Role of arterial blood glucose and interstitial fluid glucose difference in evaluating microcirculation and clinical prognosis of patients with septic shock: a prospective observational study

Background Microcirculation abnormality in septic shock is closely associated with organ dysfunction and mortality rate. It was hypothesized that the arterial blood glucose and interstitial fluid (ISF) glucose difference (G(A-I)) as a marker for assessing the microcirculation status can effectively evaluate the severity of microcirculation disturbance in patients with septic shock. Methods The present observational study enrolled patients with septic shock admitted to and treated in the intensive care unit (ICU) of a tertiary teaching hospital. The parameters reflecting organ and tissue perfusion, including lactic acid (Lac), skin mottling score, capillary refill time (CRT), venous-to-arterial carbon dioxide difference (Pv-aCO(2)), urine volume, central venous oxygen saturation (ScvO(2)) and G(A-I) of each enrolled patient were recorded at the time of enrollment (H0), H2, H4, H6, and H8. With ICU mortality as the primary outcome measure, the ICU mortality rate at any G(A-I) interval was analyzed. Results A total of 43 septic shock patients were included, with median sequential organ failure assessment (SOFA) scores of 10.5 (6-16), and median Acute Physiology and Chronic Health Evaluation (APACHAE) II scores of 25.7 (9-40), of whom 18 died during ICU stay. The G(A-I) levels were negative correlation with CRT (r = 0.369, P < 0.001), Lac (r = -0.269, P < 0.001), skin mottling score (r=-0.223, P < 0.001), and were positively associated with urine volume (r = 0.135, P < 0.05). The ICU mortality rate of patients with septic shock presenting G(A-I) <= 0.30 mmol/L and >= 2.14 mmol/L was significantly higher than that of patients with G(A-I) at 0.30-2.14 mmol/L [65.2% vs. 15.0%, odds ratio (OR) = 10.625, 95% confidence interval (CI): 2.355-47.503]. Conclusion G(A-I) was correlated with microcirculation parameters, and with differences in survival. Future studies are needed to further explore the potential impact of G(A-I) on microcirculation and clinical prognosis of septic shock, and the bedside monitoring of G(A-I) may be beneficial for clinicians to identify high-risk patients.