Ultrafiltration Group Research Articles

Comparing Ultrafiltration and Centrifugation During and After Pediatric Cardiopulmonary Bypass

Blood processing techniques related to pediatric cases have previously been generalized from adult experiences. Twenty-two pediatric patients (<25 kilograms) undergoing cardiopulmonary bypass (CPB) for various congenital defects were prospectively randomized into an ultrafiltration or centrifugation group. Sixty-one variables were compared. The blood infused from the ultrafiltration technique contained significantly more heparin (p=0.0001) and more plasma-free hemoglobin (PFH) (p=0.0001) levels than the centrifugation blood. Centrifugation patients had a significantly higher hematocrit (p=0.0066) than the ultrafiltration group twenty minutes postoperatively. The ultrafiltration patients (mean=431.82cc±116.8) received less total packed red blood cell volume before and during bypass than the centrifugation group (mean=534.091cc±113.07). In the centrifugation group, wash volumes showed positive correlation to postoperative blood sodium levels (r= +0.4006, p< 0.05). No significant difference was found between postoperative and preoperative sodium levels (p> 0.05). PFH levels for both groups showed a significant positive correlation to postoperative creatinine levels (r= +.4029, p< 0.05) suggesting decreased postoperative renal function, but a significant negative correlation to post-bypass hematocrit (r= -.4548, p< 0.05). Post-bypass heparin levels in the circuit showed a significant positive correlation to heparin levels in the reinfusion blood for the ultrafiltration group (r= +.8025, p<0.05). Post-bypass PFH level in the circuit showed a significant positive correlation to PFH levels in the reinfusion blood for both groups (r= +.5339, p<0.05). No significant difference existed between the ultrafiltration and centrifugation groups for postoperative prothrombin and partial thromboplastin times. For pediatric cases, the centrifugation technique was found to be superior for post-bypass blood processing based on a higher postoperative patient hematocrit and the presence of less heparin and less PFH in the reinfused blood. The ultrafiltration technique was found to be superior for intraoperative blood processing due to a lower total packed red cell volume addition before and during bypass.

Efficacité respective du Cell Saver ® et de la récupération du circuit de CEC ultrafiltré en chirurgie cardiaque

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). However, 39 patients in group A (65 %) were not given any homologous blood at all, versus 27 in the ultrafiltration group (45 %) (p < 0.0001). The Cell Saver ® associated with isovolaemic haemodilution using blood removed before CPB was therefore the more efficient technique for decreasing homologous transfusion.

Large-volume Paracentesis versus Dialytic Ultrafiltration in the Treatment of Cirrhotic Ascites

We compared the clinical efficacy and safety of large-volume paracentesis and dialytic ultrafiltration in the treatment of refractory ascites in cirrhotic patients. A group of cirrhotic subjects (age 49-80 years) were randomly allocated to either continuous paracentesis (1-1.5 l/hour) or dialytic ultrafiltration until disappearance of ascites. Each patient was maintained on bed rest, fluid restriction (1 l/day) and a low (25 mmol/day) sodium diet for 14 days. Five patients (three in the paracentesis group and two in dialytic ultrafiltration group) developed massive ascites 3-5 months later, and received the crossover treatment. The average volume of fluid removed was similar in the two groups (4.70 +/- 1.47 l for dialytic ultrafiltration versus 4.69 +/- 1.84 l for paracentesis), but the treatment period was significantly shorter with dialytic ultrafiltration. The plasma creatinine significantly increased three days after paracentesis but did not increase in patients treated with dialytic ultrafiltration. There was an initial fall in mean arterial pressure during the first two hours of either treatment; a further fall in blood pressure was observed with paracentesis but not with dialytic ultrafiltration. Pretreatment plasma renin activity was elevated, but was not altered by either treatment. Plasma atrial natriuretic peptide levels were in the high-normal range before treatment. Paracentesis was associated with a delayed fall in plasma atrial natriuretic peptide, while dialytic ultrafiltration induced a modest but significant rise. No complication was experienced with dialytic ultrafiltration in the two weeks following treatment, but four of the eight patients who underwent paracentesis had developed severe complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrafiltration in control of hematocrit and blood volume during cardiopulmonary bypass.

Ultrafiltration as a means to control hematocrit and blood volume during cardiopulmonary bypass was evaluated in two groups of 15 mongrel dogs. In both groups, the fluid input and urinary output were similar (P> 0.20). The amount of filtrate ranged from 950 to 2600 ml (mean 1740.0±426.5 ml), and resulted in an average intraoperative fluid balance of +424.9±131.4 ml. In the control group the fluid balance was +2693.6±222.4 ml, more than in the Ultrafiltration group (P< 0.00l). The mean hematocrit and hemoglobin before ultrafiltration amounted to 13.22% and 4.96g% respectively, whereas after ultrafiltration the variables increased to 23.33g% and 8.28g% respectively (P< 0.00l). Our results suggest that ultrafiltration is a relatively simple, safe and effective method of hemoconcentration during cardiopulmonary bypass.