Significantly increased low shear rate viscosity, blood elastic modulus, and RBC aggregation in adults following cardiac surgery

Abstract

Open heart surgeries are common for treating ischemic and heart valve disease. During cardiac surgery, cardiopulmonary bypass (CPB) can temporarily take over the function of heart and lungs. However, elevated red blood cell (RBC) aggregation may lead to the common side-effects such as microinfarction. We investigated blood physical properties changes and the correlation between blood microstructure, viscoelastic response and biochemical changes following surgery with CPB. We examined shear-rate dependent blood viscosity, elasticity and RBC aggregate size in the pre-surgery disease state, post-surgery state and long-term recovery state of cardiac surgical patients. Within a week following surgery, the patient hematocrit was significantly lower due to CPB. Despite lower RBC concentration, the RBC aggregate shape became larger and more rounded, which is correlated to the elevated plasma fibrinogen related to systemic inflammatory response. During the same period, the hematocrit-adjusted low shear rate viscosity increased significantly, as did the yield stress, indicating more solid-like behavior for blood. Six months to one year later, all the physical and biochemical properties measured returned to baseline.

Patient and haemodynamic factors affecting intraoperative graft flow during coronary artery bypass grafting: an observational pilot study

“…Coronary artery blood flow is not at steady-state, making its viscosity inconstant. Furthermore, previous studies have reported a significant increase in blood viscosity during and after cardiac surgery 33 . Cardiac surgery can cause abnormal blood rheological characteristics that may be associated with lung dysfunction and endothelial damage 34 .…”

“…Cardiac surgery can cause abnormal blood rheological characteristics that may be associated with lung dysfunction and endothelial damage 34 . In addition, blood viscosity changes due to systemic inflammatory and thrombotic responses during cardiac surgery 33 . Although blood viscosity was measured twice during surgery and was divided into systolic and diastolic viscosity in this study, it changes continuously according to the blood flow during surgery, making it difficult to determine the real-time relationship between viscosity and TTFM.…”

The Effect of Whole Blood Viscosity on Intraoperative Graft Flow during Coronary Artery Bypass Graft Surgery: An Observational Pilot Study

“…Coronary artery blood flow is not at steady-state, making its viscosity inconstant. Furthermore, previous studies have reported a significant increase in blood viscosity during cardiac surgery and after surgery [32]. Cardiac surgery can cause abnormal blood rheological characteristics that may be associated with lung dysfunction and endothelial damage [33].…”

“…Cardiac surgery can cause abnormal blood rheological characteristics that may be associated with lung dysfunction and endothelial damage [33]. In addition, blood viscosity changes due to systemic inflammatory and thrombotic responses during cardiac surgery [32]. Although the blood viscosity was measured twice during surgery and was divided into systolic and diastolic viscosity, blood viscosity changes according to the blood flow with continuous change during the surgery, making it difficult to determine the real-time relationship between viscosity and TTFM.…”

The Hemocompatibility of Nanoparticles: A Review of Cell–Nanoparticle Interactions and Hemostasis

“…There are three main factors that can influence blood viscosity, namely hematocrit, erythrocyte aggregation and erythrocyte deformation [22]. All three factors can be altered by NP–erythrocyte interactions, which underlines the importance of carefully studying the influence of NPs on the critical functions of blood cells.…”