Microcirculatory investigation in severe trauma injury

Introduction

Disturbances of regional microcirculation do not correlate with the global indices of perfusion such as the cardiac index and cardiac output. Research of local regional microcirculation must therefore be useful for diagnostic and prognostic value. The aim of study was to research the diagnostic and prognostic consequence of the microcirculatory indices in severe trauma injury.

Methods

Thirty-four patients with severe trauma injury were entered into a prospective trial (scale TRISS, excluding patients with penetrating trauma and severe head injury). The patients were divided into two groups according to the TRISS scale: group 1 (TRISS 10–15 points, lethal probability 30%, favorable outcome) and group 2 (TRISS 16–25 points, lethal probability >30%, unfavorable outcome). The standard of the intensive therapy included respiratory support, infusion therapy and sedation/muscle relaxation, and analgesia. We investigated the red blood cell flux by laser Doppler flowmetry (perfusion unit) – the device was placed on skin and antral gastric mucosa (LAKK 01, Russia); noninvasive hemodynamic monitoring with thoracic bioimpedansometry (Diamant M, Russia) and invasive by PiCCO+ in unstable patients (Pulsion, Germany). The characteristics of blood gas and oxygen consumption were evaluated by Bayer RapidLab (Bayer, Germany) and lactate/pyruvat concentration (Boeringer Mannheim, Germany). The dates were analyzed by t test, Fisher criteria. P < 0.05 was considered statistically significant.

Results

The serum lactate/pyruvate level was increased in both groups of patients on day 1 (m ± SD, 3.5 ± 1.2 vs 3.8 ± 1.0 mmol/l; nonsignificant). According to laser Doppler flowmetry the skin and the mucosa perfusion were decreased versus the control group (red blood cell flux 0.45 ± 0.12 in control vs 0.12 ± 0.03 in perfusion unit; significant). Group 1 was defined as a normalization of perfusion to day 2, whereas the disturbances of microcirculation remained in group 2 up to day 2. The microcirculatory index was not correlated with cardiac index (r = 0.26, nonsignificant). The extra lung water index by PiCCO+ was correlated with the microcirculatory index (r = 0.56, P < 0.05): group 1 associated with a normal index versus group 2 with increased extra lung water (13 ± 4 vs 23 ± 12; significant).

Conclusion

The recovery of the microcirculatory index (red blood cell flux) is associated with favorable outcome in severe trauma patients.