CARDIOPULMONARY MONITORING: Edited by Jan BakkerAutomated quantification of tissue red blood cell perfusion as a new resuscitation targetHilty, Matthias P.a,b; Ince, CanbAuthor Information aInstitute of Intensive Care Medicine, University Hospital of Zurich, Zurich, Switzerland bDepartment of Intensive Care, Erasmus MC, University Medical Center, Rotterdam, The Netherlands Correspondence to Dr Matthias P. Hilty, Institute of Intensive Care Medicine, University Hospital of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland. Tel: +41 44 255 1111; e-mail: [email protected] Current Opinion in Critical Care: June 2020 - Volume 26 - Issue 3 - p 273-280 doi: 10.1097/MCC.0000000000000725 Buy Metrics Abstract Purpose of review Identification of insufficient tissue perfusion is fundamental to recognizing circulatory shock in critically ill patients, and the primary target to restore adequate oxygen delivery. However, the concept of tissue perfusion remains ill-defined and out-of-reach for clinicians as point-of-care resuscitation target. Even though handheld vital microscopy (HVM) provides the technical prerequisites to collect information on tissue perfusion in the sublingual microcirculation, challenges in image analysis prevent quantification of tissue perfusion and manual analysis steps prohibit point-of-care application. The present review aims to discuss recent advances in algorithm-based HVM analysis and the physiological basis of tissue perfusion-based resuscitation parameters. Recent findings Advanced computer vision algorithm such as MicroTools independently quantify microcirculatory diffusion and convection capacity by HVM and provide direct insight into tissue perfusion, leading to our formulation a functional parameter, tissue red blood cell (RBC) perfusion (tRBCp). Its definition is discussed in terms of the physiology of oxygen transport to the tissue and its expected effect as a point-of-care resuscitation target. Further refinements to microcirculatory monitoring include multiwavelength HVM techniques and maximal recruitable microcirculatory diffusion and convection capacity. Summary tRBCp as measured using algorithm-based HVM analysis with an automated software called MicroTools, represents a promising candidate to assess microcirculatory delivery of oxygen for microcirculation-based resuscitation in critically ill patients at the point-of-care. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.