From macrohemodynamic to the microcirculation

Hemodynamic monitoring allows clinicians to manage macrocirculation.
In a prospective, randomized, controlled trial, on surgical abdominal patients, protocol group managed to keep O₂ER < 27%, versus control group with "standard" therapy, had fewer organ failures and lower length of hospital stay.
Vasoconstrictive and positive inotropic effects of methylene blue during septic shock, wasn’t associated with hemodynamic or respiratory changes.
However just monitoring macrocirculation appeared to be not enough to improve patient outcome and splanchnic perfusion was monitored with tonometer. In 12 abdominal surgical patients, intraoperative splanchnic ischemia, was documented by gastric intramucosal pH-i, and directly correlated to IL-6 plasma levels increase of and to postoperative complications. PHi and ΔCO₂ were sensitive prognostic indices during abdominal aortic aneurysm surgery in 29 patients.
Recently NIRS and SDF techniques were introduced to monitor microcirculation.
In septic patients treatment with activated protein C (rh-aPC) improved StO₂ baseline and reperfusion and increased tissue metabolism. Moreover rh-aPC treatment improves sublingual microcirculation in 13 patients with severe sepsis compared to 9 patients.
Levosimendan compared to dobutamine in a double-blind clinical trial improved sublingual microcirculatory blood flow in patients with septic shock.
A prospective randomized trial, on 20 septic patients, suggests more favorable effect on microcirculation of leukodepleted RBC transfusions compared with non-leukodepleted ones. In a secondary analysis old RBC transfusion was associated with plasmatic fHb increase and decreased microvascular density.
In conclusion monitoring microcirculation help physician to treat patients. We can observe in vivo physiopathological alterations and study the effects of therapies aiming to fix these alterations.