Microcirculation and intravascular coagulopathy in patients with severe sepsis and septic shock

Introduction

Sidestream darkfield imaging (SDF) technology is a new method to visualize directly microcirculation. In this study we examined the perfusion of the oral mucosa in patients with severe sepsis and septic shock in order to evaluate the link between the severity of illness, microcirculation and intravascular coagulopathy.

Methods

Microcirculation was analysed in 46 ICU patients with clinical suspicion for sepsis and procalcitonin >2 ng/ml. Microcirculation was recorded daily over a 7-day period (d0 to d6). Each day, at least five single film clips were taken by SDF and analysed with special software on a PC. We used the functional vessel density and distribution of the vessel diameters as well-established parameters to qualify microcirculation. Laboratory parameters, hemodynamic data and vital signs were also registered. The degree of disseminated intravascular coagulopathy was evaluated by calculating the overt DIC score (according to ISTH), and severity of illness was determined using SAPS II and the SOFA score.

Results

During the stay in the ICU we observed a continuous descent of the DIC score (1.82 ± 1.91 on d0 vs 1.3 ± 1.94 on d6) as well as a decline of SAPS II (63.1 ± 14.1 on d0 vs 57.1 ± 18.4 on d6) and SOFA score (12.2 ± 3.9 on d0 vs 9.2 ± 5.8 on d6). The percentage of smallest vessels below 25 μm diameter decreased initially from 79.5 ± 21.9% (d1) to rise up then persistently 86.2 ± 10.3% (d6). Nonsurvivors (n = 11) had, compared with survivors (n = 35), a significantly higher initial DIC score on day 0 (1.3 ± 1.6 vs 2.05 ± 4.1; P < 0.05).

Conclusions

Our data show a clear relation between the time courses of DIC and microcirculation in patients with severe sepsis and septic shock. This finding is in line with previous reports stating the profound impact of DIC on microcirculation and finally on patient outcome.