OBJECTIVES Neurodevelopmental injury after cardiac surgery using cardiopulmonary bypass (CPB) for congenital heart defects is common, but the mechanism behind this injury is unclear. This study examines the impact of CPB on cerebral mitochondrial reactive oxygen species (ROS) generation and mitochondrial bioenergetics. METHODS Twenty-three piglets (mean weight 4.2 ± 0.5 kg) were placed on CPB for either 1, 2, 3 or 4 h (n = 5 per group) or underwent anaesthesia without CPB (sham, n = 3). Microdialysis was used to measure metabolic markers of ischaemia. At the conclusion of CPB or 4 h of sham, brain tissue was harvested. Utilizing high-resolution respirometry, with simultaneous fluorometric analysis, mitochondrial respiration and ROS were measured. RESULTS There were no significant differences in markers of ischaemia between sham and experimental groups. Sham animals had significantly higher mitochondrial respiration than experimental animals, including maximal oxidative phosphorylation capacity of complex I (OXPHOSCI) (3.25 ± 0.18 vs 4-h CPB: 1.68 ± 0.10, P < 0.001) and maximal phosphorylating respiration capacity via convergent input through complexes I and II (OXPHOSCI+CII) (7.40 ± 0.24 vs 4-h CPB: 3.91 ± 0.20, P < 0.0001). At 4-h, experimental animals had significantly higher ROS related to non-phosphorylating respiration through complexes I and II (ETSCI+CII) than shams (1.08 ± 0.13 vs 0.64 ± 0.04, P = 0.026). CONCLUSIONS Even in the absence of local markers of ischaemia, CPB is associated with decreased mitochondrial respiration relative to shams irrespective of duration. Exposure to 4 h of CPB resulted in a significant increase in cerebral mitochondrial ROS formation compared to shorter durations. Further study is needed to improve the understanding of cerebral mitochondrial health and its effects on the pathophysiology of neurological injury following exposure to CPB.

Introduction: A device that may help attenuate the amount of homologous blood product given to pediatric cardiac surgical patients is the autotransfusion device. Three separate autotransfusion devices were selected for evaluation. The Sorin Xtra, Fresenius Continuous Autotransfusion System Plus (CATS*plus), and the Fresenius Continuous Autotransfusion System Smart (CATSmart) were evaluated based on the mechanical processes of each device, hematocrit value of the salvaged packed red cell product, time of processing, and the advantageous accessories with each device. Methods: Each of the autotransfusion devices were used to collect salvageable blood from the surgical field as well as to process residual blood from the cardiopulmonary bypass circuit after decannulation. The cell salvage process was performed in accordance with the manufacturer’s instructions for use and the recommended settings for processing and washing. The Sorin Xtra device had the 55 mL bowl set up for all cases, while the Fresenius continuous autotransfusion systems utilized the standard disposable for each device. Results: Each cell salvage device was employed during 30 pediatric cardiac surgery procedures, and data for each device, was broken down into four groups based on patient weight (0-10, 10-20, 20-40, and >40 kg). For all patient sizes, the Sorin Xtra tended to produce the greatest volume of cell saver product (55-825 mL) as compared to the CATS*plus and CATSmart devices (7-550 mL and 0-860 mL, respectively). The Continuous Autotransfusion System Smart tended to produce the highest hematocrit product, ranging from 44 to 81%. Discussion: Through this evaluation, it was determined the continuous autotransfusion systems provided the highest hematocrit with the lowest recovered packed red cell volume, while the Sorin Xtra packed red cell product showed to have a lower hematocrit with a larger packed red cell volume. Each device proved effective within our pediatric population.

Background: Vacuum-assisted venous drainage has gained widespread use within the pediatric perfusion community for use during cardiopulmonary bypass. It is questioned whether its efficiency may be compromised with application of excessive cardiotomy suction to the infant hard-shell venous reservoir. An in vitro simulation circuit was used to research this phenomenon. A comparison of three different infant hard-shell venous reservoirs also took place to determine if one reservoir type was more advantageous when handling cardiotomy suction. The reservoirs tested were the Maquet VHK 11000, Medtronic Affinity Pixie, and Terumo Capiox FX05. Methods: The in vitro simulation circuit consisted of a 1 L reservoir bag that was cannulated at one access point with an Edwards Lifesciences 10Fr aortic cannula and the other access area with an Edwards Lifesciences 10Fr right angle venous cannula and 12Fr right angle venous cannula that were joined together. Key points of measurement and response variables were the pressures on the connection of the venous cannulas, inlet of the venous reservoir, and flow through the venous line. Vacuum was applied and manipulated with a Maquet VAVD Controller to settings of −20 mmHg, −30 mmHg, –40 mmHg, −50 mmHg, and −60 mmHg. Cardiotomy suction was added at settings of 1 LPM, 2 LPM, 3 LPM, and 4 LPM. Values from each response variable were monitored and recorded. These data were utilized to compare the reservoirs with a random coefficient model for each response variable. Conclusions: There is an adverse effect of excessive cardiotomy suction on the efficacy of vacuum-assisted venous drainage in infant hard-shell venous reservoirs. There is no significant difference between the VHK 11000, Pixie, and FX05 regarding their ability to handle this occurrence. An important discovery was that the FX05 showed a greater transfer of vacuum to the venous cannulas and reservoir inlet.