Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Donati A, Romanelli M, Romagnoli L, Botticelli L, Anastasi C, Pelaia P. Int Care Med. 2008;34(Supp 1):S104. Abstract 0395.
Introduction: In sepsis the link between the systemic inflammatory response and the development of MOF is represented by Microcirculatory and Mitochondrial Distress Syndrome (MMDS) that causes an important cellular impairment of aerobic methabolism not corrigible exclusively with a restoration of a normal hemodynamics and oxygen delivery. We observed the changes caused by MMDS in the tissue oxygenation and in the microcirculation with NIRS and microcirculatory analysis in patient with severe sepsis or septic shock, before, during and after Activated Protein C (APC) infusion. We evaluated if APC influences tissue saturation (an index of O2ER) and if alterations of hemodynamics are linked to these changes.
Methods: Prospective observational study. We evaluated ten septic patients treated with APC from December 2005 to September 2007. Microcirculation images were registered and analyzed by the SDF technic and MAS software that calculate the MFI (Microvascular Flow Index), mean velocity and FCD (Functional Capillary Density) parameters. We carried out evaluation with NIRS of the StO2 with the spectrometer InSpectra (Hutchinson Technology Inc., Minn) putting a probe of 15mm in the brachioradialis muscle of the patients. The measurements were made in 5 steps: pre-APC, at 24h, 48h, 72h and 24h after the end of the infusion (post-APC). Each measurement (of the basic StO2 and of the slope during and after the ischemia) was registered and transformed from the software InSpectra Analysis. The parameters analyzed with the non-parametric test of Wilcoxon for repeated measurement (P<0.05).
Results: MICROCIRCULATION: There was a significant increase of MFI and of FCD started after 72 h from the beginning of infusion for small and medium vessels (P<0.001) and an increase of mean velocity at 72h for small vessels and in post-APC for small and medium vessels (P<0.05)
NIRS: The increase of the basal StO2 during and after APC treatment and its decrease during the arterial occlusion are statistically significant (P<0.05). The increase of the StO2 slope after arterial occlusion is statistically significant starting from the second day of infusion of APC (P<0.05).
Conclusion: Microcirculation analysis throw SDF technic let visualize the significant modifications which begin in septic syndrome (low capillary density, reduced flow velocity, heterogeneity of the microcirculation) and also the improvements of the microcirculatory state during the APC infusion. There is an improvement of all the NIRS parameters after the APC infusion, which means an increase of tissutal O2ER. We have to verify if that increase is linked either with a reduced shunt effect in the microcirculation or with the end of metabolic down-regulation that involves the mitochondrial system. APC seams improve microcirculatory state in septic patients acting most of all on small vessels vases. NIRS and the microcirculation monitoring are useful tools to evaluate therapy and the outcome of severe sepsis and septic shock.
Reference(s): De Baker et al. Am J Respir Crit Care Med 2002; 166: 98–104 Boerma et al. Crit Care 2005; 9: 601–60. - Bernard et al. N Engl J Med 2001; 344: 699–709 - Ince C. Critical Care 2005; 9(Suppl 4): S13–19.