Haematic antegrade repriming to enhance recovery after cardiac surgery from the perfusionist side

Abstract

Background: New era of cardiac surgery aims to provide an enhanced postoperative recovery through the implementation of every step of the process. Thus, perfusion strategy should adopt evidence-based measures to reduce the impact of cardiopulmonary bypass (CPB). Hematic Antegrade Repriming (HAR) provides a standardized procedure combining several measures to reduce haemodilutional priming to 300 mL. Once the safety of the procedure in terms of embolic release has been proven, the evaluation of its beneficial effects in terms of transfusion and ICU stay should be assessed to determine if could be considered for inclusion in Enhanced Recovery After Cardiac Surgery (ERACS) programs. Methods: Two retrospective and non-randomized cohorts of high-risk patients, with similar characteristics, were assessed with a propensity score matching model. The treatment group (HG) (n = 225) received the HAR. A historical cohort, exposed to conventional priming with 1350 mL of crystalloid confirmed the control group (CG) (n = 210). Results: Exposure to any transfusion was lower in treated (66.75% vs. 6.88%, p < 0.01). Prolonged mechanical ventilation (>10 h) (26.51% vs. 12.62%; p < 0.01) and extended ICU stay (>2 d) (47.47% vs. 31.19%; p < 0.01) were fewer for treated. HAR did not increase early morbidity and mortality. Related savings varied from 581 to 2741.94 $/patient, depending on if direct or global expenses were considered. Discussion: By reducing the gaseous and crystalloid emboli during CPB initiation, HAR seems to have a beneficial impact on recovery and reduces the overall transfusion until discharge, leading to significant cost savings per process. Due to the preliminary and retrospective nature of the research and its limitations, our findings should be validated by future prospective and randomized studies.

Keywords: Cardiopulmonary Bypass; Enhanced recovery after surgery; Haemodilution, blood conservation; Hematic antegrade repriming; Minimized extracorporeal circuits.

Figure 1

Graphical abstract. This figure summarizes the preliminary assessment of HAR’s potential benefits, to enhance postoperative recovery after cardiopulmonary bypass, considering a sample composed of high-risk patients and a propensity score matching methodology for the estimation of the effects. Abbreviations: MiECC – minimized extracorporeal circuit; VAVD – vacuum-assisted venous drainage; <10 h – lower than ten hours; <2 d – lower than two days.

Figure 2

Diagram of sample composition. HAR group was recruited from 01/2014 to 12/2016, while CG was recruited from 01/2012 to 12/2013. Abbreviations: CG – control group; Hgb – Haemoglobin; CPB – cardiopulmonary bypass; ECMO – extracorporeal membrane oxygenation.

Figure 3

Minimized extracorporeal circuit applied during haematic antegrade repriming. Lines (dimensions): 1 – Post-reservoir line (3/8 x 35 cm); 2 – Pre-oxygenator line (3/8 × 40 cm); 3 – proximal arterial line (3/8 × 25 cm); 4 – medial arterial line (3/8 × 55 cm); 5 – distal arterial line (sterile) (3/8 × 135 cm); 6 – distal venous line (sterile) (3/8 × 105 cm); 7 – proximal venous line (3/8 × 40 cm); 8 – arterial recirculation line (clamp included) 1/8 (double male Luer-lock × 70 cm).

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].