Moderate and extreme haemodilution in open-heart surgery: evaluation of haemolysis, cell damage and protein changes

[Effectiveness of the Cell Saver and salvage from ultrafiltered extracorporeal circulation in heart surgery]

The efficiency of two intraoperative techniques of blood saving were compared prospectively. During a period of eight months, in 120 adults patients undergoing heart surgery with a cardiopulmonary bypass (CPB). They all had blood removed before the start of CPB for isovolaemic haemodilution. They were randomly assigned to two groups (n = 60 for each): for group A patients, blood was salvaged during surgery before the start of the CPB, during cardioplegia, and from the CPB circuit at the end of surgery, using a Cell Saver 1V (Haemonetics), and returned to the patient in theatre or in intensive care; in group B patients, blood in the CPB circuit at the end of surgery was ultrafiltered and returned to the patient at the same time as 0.8 mg.kg-1 protamine sulfate. The same anaesthetic protocol was used in all the patients (flunitrazepam, phenoperidine and pancuronium bromide). There was no significant difference between the two groups in the volume of blood removed at the start of surgery (9.12 +/- 2.01 ml.kg-1 (A) vs. 8.85.2.22 ml.kg-1 (B)), in the amounts of replacement fluid (Haemaccel, 4% albumin) given to maintain volaemia, and in postoperative blood loss Red cell count, haemoglobin level and haematocrit were higher in the Cell Saver group at the third postoperative hour and on the first postoperative day, whereas fibrinogen levels and platelet count were higher in the ultrafiltration group at the same times. A mean of 1.02 +/- 1.71 homologous blood units were given to group A and 1.45 +/- 1.71 in group B (not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of Haemonetics Cell Saver for autotransfusion in cardiovascular surgery

The Haemonetics Cell Saver was evaluated as a tool for the refining of blood shed during cardiovascular surgery. After blood filtration the red cells are concentrated, washed and re-infused as red cells suspended in normal saline (CS blood) with haematocrit around 60%. Platelets and plasma with desired and undesired components are removed. In 50 patients undergoing elective but complicated cardiovascular surgery an average of 4.4 units CS blood were produced. In 3 Jehovah's Witnesses the method was used in combination with immediate preoperative prebleeding and dextran infusion. No blood products were given. The haematocrit was maintained at a safe level subsequent to retransfusion. Platelet counts were never critically low and extremely low total protein did not lead to peripheral or pulmonary oedemas or coagulation problems. In an in vitro study it was shown that extreme dilution of coagulation factors is well tolerated before the clotting time (ACT) is affected. The Cell Saver proved to be an effective, reliable and safe device for autotransfusion of salvaged blood during cardiovascular surgery.

Moderate and extreme haemodilution in open-heart surgery: electrolytes, urea, creatinine and osmolality

Two different programs of treatment, called moderate and extreme haemodilution, respectively, have been compared in patients undergoing aortic valve replacement. Serum electrolytes, urea, creatinine and osmolatity were satisfactory in both groups during and after surgery. A substantial retention of sodium took place in the moderately diluted patients. The extreme group lost more potassium in the urine than the moderate one. A small post-operative rise in creatinine indicates a slight kidney damage in the moderate group. Increased serum urea following moderate dilution might partly be due to increased protein catabolism.