ Failure Assessment score at D4. Further studies are required to firmly establish the link between microvascular alterations and organ dysfunction in traumatic hemorrhagic shock patients.

Effets des vasoconstricteurs sur la microcirculation

“…Une première étude chez des patients en choc hémorragique traumatique est réalisée en comparaison à des contrôles sains. Même lorsque la microcirculation évaluée par vidéomicros-copie sublinguale est bien altérée lors du choc hémorragique, les auteurs ne retrouvent pas de corrélation entre les taux de noradrénaline et les altérations microcirculatoires [5].…”

“…Le sepsis sévère a été le premier champ d'investigation clinique [3,4] et a de ce fait été étudié de façon plus exhaustive. Il existe des anomalies retrouvées dans le choc hémorragique [5], lors de l'insuffisance cardiaque aiguë [6]. Dans l'étude de prévalence chez des patients de réanimation « tout-venant » d'anomalies microcirculatoires (étude multicentrique) -microSOAP [7] -, on retrouve 17 % d'anomalies microcirculatoires sublinguales (le site le plus étudié).…”

Could resuscitation be based on microcirculation data? No

“…The addition of a new modality within the scope of resuscitative care must first be shown to improve the accuracy of diagnostic assessment. Although investigators have reported that poor microcirculatory parameters have an association with worse clinical outcomes [8,9], there is uncertainty about whether treatments targeted at microcirculatory parameters have any bearing on clinical outcomes. Within the framework of early goal-directed therapy (EGDT), patients with more favourable microcirculation data have been reported to have superior clinical outcomes in an observational study [10].…”

Macro-hemodynamic targets and hemostatic effects of fluid resuscitation during experimental hemorrhagic shock

“…were successful in restoring systemic hemodynamic parameters (HR, MAP, CI and lactate) by applying fluids, blood, and vasoactive medication in the resuscitation phase [60]. However, despite the almost immediate correction of cardiac output and arterial pressure, the sublingual microcirculation took up to 4 days to recover, with the length of time to recover correlating with the occurrence of organ dysfunction [60].…”

“…However, despite the almost immediate correction of cardiac output and arterial pressure, the sublingual microcirculation took up to 4 days to recover, with the length of time to recover correlating with the occurrence of organ dysfunction [60]. With the introduction of a new generation of hand-held microscopy at the bedside, the nature of microcirculatory alterations has been elucidated and it opens the way to enabling titration of fluids to optimally recruit the microcirculation in such a way as to optimize its oxygen transport capacity [61].…”