Traditional hemorrhagic shock (HS) assessment methods focus solely on macrocirculatory indicators, failing to detect microcirculatory disturbances at an early stage, which may lead to misjudgment of disease severity or delayed intervention. This randomized controlled animal experimental study aims to construct a novel three-level quantitative assessment integrating basic vital signs, blood gas indicators, and microcirculatory parameters, to determine its accuracy and reliability in distinguishing mild, moderate, and severe HS, thereby providing a scientific tool for early precise staging and targeted resuscitation in clinical practice.

Following the quality control principles of experimental research (randomization, blinded assessment), 20 experts with associate senior professional titles or above in the fields of anesthesiology, critical care medicine, field surgery and other relevant disciplines were selected to conduct 3 rounds of anonymous Delphi consultations. Shock evaluation indicators were screened and their weights were determined by calculating the expert positive coefficient, opinion concentration degree and opinion coordination degree. A three-level assessment system consisting of basic vital signs, blood gas indicators and microcirculatory parameters was constructed, and quantitative scoring standards were formulated. A total of 64 SPF-grade SD rats (12 weeks old) were randomly divided into 4 groups (n=16): a sham operation group and mild, moderate, and severe HS groups (with blood loss accounting for 20%, 35% and 50% of total blood volume, respectively). Side stream dark-field (SDF) microcirculation imaging was employed to detect microcirculatory indicators, and mean arterial pressure (MAP) and oxygen saturation were recorded simultaneously to validate the accuracy of the assessment method.

The positive coefficients (100.0%, 100.0%, 88.9%) and coordination coefficients (Kendall's W increased from 0.144 to 0.444, P<0.05) of the 3 rounds of expert consultations were relatively high, with a coefficient of variation ranging from 0.07 to 0.27, indicating a significant improvement in the consistency of expert opinions. Finally, 5 core secondary indicators were identified, with their weights as follows: perfused vessel density (0.138 8), MAP (0.131 8), oxygen saturation (0.129 9), microvascular flow index (0.128 1) and perfused vessel proportion (0.126 3). The quantitative scoring standard showed that 5 to 10 points indicated mild HS, 11 to 15 points moderate, and 16-20 points severe. In animal experimental validation, the accuracy of this method in distinguishing mild, moderate and severe HS was 93.75% (95%CI: 71.7% to 98.9%), 93.75% (95%CI: 71.7% to 98.9%) and 100% (95%CI: 83.8% to 100%), respectively.

Our novel quantitative HS assessment tool based on SDF technology and Delphi method, can accurately distinguish HS of different severity levels (accuracy rate >90%), effectively integrate the monitoring dimensions of macrocirculation, oxygenation, and microcirculation. Our tool addresses the limitation of traditional assessment tools in neglecting microcirculation, providing reliable assessment for early precise identification, dynamic monitoring of disease progression, and targeted resuscitation of HS, with significant potential for clinical translation.