Sepsis and sepsis-associated encephalopathy (SAE) are common intensive care unit (ICU) diseases; the morbidity and mortality are high. The present study analyzed the sensitivity of different diagnostic criteria of sepsis 1.0 and 3.0, epidemiological characteristics of sepsis and SAE, and explored its risk factors for death, short-term, and long-term prognosis. The retrospective study included patients in ICU from January 2015 to June 2016. After excluding 58 patients, 175 were assigned to either an SAE or a non-SAE group (patients with sepsis but no encephalopathy). The sensitivity of the diagnostic criteria was compared between sepsis 1.0 and 3.0, respectively. Between-group differences in baseline data, Acute Physiology and Chronic Health Evaluation II score (APACHE II score), Sequential Organ Failure Assessment score (SOFA score), etiological data, biochemical indicators, and 28-day and 180-day mortality rates were analyzed. Survival outcomes and long-term prognosis were observed, and risk factors for death were analyzed through 180-day follow-up. The sensitivity did not differ significantly between the diagnostic criteria of sepsis 1.0 and 3.0 (P = .286). The 42.3% incidence of SAE presented a significantly high APACHE II and SOFA scores as well as 28-day mortality and 180-day mortality (all P < .001). The incidence of death was 37.1%. The multivariate stepwise regression analysis demonstrated that the risk of death in SAE group was significantly higher than the non-SAE group (P < .001). Sepsis-associated encephalopathy is a risk factor for sepsis-related death (relative risk [RR] = 2.868; 95% confidence interval: 1.730-4.754; P < .001). Although males showed a significantly high rate of 28-day and 180-day mortality (P = .035 and .045), it was not an independent risk factor for sepsis-related death (P = .072). The long-term prognosis of patients with sepsis was poor with decreased quality of life. No significant difference was observed in prognosis between the SAE and non-SAE groups (P > .05). Both diagnostic criteria cause misdiagnosis, and the sensitivity did not differ significantly. The incidence of SAE was high, and 28-day and 180-day mortality rates were significantly higher than those without SAE. Sepsis-associated encephalopathy is a risk factor for poor outcome. The overall long-term prognosis of patients with sepsis was poor, and the quality of life decreased.

The pathogenesis of sepsis is complex. Mitochondrial dysfunction, which is responsible for energy metabolism, intrinsic apoptotic pathway, oxidative stress, and systemic inflammatory responses, is closely related with severe sepsis induced death. Mitochondria DNA (mtDNA) contain un-methylated cytosine phosphate guanine (CpG) motifs, which exhibit immune stimulatory capacities. The aim of this study was to investigate the role and mechanism of mtDNA release on lipopolysaccharide (LPS) induced acute lung injury (ALI) and systemic inflammation. Following LPS injection, plasma mtDNA copies peak at 8 h. Compared with wild-type (WT) mice, mtDNA in toll like receptor 4 knockout (TLR4 KO) mice were significantly decreased. MtDNA intra-peritoneal administration causes apparent ALI as demonstrated by increased lung injury score, bronchoalveolar lavage fluid (BALF) total protein and wet/dry (W/D) ratio; mtDNA injection also directly provokes systemic inflammation, as demonstrated by increased IL-1β, IL-6, high-mobility group protein B1 (HMGB1) level; while nuclear DNA (nDNA) could not induce apparent ALI and systemic inflammation. However, compared with WT mice, TLR4 KO could not protect from mtDNA induced ALI and systemic inflammation. Specific TLR9 inhibitor, ODN 2088 pretreatment can significantly attenuate mtDNA induced ALI and systemic inflammation, as demonstrated by improved lung injury score, decreased lung wet/dry ratio, BALF total protein concentration, and decreased systemic level of IL-1β, IL-6 and HMGB1. MtDNA administration activates the expression of p-P38 mitogen-activated protein kinases (MAPK) in lung tissue and specific TLR9 inhibitor pretreatment can attenuate this activation. Thus, LPS-induced mtDNA release occurs in a TLR4-dependent manner, and mtDNA causes acute lung injury and systemic inflammation in a TLR9-dependent and TLR4-independent manner.