CXCL8 and hematoma: The data distributions examined recommended the use of parametric tests instead of non-parametric tests [25], and there was no statistically significant difference between venous blood and hematoma fluid concentration for cytokines IL-1β, IL-2, IL-12, IL-15 and IL-1RA, a significantly higher concentration in venous blood compared to hematoma fluid for TNF-α and a significantly higher concentration in hematoma fluid compared to venous blood for IL-7, IL-6, CCL2, CXCL9, IL-2R, CXCL10, IL-17, CXCL8, IL-5, IL-10 and IL-13.