Effect of intravascular cellular aggregate dissolution in postoperative patients

Area of Science:

• Physiology
• Surgical Medicine
• Biomedical Engineering

Background:

• Postoperative changes in blood viscosity and oxygen consumption are not fully understood in humans.
• Previous animal studies indicated a link between increased packed cell (PC) viscosity and decreased total body oxygen (O2) consumption after surgery.
• Intravascular cellular aggregates (ICA) are implicated in microcirculatory disturbances.

Purpose of the Study:

• To investigate if increased PC viscosity after elective surgery in humans correlates with reduced total body O2 consumption.
• To determine the impact of resolving ICA on PC viscosity and O2 consumption.
• To evaluate the efficacy of dextran-40 in reversing these postoperative changes.

Main Methods:

• Studied 39 patients undergoing elective surgery.
• Measured total body O2 consumption, PC viscosity, and whole blood (WB) viscosity at various postoperative time points.
• Administered saline and dextran-40 infusions to assess their effects on measured parameters.
• Monitored resolution of ICA following dextran-40 infusion.

Main Results:

• Total body O2 consumption was significantly reduced 6, 24, and 48 hours postoperatively.
• PC viscosity markedly increased 24 hours after surgery.
• Dextran-40 infusion normalized total body O2 consumption and PC viscosity by resolving ICA.
• Saline infusion had no significant effect on O2 consumption or PC viscosity.

Conclusions:

• Surgical trauma in humans leads to increased PC viscosity and microcirculatory impairment, evidenced by decreased total body O2 consumption.
• Resolution of ICA using dextran-40 effectively reverses these detrimental postoperative effects.
• Targeting ICA represents a potential therapeutic strategy for improving microcirculation after surgery.