Association between Doppler snuffbox resistive index and tissue perfusion in septic patients

Background: Doppler snuffbox resistive index (SBRI) can be a accurate parameter at the bedside to evaluate the status of peripheral vascular. We evaluated whether SBRI could relate to tissue hypoperfusion and could predict lactate clearance in septic patients. Methods: We conducted a prospective observational study in a tertiary general and teaching hospital in China.From July 2019 to Decemeber 2019,all consecutive adult patients with septic shock who required ICU admission were included. At the same time,postoperative patients were studied as a control group.we recorded the hemodynamic parameters including SBRI and PI which were measured simultaneously after involved . Results: We evaluated 44 patients with septic shock in study group and 20 stable postoperative patients in control group. Patients with septic shock had higher SOFA scores,PCT, CI and lactate than patients in control group.The SBRI was correlated with PI and lactate. The CI was not correlated with lactate in all patients.Based on Lactate clearance in first 6 hours, the septic shock patients were divided into the Lactate clearance ≥20% or the Lactate clearance <20% group.CI is no significal difference between two groups.SBRI of the Lactate clearance <20% group is higher than Lactate clearance≥20% group and control group.PI of the Lactate clearance <20% group is lower than Lactate clearance≥20% group and control group.The cutoff of the SBRI value was ≥1.09 for predicting 6h-lactate clearance after resuscitation, resulting in a sensitivity of 68.8% and a specificity of 85.7%. The cutoff of the PI value was ≤0.99 for predicting 6h-lactate clearance after resuscitation, resulting in a sensitivity of 64.3% and a specificity of 81.2%. The SBRI was significantly better than the PI for predicting 6h-lactate clearance after resuscitation. Conclusions: SBRI is correlated with tissue perfusion parameters in critical ill patients. Abnormal SBRI was better than PI in suggesting disorder of lactate clearance of septic patients. SBRI is a better indicator of abnormal tissue perfusion than CI. Further investigations are required to determine whether the correction of abnormal SBRI and PI may improve success rate of resuscitation of septic shock.