A preliminary study on the classification and prognosis of microcirculation alterations in patients with septic shock

Abstract

Objective: To explore the correlation between different types of microcirculation alterations and the prognosis in patients with septic shock. Methods: This research employed a prospective observational study methodology for selecting subjects with septic shock. Side-stream dark field(SDF) was used to monitor the sublingual microcirculation to determine the total vascular density (TVD), perfused vessel density (PVD), the proportion of perfused vessels (PPV), and the microvascular flow index (MFI), heterogeneity index (HI) indicators. At the bedside, patients with microcirculation disorders were divided into four types: stasis, dilution, heterogeneity, and hyperdynamic. The 30-day survival status after enrollment and hemodynamics parameters were recorded. Results: A total of 64 patients with septic shock were selected in the study, including 18 cases of stasis type, 11 of dilution type, 18 of heterogeneous type, and 17 of hyperdynamic type. There were statistical differences in the mean arterial pressure (MAP) [stasis:(77±9) mmHg (1 mmHg=0.133 kPa), dilution:(80±11) mmHg, heterogeneity: (78±12) mmHg, hyperdynamic:(88±12) mmHg], TVD [ stasis:(10.84±3.01) mm/mm2, dilution:(9.64±1.72) mm/mm2, heterogeneity:(11.39±2.18) mm/mm2, hyperdynamic: (11.87±2.67) mm/mm2 ], PVD [stasis:(5.93±1.94) mm/mm2, dilution:(6.86±1.48) mm/mm2, heterogeneity: (8.31±1.78) mm/mm2, hyperdynamic:(9.68±2.46) mm/mm2], PPV [stasis:52.45 (46.25, 63.33)%, dilution:73.70 (61.50, 75.20)%, heterogeneity: 71.25 (67.95, 77.00)%, hyperdynamic:80.70 (77.25, 86.45)%], MFI(stasis:1.34±0.45, dilution: 1.70±0.38, heterogeneity:1.82±0.28, hyperdynamic:2.25±0.33), and HI [stasis:0.68 (0.51, 1.87), dilution: 0.57 (0.49, 0.64), heterogeneity:0.70 (0.59, 0.91), hyperdynamic: 0.40 (0.37, 0.52)] of the four types of microcirculation alterations. The cumulative survival rates in stasis, dilution, heterogeneity and hyperdynamic types at 30 day were 7/18, 4/11, 10/18 and 14/17, respectively, which in stasis and dilution types was significantly lower than that of hyperdynamic type (χ²=7.221, P=0.007;χ2=6.764, P=0.009). Multivariate Cox regression analysis showed the type of microcirculation alterations (stasis:RR=4.551, 95%CI 1.228-16.864, P=0.023; dilution:RR=4.086, 95%CI 1.011-16.503, P=0.048), acute physiology and chronic health evaluation Ⅱ (RR=1.077, 95%CI 1.006-1.153, P=0.032) were independent prognostic risk factors. Conclusions: Microcirculation alterations are common in patients with septic shock, and it is hard to predict the types of microcirculation alterations with hemodynamics parameters. The prognosis of patients with septic shock is related to the types of microcirculation alterations, suggesting that routine monitoring of microcirculation might be helpful to guide hemodynamic therapy.