Relationship between Oxygen Extraction Ratio and Prognosis in Septic Shock Patients During Early Resuscitation

  Objective  To investigate the relationship between Oxygen extraction ratio(ERO₂) and prognosis of septic shock patients in the early stage of resuscitation.

  Methods  The data of the patients with septic shock admitted to the department of Critical Care Medicine of Peking Union Medical College Hospital from January 2016 to July 2021 were retrospectively collected. The patients were divided into the survival group and the death group according to the prognosis of the ICU. The baseline data, and Oxygen metabolism indexes including Oxygen delivery (DO₂), Oxygen consumption(VO₂), ERO₂ and lactate(Lac) of the two groups were collected. Risk factors for ICU death in patients with septic shock were analyzed using multifactorial Logistic regression, and the predictive value of each indicator for ICU death in patients with septic shock was assessed using receiver operating characteristic (ROC) curves.

  Results  A total of 73 patients with septic shock who met the inclusion and exclusion criteria were enrolled, including 21 cases in the death group and 52 cases in the survival group. The differences in acute physiology and chronic health evaluationⅡ(APACHEⅡ) scores and sequential organ failure assessment (SOFA) scores between the two groups were statistically significant (all P < 0.05). Compared with the survival group, 6 h after resuscitation in the death group, Lac 5.6(4.2, 10.0)mmol/L vs. 3.4(2.1, 6.9)mmol/L, P=0.009, VO₂(165±95) mL/(min·m²) vs. (106±58)mL/(min·m²), P=0.012, ERO₂(56.56±19.48)% vs.(33.71±13.24)%, P=0.000 were elevated, and there was no significant difference in DO₂ between the two groups266 (214, 384) mL/(min·m²) vs. 300 (250, 396)mL/(min·m²), P=0.159. The results of multifactorial Logistic regression analysis showed that ERO₂ was an independent risk factor for ICU death in patients with septic shock (OR=1.126, 95% CI: 1.053-1.203, P=0.000). The ROC curve showed that the area under the curve (AUC) of ERO₂ for predicting ICU death in septic shock patients was 0.833, with an optimal threshold of 45.93%, sensitivity of 76.19%, specificity of 94.23%, and its predictive efficacy was superior to that of the APACHEⅡ scores(AUC: 0.704), SOFA score(AUC: 0.778), and Lac(AUC: 0.668).

  Conclusion  ERO₂ in the early stage of septic shock resuscitation is an independent risk factor for ICU prognosis, which has a good predictive value for the prognosis of septic shock.