The use of data science to analyse physiology of oxygen delivery in the extracorporeal circulation

Abstract

BackgroundRecent scientific reports have brought into light a new concept of goal-directed perfusion (GDP) that aims to recreate physiological conditions in which the risk of end-organ malperfusion is minimalized. The aim of our study was to analyse patients’ interim physiology while on cardiopulmonary bypass based on the haemodynamic and tissue oxygen delivery measurements. We also aimed to create a universal formula that may help in further implementation of the GDP concept.MethodsWe retrospectively analysed patients operated on at the Wroclaw University Hospital between June 2017 and December 2018. Since our observations provided an extensive amount of data, including the patients’ demographics, surgery details and the perfusion-related data, the Data Science methodology was applied.ResultsA total of 272 (mean age 62.5 ± 12.4, 74% male) cardiac surgery patients were included in the study. To study the relationship between haemodynamic and tissue oxygen parameters, the data for three different values of DO2i (280 ml/min/m2, 330 ml/min/m2 and 380 ml/min/m2), were evaluated. Each set of those lines showed a descending function of CI in Hb concentration for the set DO2i.ConclusionsModern calculation tools make it possible to create a common data platform from a very large database. Using that methodology we created models of haemodynamic compounds describing tissue oxygen delivery. The obtained unique patterns may both allow the adaptation of the flow in relation to the patient’s unique morphology that changes in time and contribute to wider and safer implementation of perfusion strategy which has been tailored to every patient’s individual needs.

Dilemmas of Adopting Goal-Directed Perfusion in Extracorporeal Circulation: A Narrative Review

“…Figure 1 shows the measurements taken at 10 s intervals to determine DO 2 in relation to hemoglobin level and cardiac index during 270 ECC procedures. 7 Each point on the graph is described by 3 parameters: DO 2 , hemoglobin level, and pump flow. These inseparable parameters occupy the entire graph, even in the areas of nonphysiological low DO 2 , because there are expected decreases in all ECC procedures, as previously mentioned.…”

“…Image reprinted with no modifications from Lukaszewski et al, “The use of data science to analyse physiology of oxygen delivery in the extracorporeal circulation,” BMC Cardiovasc Disord , 2019, under the terms of the CC BY 4.0 license. 7…”

“…As a result, the pump flow rate is often not adapted to the actual hemodynamic conditions, and vasoconstrictors are overused to increase blood pressure. 1,2,6,7 In recent years, a concept of perfusion management during ECC, goal-directed perfusion (GDP), has emerged to create optimal conditions for oxygen delivery (DO 2 ) and extraction, initiated by Rannuci et al 8 Based on his observations of renal function and DO 2 during ECC, the model of adequate tissue perfusion and optimal DO 2 during ECC is proposed. There are many doubts as to whether the new GDP methodology is based on a solid foundation for understanding and restoring human physiology in the newly created hemodynamic system, the patient-heart-lung machine model.…”

“…These inseparable parameters occupy the entire graph, even in the areas of nonphysiological low DO 2 , because there are expected decreases in all ECC procedures, as previously mentioned. 7 These decreases are mainly due to the reduction in pump flow, as other factors such as hemoglobin level, saturation, and oxygen content are usually kept constant during ECC.…”

“…As a result, the pump flow rate is often not adapted to the actual hemodynamic conditions, and vasoconstrictors are overused to increase blood pressure. 1,2,6,7…”