Does Modified Ultrafiltration Improves Inflammatory Response and Cardiopulmonary Function After CABG Procedures?

Patient selection After Institutional Review Board approval, a prospective study was carried out with 60 consecutive patients underwent CABG cardiopulmonary bypass (CPB) in our institution. All patients signed a consent form before enrolled into the study. The patients were randomly assigned to a control group treated with no modified ultrafiltration (CO group) or to a treatment group with modified ultrafiltration (MUF group) after bypass period. The inclusion criteria were: patients aged from 30 to 70 years old, both genders, left ventricle ejection fraction higher than 39%, normal renal function, with or without diabetes, and who underwent CABG with no associate procedures. The exclusion criteria were: left ventricle ejection fraction lower than 39% and abnormal renal function (serum creatinine > 2.0 mg/dl, clearance lower than 45 mL/m in males or lower than 40 mL/m in females).

Surgical procedure:

After anesthesia induction, the patients were monitored using a continuous cardiac output catheter (Edwards Lifesciense, Irvine. USA), invasive arterial mean pressure catheter, and urine output catheter.

All patients were submitted to tepid bypass (32 o C) with a target flow of 2.4 L/min/m2. After CPB was established the aorta was cross clamped and the distal anastomoses were performed. The blood tepid cardioplegia were used during the cross clamp period. The clamp was released and a C-clamp was applied for the proximal anastomosis effectuation. After a proximal anastomosis complementation, the patients were weaned from the bypass. Following the CPB period the patients were randomly assigned to MUF group or CO group. All operations were performed by one surgeon (O.P.).

Modified Ultrafiltration. The ultrafiltration was performed in heparinized patients between the arterial and the venous tubings of the CPB circuit, using a H-500 filter (polyestersuphone) with an effective membrane area of 0.5 m2, pore size of 5 nm, prime volume of 34 ml, maximum transmembrane pressure of 400 mmHg, internal fiber diameter of 200 µm, and fiber thickness wall of 30 µm (Braile Biomedica, São José do Rio Preto, Brazil).