Minimizing the perfusion system by integration of the components. Does it affect the hematocrit drop and transfused red blood cells? A retrospective audit.

BACKGROUND: We evaluate the affect on the hematocrit (Hct) drop and the amount of transfused red blood cells (RBCs) during cardiopulmonary bypass (CPB) in adult cardiac surgery patients due to minimizing the CPB circuit by using integrated components. METHODS: Two hundred and seventy-two patients were included in this retrospective audit. Patients were assigned to three cohorts: the first cohort consisted of patients operated on with a CPB circuit volume of 1630 ml in 2008; the second cohort of such patients in 2010, with 1380 ml; and the third cohort of such patients in 2011, with 1250 ml. RESULTS: There were no significant differences with respect to patient demographics. The priming volume was consecutively significantly reduced; (1635 ± 84 ml, 1384 ± 72 ml and 1256 ± 130 ml, p<0.0001). A trend of decreased amount of RBCs during CPB was visible (cohort 1630: 98 ± 195 ml, cohort 1380: 35 ± 151 ml and cohort 1250: 48 ± 113 ml, p=0.02). Also, the amount of RBCs during the total CPB procedure shows a decreased trend (cohort 1630: 122 ± 230 ml, cohort 1380: 52 ± 180 ml and cohort 1250: 71 ± 156 ml, p=0.04). Blood loss during CPB was significantly lower in cohorts 1380 and 1250 (1630: 922 ± 378 ml, 1380: 706 ± 347 ml and 1250: 708 ± 418 ml, p<0.0001). The volume of diuresis was significantly larger in cohort 1630 (1630: 1166 ± 800 ml, 1380: 477 ± 530 ml and 1250: 523 ± 504 ml, p<0.0001). The Hct drop at the start and end of CPB was significantly reduced comparing cohort 1630 with cohort 1250 (1630: 32 ± 7%, 1380: 30 ± 7% and 1250: 28 ± 10%, p=0.002) at the start of CPB and (1630: 31 ± 7%, 1380: 29 ± 7% and 1250: 28 ± 8%, p=0.016) at the end of CPB. The Hct values at the start and end of CPB were significantly different between the cohorts (1680: 0.23 ± 0.03 L/L - 0.22 ± 0.02 L/L, 1380: 0.25 ± 0.03 L/L - 0.25 ± 0.03 L/L and 1250: 0.25 ± 0.03 L/L- 0.25 ± 0.03 L/L, p= 0.001 and 0.0001). CONCLUSIONS: Minimizing our CPB circuit by using integrated components has affected the drop of Hct and the amount of transfused RBCs.

The effect of pre-operative blood withdrawal, with or without sequestration, on allogeneic blood product requirements.

UNLABELLED: A common effect of autologous blood withdrawal before cardiopulmonary bypass (CPB) is a decrease in haematocrit (Hct) and haemoglobin (Hb) content. A refinement of this technique is autologous blood withdrawal with the sequestration of platelet rich plasma (PRP) and red blood cells (RBCs). METHODS: One hundred and four patients were included in a randomized study stratified into three groups: the autologous blood withdrawal group (Group 1), the autologous blood withdrawal group with blood loss sequestration (Group 2) and the control group (Control group). In Group 1, the amount of withdrawn blood was transfused after CPB. In Group 2, the RBCs were transfused immediately after sequestration and the PRP was transfused after the termination of CPB. In the Control group, no autologous blood withdrawal was employed. The following variables were analysed: blood loss, blood products transfusion, fluid transfusion, diuresis, haematological and coagulation data and the duration of the operation and intensive care unit stay. RESULTS: We found no significant differences in peri-operative blood loss and transfused blood products among the three groups. There was a trend towards a lower amount of transfused fresh frozen plasma (FFP) for Group 1 (p =0.057) in the operation room (OR). The use of plasma expanders post-CPB was significantly higher in the Control group (p=0.024). RBCs coming from the auto-transfusion device were, for Group 1, significantly lower (p=0.007). The Hb and Hct values in Group 1, at start and end of CPB, were significantly lower (p=0.023-0.003 / 0.001-0.001, respectively). All other parameters were not significantly different. CONCLUSION: there were no significant differences between the study groups. This randomized trial shows that, although sequestration immediately after autologous blood withdrawal has no added value, autologous blood withdrawal in patients with a normal pre-operative Hb and Hct is simple, inexpensive and allows for autologous blood transfusion.

Is the use of albumin in colloid prime solution of cardiopulmonary bypass circuit justified?

BACKGROUND: Albumin in the priming solution precoats the surface of the cardiopulmonary bypass circuit, supposedly causing delayed adsorption of fibrinogen and reduced activation and adhesion of platelets. This action may result in lower transoxygenator resistance. Because our institution uses a colloidal prime solution (Gelofusine), questions were raised about the value of albumin in the prime solution. We decided to focus on the clinical effects of transoxygenator resistance. METHODS: Sixty adults undergoing elective cardiac operations were randomly divided into three groups: a group with 20-g albumin (n = 20), a group with 2-g albumin (n = 20), and a group with no albumin (n = 20) in the 1,600-mL colloidal prime. Patients older than 75 years and patients with a preoperative serum albumin level of 30 g/L or less were excluded. The transoxygenator resistance was measured throughout cardiopulmonary bypass. Beta-thromboglobulin levels were used to study contact activation of platelets. Measures of prothrombin F1,2 fragments were used as a marker of thrombin generation. Body surface area, age, preoperative albumin, hematocrit, hemoglobin, fibrinogen, platelet count, and colloid osmotic pressure levels were compared between groups. RESULTS: Base line characteristics and chosen control measurements were similar for all three populations. When comparing the observed transoxygenator resistance among the three different groups, no significant differences were noted. Prothrombin F1.2 fragments remained low for all the groups without significant differences. In the no-albumin group the level of beta-thromboglobulin appeared to be higher, but the difference was not statistically significant. CONCLUSIONS: Addition of albumin to prime solution in a cardiopulmonary bypass circuit that already contains colloids does not affect the transoxygenator resistance of the COBE Duo flat sheet oxygenator and does not affect prothrombin F1.2 and beta-thromboglobulin levels. Therefore additional costs for the albumin are not justified. Measurement of transoxygenator resistance is a reliable, simple method to determine the effects of a prime solution on the oxygenator surface in vivo.