Introduction: Systematic vascular resistance evaluation parameters are mainly obtained through invasive monitoring. The evaluation of snuffbox artery resistance index (RI) is proven to predict lactate clearance in septic shock patients better than perfusion index. However, the normal ranges of snuff box RI and pulsatility index (PI) are still controversial. This study investigates the normal snuff box RI and PI ranges in volunteers.
Methods: Healthy volunteers and ICU patients were included. Volunteers were grouped by hypertension history and age, patients by shock status. Demographics, vital signs, and snuffbox artery parameters were collected. Categorical variables were presented as counts and percentages and compared using the chi-square test or Fisher's exact test. Continuous variables were presented as the median and interquartile range (IQR). When the data were normally distributed, the t-test or analysis of variance was used for comparison between groups; otherwise, the Mann - Whitney test was used. A p< 0.05 was considered statistically significant. Statistical analyses were performed using SPSS 27.0 and GraphPad Prism 10.0.0 software.
Results: 91 volunteers (avg. age 37) and 55 patients (avg. age 55) were enrolled. RI, and EDV showed significant differences between patients and different category volunteers, while PSV and PI did not. And EDV is statistically related to the 28-day mortality in patients group. Among volunteers, EDV differed significantly before and after exercise, with no PI or RI differences. Hypertension and age had no effect on snuffbox artery ultrasonic vascular tension parameters in volunteers, showing no statistical differences in ultrasonic vascular tension assessment related to these factors.
Conclusions: The study identified differences in the snuffbox artery between patients and healthy volunteers, determined normal RI and PI ranges as 0.72 to 0.75 and 1.93 to 2.03, and found trends in blood flow pre- and post-exercise. Diastolic flow changes may indicate early peripheral tone changes, providing a basis for future research.
