Influence of colloid infusion on coagulation during off-pump coronary artery bypass grafting

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Hematology

Background:

• Colloid infusions are frequently used for volume replacement in cardiac surgery.
• The impact of different colloid types on coagulation during off-pump coronary artery bypass grafting (OP-CABG) requires further investigation.
• Maintaining hemostasis is critical for minimizing complications and improving outcomes in OP-CABG patients.

Purpose of the Study:

• To evaluate the influence of medium molecular weight hydroxyethyl starch (MMW-HES 200/0.5), low molecular weight hydroxyethyl starch (LMW-HES 130/0.4), and gelatin on coagulation parameters in patients undergoing OP-CABG.
• To compare the efficacy of these colloids in preserving coagulation function and minimizing blood loss.

Main Methods:

• A prospective randomized trial involving 30 patients undergoing elective OP-CABG.
• Patients were assigned to receive MMW-HES 200/0.5 (Group I), LMW-HES 130/0.4 (Group II), or gelatin (Group III).
• Coagulation parameters including hemoglobin, activated coagulation time (ACT), prothrombin time (PT), activated partial thromboplastin time (aPPT), platelet count, fibrinogen, and von Willebrand factor (vWF) were assessed at specified intervals.
• Postoperative chest tube drainage was also measured.

Main Results:

• All groups showed a significant decrease in hemoglobin, platelet count, and fibrinogen, but not to a degree requiring blood transfusion.
• Group I (MMW-HES 200/0.5) exhibited a significant decrease in vWF to 67% from baseline, compared to 85% in Group II and 79% in Group III.
• vWF levels remained below baseline for 24 hours in Group I, while increasing above baseline by 6 hours postoperatively in Groups II and III.
• Postoperative chest tube drainage was significantly higher in Group I (856 ± 131 ml) compared to Group II (550 ± 124 ml) and Group III (582 ± 159 ml).

Conclusions:

• Low molecular weight hydroxyethyl starch (LMW-HES 130/0.4) demonstrates superiority over medium molecular weight hydroxyethyl starch (MMW-HES 200/0.5) and gelatin in patients undergoing OP-CABG.
• LMW-HES 130/0.4 provides better preservation of coagulation function.
• The enhanced volume effect associated with LMW-HES 130/0.4 contributes to improved perioperative hemostasis.