Goal-directed colloid versus crystalloid therapy and microcirculatory blood flow following ischemia/reperfusion.

Ischemia/reperfusion can impair microcirculatory blood flow. It remains unknown whether colloids are superior to crystalloids for restoration of microcirculatory blood flow during ischemia/reperfusion injury. We tested the hypothesis that goal-directed colloid – compared to crystalloid – therapy improves small intestinal, renal, and hepatic microcirculatory blood flow in pigs with ischemia/reperfusion injury. This was a randomized trial in 32 pigs. We induced ischemia/reperfusion by supra-celiac aortic-cross-clamping. Pigs were randomized to receive either goal-directed isooncotic hydroxyethyl-starch colloid or balanced isotonic crystalloid therapy. Microcirculatory blood flow was measured using Laser-Speckle-Contrast-Imaging. The primary outcome was small intestinal, renal, and hepatic microcirculatory blood flow 4.5 h after ischemia/reperfusion. Secondary outcomes included small intestinal, renal, and hepatic histopathological damage, macrohemodynamic and metabolic variables, as well as specific biomarkers of tissue injury, renal, and hepatic function and injury, and endothelial barrier function. Small intestinal microcirculatory blood flow was higher in pigs assigned to isooncotic hydroxyethyl-starch colloid therapy than in pigs assigned to balanced isotonic crystalloid therapy (768.7 (677.2–860.1) vs. 595.6 (496.3–694.8) arbitrary units, p =.007). There were no important differences in renal (509.7 (427.2–592.1) vs. 442.1 (361.2–523.0) arbitrary units, p =.286) and hepatic (604.7 (507.7–701.8) vs. 548.7 (444.0–653.3) arbitrary units, p =.376) microcirculatory blood flow between groups. Pigs assigned to colloid – compared to crystalloid – therapy also had less small intestinal, but not renal and hepatic, histopathological damage. Goal-directed isooncotic hydroxyethyl-starch colloid – compared to balanced isotonic crystalloid – therapy improved small intestinal, but not renal and hepatic, microcirculatory blood flow in pigs with ischemia/reperfusion injury. Whether colloid therapy improves small intestinal microcirculatory blood flow in patients with ischemia/reperfusion needs to be investigated in clinical trials. Legend to graphical abstract: Goal-directed colloid – compared to crystalloid – therapy improved small intestinal microcirculatory blood flow (Flux (a.u.)) in pigs with aortic-cross-clamping-induced ischemia/reperfusion injury. Whether colloid therapy improves small intestinal microcirculatory blood flow in patients with ischemia/reperfusion needs to be investigated in clinical trials. a.u. = arbitrary units, HES = hydroxyethyl-starch. Adapted and modified with permission from: Behem et al., Microvasc Res 2022, DOI: https://doi.org/10.1016/j.mvr.2022.104383. [Display omitted] • Colloids improved small intestinal microcirculatory blood flow in ischemia/reperfusion. • Colloids also led to less small intestinal histopathological damage. • There were no important differences of renal and hepatic microcirculatory blood flow. [ABSTRACT FROM AUTHOR]