Microcirculation measurements: Barriers for use in clinical routine

In patients with shock, inflammation and sepsis alterations in microcirculation are common problems. Although the pathophysiologic consequences are well understood, measurements of microcirculation have not entered clinical routine so far.

To characterize the requirements for clinical microcirculation measurement techniques and the barriers for implementation into routine practice.

Clinical review of reliability, reproducibility, validity, availability and usefulness of clinically available measurement techniques to be used in patients with sepsis or cardiac surgery with cardiopulmonary bypass.

Few methods such as video microscopy are readily available at the bedside, but are hampered by the high variability of measurements and the lack of reliable automated software analysis. The correlation of microcirculation impairment measured by in-vivo microscopy with fatal outcomes has been established, but no recommendations have been given which parameters should be targeted to improve outcomes. Measurement of regional brain tissue oxygenation has been recommended for cardiac surgery, but does not specifically target microcirculation.

International guidelines for the management of sepsis or cardiac anesthesia do not recommend specific goals targeting the microcirculation directly, but global hemodynamics. The reason for this may be attributed to the lack of methods that fulfill the requirements necessary to be clinically acceptable. Once the validity, i.e. any improvement in patient's outcomes attributable to microcirculation measurements, can be established, clinical measurement of microcirculation could become part of routine treatment of patients with sepsis, inflammation and shock. Until then, more clinical studies targeting microcirculation are urgently needed.