34 J . Blanco-Morillo et al .: J Extra Corpor Technol 2023 , 55 , 30 – 38
Figure 4 . HAR , the 6 steps procedure . Step 1 : The circuit is primed with 1000 mL of a balanced crystalloid solution . Then , venous and arterial lines are clamped . Step 2 : Venous line content is drained to the reservoir by activating vacuum-assisted venous drainage ( VAVD ) and removing the venous clamp . Step 3 : removing the arterial line clamp that is proximal to the patient and opening the arterial line recirculation , autologous blood discurs retrogradely pushing the crystalloid priming to the reservoir . Then , the arterial recirculation line clamp is closed to avoid blood mixing in the reservoir . Step 4 : By opening the recirculation line of the oxygenator and setting the centrifugal pump ( CP ) to 2000 rpm , crystalloid priming is discarded into the collector bag until zero level in the reservoir is reached . Step 5 : A clamp is placed after the reservoir and arterial line recirculation is opened again . Thus , retrogradely , 300 mL of arterial blood is sequestered in the reservoir ( 100 – 200 mL / min ). Step 6 : Setting CP to 2000 rpm and opening the recirculation line of the oxygenator and removing the clamp after the reservoir , CP and oxygenator are reprimed with autologous blood , displacing the priming and GME to the collector bag reducing haemodilution to only 300 mL . * CPB is initiated with VAVD activation once the venous return is obtained . Adapted from : [ 17 ].
Otherwise , no significant differences were found between groups in terms of early mortality ( CG 12.51 % vs . HG 5.5 %, p = 0.056 ), postoperative bleeding ( Bleeding > 400 : CG = 57.6 % vs . HG = 48.9 %, p = 0.14 ) and the incidence of postoperative complications ( p > 0.05 ) ( Table 3 ).
Considering the public unitary prices per blood component and per day of ICU stay in our region , the minimum cost saving related to the application of HAR was estimated as 581.7 $/ patient ( Table 4 ).
Discussion
The transfusional effect estimated for HAR seemed to be superior to the isolated effect of MiECC , VAVD , RAP , and CPB initiation with an empty venous line . Albeit MiECC was recommended as I-A for blood conservation a decade ago , current evidence indicates that the overall effect in outcomes is controversial , due to not finding significant differences in terms of reoperation for bleeding , 30-day mortality , myocardial infarction , renal , and cerebral outcomes [ 6 ]. RAP nomenclature is also tainted by several limitations like the heterogeneity in practice and Vranken et al . warned about the high risk of biases behind the current level of recommendation related to the technique / s [ 8 ].
Regarding the use of VAVD , when applied in a range of suction not lower than �40 mmHg , seems to be a safe practice that contributes to reducing hemodilution and transfusion . The initiation of CPB with an empty venous line is a controverted perfusion strategy to reduce circulating volume and hemodilution , being required after the completion of HAR . Despite possible concerns about the emboli impact of any of both , there is recent evidence indicating that HAR represents a protective