Association between sublingual microcirculation, tissue perfusion and organ failure in major trauma: A subgroup analysis of a prospective observational study

Abstract

Introduction Previous studies described impaired microvascular perfusion and tissue oxygenation as reliable predictors of Multiple Organ Failure in major trauma. However, this relationship has been incompletely investigated. The objective of this analysis is to further evaluate the association between organ dysfunction and microcirculation after trauma. Materials and methods This is a retrospective subgroup analysis on 28 trauma patients enrolled for the Microcirculation DAIly MONitoring in critically ill patients study (NCT 02649088). Patients were divided in two groups according with their Sequential Organ Failure Assessment (SOFA) score at day 4. At admission and every 24 hours, the sublingual microcirculation was evaluated with Sidestream Darkfield Imaging (SDF) and peripheral tissue perfusion was assessed with Near Infrared Spectroscopy (NIRS) and Vascular Occlusion Test (VOT). Simultaneously, hemodynamic, clinical/laboratory parameters and main organ supports were collected. Results Median SOFA score at Day 4 was 6.5. Accordingly, patients were divided in two groups: D4-SOFA ≤6.5 and D4-SOFA >6.5. The Length of Stay in Intensive Care was significantly higher in patients with D4-SOFA>6.5 compared to D4-SOFA≤6.5 (p = 0.013). Total Vessel Density of small vessels was significantly lower in patients with high D4-SOFA score at Day 1 (p = 0.002) and Day 2 (p = 0.006) after admission; the Perfused Vessel Density was lower in patients with high D4-SOFA score at Day 1 (p = 0.007) and Day 2 (p = 0.033). At Day 1, NIRS monitoring with VOT showed significantly faster tissue oxygen saturation downslope (p = 0.018) and slower upslope (p = 0.04) in patients with high D4-SOFA. Discussion In our cohort of major traumas, sublingual microcirculation and peripheral microvascular reactivity were significantly more impaired early after trauma in those patients who developed more severe organ dysfunctions. Our data would support the hypothesis that restoration of macrocirculation can be dissociated from restoration of peripheral and tissue perfusion, and that microvascular alterations can be associated with organ failure.

Severe Impairment of Microcirculatory Perfused Vessel Density Is Associated With Postoperative Lactate and Acute Organ Injury After Cardiac Surgery

“…This study was powered on the smallest difference between pre-and postoperative perfused vessel densities and between the highest and lowest quartile of postoperative SOFA scores using microcirculatory data from previous studies. [15][16][17] The authors calculated that at least 18 patients would need to be enrolled to maintain 80% power to detect a significant difference in capillary flow, density, and SOFA scores. They increased this number to 25 patients to account for a variable magnitude of the effect.…”

Advances in translational imaging of the microcirculation

“…140 However, StO 2 -guided treatment protocols have not shown benefits over routine care, 141 which may signify a gap between the prognostic value of NIRS and its ability to influence outcomes. In addition to sepsis, the correlation of NIRS metrics with ICU outcomes has also been evaluated in the general ICU population, 142 patients with trauma, [143][144][145][146] and patients with cardiogenic shock. 147 Despite their high spatial and temporal resolutions, optical imaging modalities are still not widely used for clinical imaging of the microcirculation due to their limited tissue penetration.…”

“…However, StO 2 ‐guided treatment protocols have not shown benefits over routine care, 141 which may signify a gap between the prognostic value of NIRS and its ability to influence outcomes. In addition to sepsis, the correlation of NIRS metrics with ICU outcomes has also been evaluated in the general ICU population, 142 patients with trauma, 143–146 and patients with cardiogenic shock 147 …”

Effects of impaired microvascular flow regulation on metabolism‐perfusion matching and organ function

“…115,[226][227][228] Several strategies have been proposed and employed to address the spatial and temporal heterogeneities in flow and oxygenation ('microcirculatory shock' 229 ) seen at the microvascular level. [230][231][232][233] Methods for monitoring the microvascular response to these interventions [234][235][236] are also discussed.…”

“…Optimizing tissue oxygenation and perfusion at the microvascular level in addition to restoring systemic physiological parameters (‘hemodynamic coherence’ 225 ) is the objective of ‘microvascular resuscitation’ 115,226‐228 . Several strategies have been proposed and employed to address the spatial and temporal heterogeneities in flow and oxygenation (‘microcirculatory shock’ 229 ) seen at the microvascular level 230‐233 . Methods for monitoring the microvascular response to these interventions 234‐236 are also discussed.…”