[Changes in the colloid-osmotic pressure by a foreign colloid (dextran 70)]

Area of Science:

• Biochemistry
• Physiology
• Surgical Medicine

Background:

• Colloid osmotic pressure (COP) is crucial for fluid balance.
• Elective surgery can impact serum protein levels and COP.
• Dextran 70 is a plasma volume expander used perioperatively.

Purpose of the Study:

• To investigate the effect of Dextran 70 on serum colloid osmotic pressure (COP) post-surgery.
• To compare measured COP with calculated COP in patients receiving Dextran 70 versus a control group.
• To assess the duration of Dextran 70's influence on serum protein dynamics.

Main Methods:

• Serum COP was measured using a transducer with an artificial membrane (M=10000) in 55 surgical patients.
• Serum total protein, albumin, and globulin concentrations were determined to calculate COP.
• Patients were divided into Dextran 70 and control groups, with follow-up until the sixth postoperative day.

Main Results:

• No significant difference was observed in measured COP between the Dextran 70 and control groups.
• Measured COP reached its lowest point on the first postoperative day, not falling below 20 mm Hg.
• Calculated COP was significantly lower than measured COP in the Dextran 70 group for up to six days, unlike the control group.
• Serum protein levels decreased more in the Dextran 70 group after infusions.

Conclusions:

• Dextran 70 administration affects serum protein concentrations and influences COP calculations, despite not altering measured COP.
• The artificial membrane detected Dextran 70's effects on COP for up to six days post-administration.
• Potential mechanisms include increased intravascular volume, enhanced capillary permeability, or reduced albumin synthesis.