Dextran-based Priming vs. Crystalloid and Mannitol-based Priming Solution in Adult Cardiac Surgery

A Randomized Controlled Trial Comparing Dextran-based Priming (PrimECC), and Standard Crystalloid and Mannitol-based Priming Solution in Adult Cardiac Surgery

This study will compare two priming solutions for extracorporeal circulation, one based on Dextran 40, one based on crystalloid and mannitol. Primary endpoint is oncotic pressure during cardiopulmonary bypass. Secondary endpoints included fluid balance and organ functions.

This is a prospective, single center, double-blinded, randomized controlled clinical trial. Eighty patients are randomized 1:1 to either cardiopulmonary bypass with the dextran-based solution or standard priming with Ringer-Acetate and Mannitol. Primary endpoint will be oncotic pressure during cardio pulmonary bypass. Secondary endpoints include perioperative fluid balance, coagulation, platelet function, postoperative bleeding volume, transfusion requirements, renal function, liver function, pulmonary function, inflammatory activation and markers for brain and heart injury. Blood samples for oncotic pressure measurements will be collected from an arterial line before and during surgery. Organ function will be assessed before surgery and 2 hours cardio pulmonary bypass.

The oncotic pressure of the PrimECC solution is higher than that of a crystalloid Ringer-acetate/mannitol solution. It should maintain the plasma oncotic pressure during and after cardiopulmonary bypass (CPB). Subsequently, the leakage of fluids from the systemic circulation to the interstitial compartment during CPB can be reduced, and a higher plasma volume and a better fluid balance can be achieved.

The oncotic pressure in plasma is measured using an Osmomat 050 and reported in kPa. Points of measurement is before ECC and at 60 minutes into ECC

Patient fluid balance is registered from ECC-start until 24 hours post-ECC. Infusion of crystalloids and colloids and urine output is registered in ml.

Bleeding is registered from ECC-start until 24 hours post-ECC. Intraoperative bleeding and postoperative chest tube drainage for 24 hours are added and registered in ml.

Transfusions of red blood cells, platelets and plasma from ECC-start until 24 hours post-ECC are registered and reported in ml.

Blood samples will be analyzed with modified rotational thromboelastometry (ROTEM) and calibrated automated thrombography. Points of measurement will be before ECC and at 2 hours post-ECC. Results will be reported as normal, above normal or below normal.

Blood samples will be analyzed calibrated automated thrombography. Points of measurement will be before ECC and at 2 hours post-ECC. Results will be reported as normal, above normal or below normal.

Platelet function will be measured with impedance aggregometry (Multiplate). Points of measurement will be before ECC and at 2 hours post-ECC. Results will be reported as normal or below normal.

Renal function is measured as µmol/L of Creatinine in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

Renal tubular damage is measured by analysis of U-NAG. Urine is collected before ECC and at 60 minutes into ECC. Results will be reported as U-NAG/U-Creatinine ratio (U/min).

The liver function is measured as µkat/L of ASAT in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

The liver function is measured as µkat/L of ALAT in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

The pulmonary function is measured by arterial blood gases assessing PaO2/FiO2 and reported in mmHg. Points of measurement will be before ECC and at 2 hours post-ECC.

The ischemic status of the heart is measures as ng/L of highly sensitive Troponin-T. Points of measurement will be before ECC and at 24 hours post-ECC.

Brain damage is measured as ng/L Tau in plasma. Points of measurement will be before ECC and at 2 hours post-ECC.

Brain damage is measured as ng/L of NFL in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

Brain damage is measured as µg/L of S100B in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

Brain damage is measured as µg/L of NSE in serum. Points of measurement will be before ECC and at 2 hours post-ECC.

Inflammatory activation is measured as ng/L of IL-6 in plasma. Points of measurement will be before ECC and at 2 hours post-ECC.

Inclusion Criteria: Age 50 - 75 years Elective cardiac surgery procedure with expected CBP time above 90 minutes Subject provides a legally effective informed consent. Exclusion Criteria: Known previous cardiac surgery Coagulation disorder Malignancy Kidney failure Liver failure Ongoing septicaemia Ongoing antithrombotic treatment other than acetylsalicylic acid Systemic inflammatory disorders treated with corticosteroids Not able to understand Swedish