Evaluation of microcirculatory changes after bundle therapy and prognostic value by the ratio of transcutaneous oxygen pressure and transcutaneous carbon dioxide pressure in the treatment of septic shock / 中华危重病急救医学

ABSTRACT

Objective To evaluate microcirculatory changes after bundle therapy and prognostic values of the ratio of transcutaneous oxygen pressure and transcutaneous carbon dioxide pressure (PtcO2/PtcCO2) in the treatment of septic shock. Methods A retrospective analysis was conducted. Patients with septic shock admitted to department of intensive care unit (ICU) of Northern Jiangsu People's Hospital from July 2017 to February 2019 were enrolled. The gender, age, infection site, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ), the length of ICU stay and 28-day prognosis were collected; PtcCO2, PtcO2, PtcO2/PtcCO2 ratio, arterial lactate (Lac), central venous oxygen saturation (ScvO2), mean arterial pressure (MAP) were measured before treatment (at admission) and 6 hours after bundle treatment. According to the 28-day prognosis, the patients were divided into survival group and death group, and the differences of each index between the two groups were compared. The risk factors of prognosis were analyzed by binaryLogistic regression analysis. The receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of the related indicators for the 28-day mortality of septic shock patients. Results A total of 78 patients with septic shock were enrolled, with 47 cases in survival group and 31 cases in death group. Compared with survival group, APACHEⅡ score and PtcCO2 were higher and PtcO2/PtcCO2 ratio was lower in death group [APACHEⅡ28.33±6.35 vs. 21.61±6.64, PtcCO2 (mmHg, 1 mmHg = 0.133 kPa) 51.80±19.05 vs. 38.17±6.79, PtcO2/PtcCO2 ratio 1.20±0.72 vs. 1.80±0.81, all P < 0.05]. Compared with before treatment, the PtcO2/PtcCO2 ratio, Lac, MAP were substantially improved at 6 hours of bundle therapy [PtcO2/PtcCO2 ratio 1.76±0.81 vs. 1.56±0.82, Lac (mmol/L)3.74±2.40 vs. 4.42±2.60, MAP (mmHg) 83.34±7.58 vs. 71.00±5.36, all P < 0.05], and there was no changes in PtcCO2 and ScvO2. The PtcO2/PtcCO2 ratio at 6 hours of bundle therapy in the survival group was significantly higher than before treatment and was higher than that in death group (2.13±0.75 vs. 1.80±0.81, 1.19±0.53, both P < 0.05). There was no significant difference in PtcO2/PtcCO2 ratio of death group before and after treatment (1.19±0.53 vs. 1.20±0.72, P > 0.05). The binary Logistic regression showed that PtcO2/PtcCO2 ratio at 6 hours of bundle therapy and APACHEⅡ score were risk factors of prognosis [PtcO2/PtcCO2 ratio odds ratio (OR) = 7.876, P = 0.026; APACHEⅡscore OR = 0.846, P = 0.035]. ROC curve analysis showed that 6-hour of PtcO2/PtcCO2 ratio, APACHEⅡscore and 6-hour Lac level could predict 28-day mortality in septic shock patients, and the area under curve (AUC) was 0.864, 0.784, and 0.752 respectively. The cut-off value of 6-hour PtcO2/PtcCO2 ratio for predicting mortality in septic shock patients was 1.42, the sensitivity was 87.0％, and the specificity was 73.3％. In addition, the patients were divided into two groups according to whether the 6-hour PtcO2/PtcCO2 ratio was greater than 1.42. The results showed that compared with the PtcO2/PtcCO2 < 1.42 group, the APACHEⅡ score in PtcO2/PtcCO2 ≥ 1.42 group was lower, the 6-hour Lac level was lower, 24-hour Lac reaching standard rate was higher and the 28-day mortality was lower. Conclusions Compared with the traditional metabolic parameters, the improvement of early microcirculatory perfusion in patients with septic shock can reflect the effect of bundle therapy. The PtcO2/PtcCO2 ratio at 6 hours of bundle therapy can be used as a new index to predict the prognosis of patients with septic shock which supports the monitoring and evaluation of microcirculation in the early stage of treatment in septic shock.