FYI Ken, Here are a few abstracts on RAP= retrograde autologous priming
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Ann Thorac Surg. 1998 Mar;65(3):724-30. Related Articles, Links
Comment in:
Ann Thorac Surg. 1998 Sep;66(3):987-8.
Reduction of allogeneic blood transfusions after open heart operations by lowering cardiopulmonary bypass prime volume.
Shapira OM, Aldea GS, Treanor
PR, Chartrand RM, DeAndrade KM, Lazar HL, Shemin RJ.
Department of Cardiothoracic Surgery, Boston Medical Center, Massachusetts 02118, USA.
oshapira@acs.bu.edu
BACKGROUND: Despite recent advances in blood conservation techniques, up to 30% to 80% of patients undergoing open heart operations require allogeneic blood transfusions. A prospective, randomized study was performed to test the effect of lowering cardiopulmonary bypass prime volume (as an additional component of an integrated blood conservation strategy) on clinical outcome and allogeneic blood transfusion. METHODS: One hundred fourteen patients undergoing open heart operations were randomized to either full prime (FP) volume (1,400 mL of Plasmalyte solution) or reduced prime (RP) volume (600 to 800 mL). The reduction of prime volume was achieved by slowly draining the cardiopulmonary bypass circuit into a cell-saving device before the initiation of bypass. Firm transfusion thresholds were observed. RESULTS: There were no significant differences between the groups with respect to baseline characteristics, body surface area, type and urgency of the procedures, perfusion technique, and hematologic profile. Mortality (FP, 1.7%; RP, 0%; p approximately 1.0) and overall morbidity (FP, 28.1%; RP, 22.8%; p = 0.53) were similar. However, transfusion requirements were significantly lower in the RP group: total donor exposure, 3.8 +/- 10.1 versus 1.0 +/- 2.4 units (p = 0.044); percentage of patients transfused, 54% (n = 31) versus 35% (n = 20) (p = 0.036). Twenty-four-hour chest tube drainage was similar: 455 +/- 223 mL for FP versus 472 +/- 173 mL for RP (p = 0.66). The lowest hematocrit on bypass was significantly higher in the RP group: 29.3% +/- 4% versus 26.3% +/- 5.3% (p = 0.009). CONCLUSIONS: Lowering cardiopulmonary bypass prime volume resulted in a significant decrease in allogeneic blood product use. Because postoperative 24-hour chest tube drainage was similar in both groups, and hematocrit during bypass was higher in the RP group, the reduction in allogeneic blood transfusions appears to be related to a decrease in prime-induced hemodilution. This technique is effective, simple, and safe. It therefore should be strongly considered for patients undergoing operations using normothermic or near-normothermic cardiopulmonary bypass who are at high risk for allogeneic blood transfusion.
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Perfusion. 2002 Jan;17(1):69-72. Related Articles, Links
Low-prime perfusion circuit and autologous priming in CABG surgery on a Jehovah's Witness: a case report.
Brest van Kempen AB, Gasiorek JM, Bloemendaal K, Storm van Leeuwen RP, Bulder ER.
Department of Extracorporeal Circulation, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
r.brestvankempen@planet.nl
Cardiac surgery on Jehovah's Witnesses is a great challenge for the cardiothoracic surgery team and especially for the perfusionist. To reduce the risk of surgery in these patients, a very small extracorporeal circuit was designed to decrease the amount of priming volume and thereby the degree of hemodilution. A small bypass system was built, consisting of a 3/8-in. arterial line and a 3/8-in. venous line, a venous collapsible reservoir, a centrifugal pump, a hollow fiber oxygenator and a cell saver reservoir. The circuit priming volume was 650 ml. By using antegrade and retrograde autologous priming, the total amount of priming was reduced to +/-50 ml. Bypass time was 63 min with an average blood flow of 5300+/-114 ml/min and postmembrane pressures of 180+/-45 mmHg. Venous line pressure was monitored and kept between -8 and -20 mmHg with a mean arterial pressure (MAP) of 55+/-12.3 mmHg. The hematocrit before extracorporeal circulation (ECC) was 36%, per-ECC 35% and post-ECC 35%. On the fifth postoperative day, the hematocrit was 40%. The patient was discharged 7 days after surgery. A low-prime circuit, in combination with autologous priming, seems to be safe and effective in avoiding the use of banked blood.
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Ann Thorac Surg. 2002 Jun;73(6):1912-8. Related Articles, Links
Retrograde autologous priming of the cardiopulmonary bypass circuit reduces blood transfusion after coronary artery surgery.
Balachandran S, Cross MH, Karthikeyan S, Mulpur A, Hansbro SD, Hobson P.
The Yorkshire Heart Centre, Leeds General Infirmary, United Kingdom.
BACKGROUND: Hemodilution occurring with cardiopulmonary bypass imposes a risk for blood transfusion. Autologous priming of the cardiopulmonary bypass circuit at the initiation of bypass partially replaces the priming solution with autologous blood. We examined the efficacy of autologous priming of the circuit in reducing blood transfusion. METHODS: One hundred and four patients were entered into a prospective, randomized, controlled study. Initiation of cardiopulmonary bypass was with or without autologous priming. RESULTS: With autologous priming, a mean volume of 808.8 +/- 159.3 mL of priming solution was replaced with autologous blood. This allowed a higher hematocrit value on admission to the intensive care unit and at discharge from hospital. In all, 49% of the control group required a blood transfusion compared with 17% from the autologous priming group (p = 0.0007). The mean volume of blood transfused was 277.6 +/- 363.8 mL in the control group compared with 70.1 +/- 173.5 mL in the autologous priming group (p = 0.0005). CONCLUSIONS: Retrograde autologous priming of the bypass circuit reduces homologous blood transfusion owing to the reduction in bypass circuit priming volume.