Conventional versus minimally invasive extra-corporeal circulation in patients undergoing cardiac surgery: A randomized controlled trial (COMICS).

INTRODUCTION: The trial hypothesized that minimally invasive extra-corporeal circulation (MiECC) reduces the risk of serious adverse events (SAEs) after cardiac surgery operations requiring extra-corporeal circulation without circulatory arrest. METHODS: This is a multicentre, international randomized controlled trial across fourteen cardiac surgery centres including patients aged ≥18 and <85 years undergoing elective or urgent isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR) surgery, or CABG + AVR surgery. Participants were randomized to MiECC or conventional extra-corporeal circulation (CECC), stratified by centre and operation. The primary outcome was a composite of 12 post-operative SAEs up to 30 days after surgery, the risk of which MiECC was hypothesized to reduce. Secondary outcomes comprised: other SAEs; all-cause mortality; transfusion of blood products; time to discharge from intensive care and hospital; health-related quality-of-life. Analyses were performed on a modified intention-to-treat basis. RESULTS: The trial terminated early due to the COVID-19 pandemic; 1071 participants (896 isolated CABG, 97 isolated AVR, 69 CABG + AVR) with median age 66 years and median EuroSCORE II 1.24 were randomized (535 to MiECC, 536 to CECC). Twenty-six participants withdrew after randomization, 22 before and four after intervention. Fifty of 517 (9.7%) randomized to MiECC and 69/522 (13.2%) randomized to CECC group experienced the primary outcome (risk ratio = 0.732, 95% confidence interval (95% CI) = 0.556 to 0.962, p = 0.025). The risk of any SAE not contributing to the primary outcome was similarly reduced (risk ratio = 0.791, 95% CI 0.530 to 1.179, p = 0.250). CONCLUSIONS: MiECC reduces the relative risk of primary outcome events by about 25%. The risk of other SAEs was similarly reduced. Because the trial terminated early without achieving the target sample size, these potential benefits of MiECC are uncertain.

Implications of High Sensitivity Troponin Levels After Lung Transplantation.

Trends in high-sensitivity cardiac troponin I (hs-cTnI) after lung transplant (LT) and its clinical value are not well stablished. This study aimed to determine kinetics of hs-cTnI after LT, factors impacting hs-cTnI and clinical outcomes. LT recipients from 2015 to 2017 at Toronto General Hospital were included. Hs-cTnI levels were collected at 0-24 h, 24-48 h and 48-72 h after LT. The primary outcome was invasive mechanical ventilation (IMV) >3 days. 206 patients received a LT (median age 58, 35.4% women; 79.6% double LT). All patients but one fulfilled the criteria for postoperative myocardial infarction (median peak hs-cTnI = 4,820 ng/mL). Peak hs-cTnI correlated with right ventricular dysfunction, >1 red blood cell transfusions, bilateral LT, use of EVLP, kidney function at admission and time on CPB or VA-ECMO. IMV>3 days occurred in 91 (44.2%) patients, and peak hs-cTnI was higher in these patients (3,823 vs. 6,429 ng/mL, p < 0.001 after adjustment). Peak hs-cTnI was higher among patients with had atrial arrhythmias or died during admission. No patients underwent revascularization. In summary, peak hs-TnI is determined by recipient comorbidities and perioperative factors, and not by coronary artery disease. Hs-cTnI captures patients at higher risk for prolonged IMV, atrial arrhythmias and in-hospital death.

Beyond the Surgical Safety Checklist: Using Intraoperative Handoff to Facilitate Team Situation Awareness in the OR.

BACKGROUND: The surgical safety checklist (SSC) has been credited with improving team situation awareness (SA) in the operating room. Although the SSC may support team SA at the outset of the operative case, intraoperative handoff provides an opportunity for either SA breakdown or, more preferably, SA reinforcement. High-functioning surgical teams demonstrate a high level of continued SA, whereas teams deficient in SA are more likely to be affected by surgical errors and adverse events. To date, no interprofessional intraoperative tools exist to support team SA beyond the SSC. METHODS: This study was divided into 2 phases. The first used qualitative methods to (1) characterize intraoperative handoff processes across surgery, nursing, anesthesia, and perfusion, and (2) identify cultural factors that shaped handoff practices. Data for phase one were collected over 38 observation days and 41 brief interviews. Phase 2, informed by phase 1, used a modified Delphi process to create a tool for use during intraoperative handoff. Data were analyzed iteratively. RESULTS: Handoff practices were not standardized and rarely involved the entire team. In addition we uncovered cultural factors-specifically assumptions held by participants-that hindered team communication during handoff. Assumptions included: (1) team members are interchangeable, (2) trained individuals are able to determine when it is appropriate to handoff without consulting the OR team. Despite claims of improved teamwork resulting from the SSC, many participants held a fragmented view of the OR team, resulting in communication challenges during handoff. Findings from both phases of our study informed the development of multidisciplinary intraoperative handoff tools to facilitate shared team situation awareness and a shared mental model. CONCLUSIONS: Intraoperative handoff occurs frequently, and offers the opportunity for either renewed or fractured team SA beyond the SSC.

Platelet preservation in cardiac surgery using minimally invasive extracorporeal circulation versus optimized cardiopulmonary bypass.

BACKGROUND: Minimally invasive extracorporeal circulation (MiECC) is employed as a strategy to attenuate the physiologic disturbance caused by cardiopulmonary bypass. The aim of this study was to compare the coagulation profile of MiECC to an optimized conventional extracorporeal circuit (OpECC) with regards to platelet function, rotational thromboelastometry and blood product usage. METHODS: A retrospective analysis of coronary artery bypass grafting operations using either MiECC or OpECC was performed at a single institution. RESULTS: A total of 112 patients were included, with 61 receiving MiECC and 51 OpECC patients. OpECC patients had a significantly larger BSA (1.95+/- 0.22m2 vs 1.88 +/- 0.18m2, p = 0.034), than those who received MiECC. No difference between groups was observed regarding red blood cell, plasma, and platelet transfusions. Functional platelet count during the warming phase of cardiopulmonary bypass was found to be higher in the MiECC group ((136 (102-171) x109/L vs 109 (94-136) x109/L), p = 0.027), as were functional platelets as a percent of total platelet count ((86 (77-91)% vs 76 (63-82)%), p = 0.003). There were no significant differences between other outcomes such as operative mortality, incidence of stroke, and intensive care unit length of stay. CONCLUSION: While we did not see a difference in blood transfusions, MiECC resulted in a statistically significant advantage over OpECC with regards to preservation of functional platelets.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery.

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Titrated versus conventional anticoagulation management for thrombin generation in cardiac surgery: a randomized controlled trial.

PURPOSE: Optimal heparin titration during cardiopulmonary bypass (CPB) may reduce coagulation system activation and preserve hemostatic function post-CPB. Our objective was to assess if the Heparin Management System (HMS) Plus improves heparin titration, thereby leading to higher thrombin generation post-CPB compared with activated clotting time (ACT)-guided management. METHODS: We conducted a randomized controlled trial of 100 patients undergoing cardiac surgery with CPB at a single center. A total of 50 patients were randomized to conventional ACT-guided management, and 50 to the HMS Plus system. The primary outcome was change in thrombin generation post-CPB compared with baseline, as assessed by calibrated automated thrombography. Secondary outcomes included intraoperative blood loss, chest drain output up to 72 hr, and transfusions. In an exploratory analysis, we compared the quintile of patients with the highest average heparin concentration on CPB (≥ 4.0 mg⋅kg-1) with the rest of the cohort. RESULTS: A total of 100 patients were included in an intent-to-treat analysis. We observed no difference in post-CPB thrombin generation or secondary outcomes. However, patients in the HMS Plus group had higher average heparin concentrations while on CPB than patients in the conventional management group did (mean difference, -0.21; 95% confidence interval, -0.42 to -0.01). The quintile of patients with the highest average heparin concentration (4.0 mg⋅kg-1) had higher thrombin generation post-CPB than the rest of the cohort did. CONCLUSIONS: The HMS Plus system did not show significant benefits in thrombin generation, bleeding outcomes, or transfusion in patients undergoing cardiac surgery with CPB. Higher average heparin concentrations on CPB were associated with higher post-CPB thrombin generation. STUDY REGISTRATION: www. CLINICALTRIALS: gov (NCT03347201); first submitted 12 October 2017.

RéSUMé: OBJECTIF: Un titrage optimal de l'héparine pendant la circulation extracorporelle (CEC) peut réduire l'activation du système de coagulation et préserver la fonction hémostatique après la CEC. Notre objectif était d'évaluer si le système de gestion de l'héparine HMS Plus améliorait le titrage de l'héparine, entraînant ainsi une génération de thrombine plus élevée après la CEC par rapport à la gestion guidée par le temps de coagulation activé (ACT). MéTHODE: Nous avons réalisé une étude randomisée contrôlée de 100 patients bénéficiant d'une chirurgie cardiaque sous CEC dans un seul établissement. Au total, 50 patients ont été randomisés à une gestion conventionnelle guidée par l'ACT et 50 à une gestion guidée par le système HMS Plus. Le critère d'évaluation principal était la variation de la génération de thrombine post-CEC par rapport aux valeurs de base, telles qu'évaluées par thrombographie calibrée automatisée. Les critères secondaires comprenaient les pertes sanguines peropératoires, le drainage thoracique jusqu'à 72 heures et les transfusions. Dans une analyze exploratoire, nous avons comparé le quintile de patients ayant la concentration moyenne d'héparine la plus élevée sous CEC (≥ 4,0 mg⋅kg-1) au reste de la cohorte. RéSULTATS: Au total, 100 patients ont été inclus dans une analyze en intention de traiter. Nous n'avons observé aucune différence dans la génération de thrombine post-CEC ou dans nos critères d'évaluation secondaires. Cependant, les patients du groupe HMS Plus présentaient des concentrations moyennes d'héparine plus élevées sous CEC que les patients du groupe de gestion conventionnelle (différence moyenne, -0,21; intervalle de confiance à 95 %, -0,42 à -0,01). Le quintile de patients ayant la concentration moyenne d'héparine la plus élevée (4,0 mg⋅kg-1) avaient une génération de thrombine post-CEC plus élevée que le reste de la cohorte. CONCLUSION: Le système HMS Plus n'a pas montré d'avantages significatifs dans la génération de thrombine, les issues hémorragiques ou la transfusion chez les patients bénéficiant d'une chirurgie cardiaque sous CEC. Des concentrations moyennes d'héparine plus élevées sous CEC ont été associées à une génération de thrombine post-CEC plus élevée. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT03347201); soumis pour la première fois le 12 octobre 2017.

Protamine Test Dose: Impact on Activated Clotting Time and Circuit Integrity.

BACKGROUND: Recurrent observation of clot in the cardiopulmonary bypass circuit after the administration of a protamine test dose (PTD) prompted concern over the effects of PTDs on patient activated clotting times (ACTs). METHODS: Data were prospectively collected on 120 patients who had cardiopulmonary bypass while undergoing a variety of cardiac surgical procedures from July to October 2018 at the Toronto General Hospital, Toronto, Canada. ACTs were documented before cardiopulmonary bypass termination, after PTDs, and after protamine full doses. Statistical analysis was completed using a paired t test. RESULTS: The average PTD was calculated to be 36 ± 21 mg or 11% ± 7% of the full protamine dose of 367 ± 153 mg. This "test" dose ranged from 1% to 67% of full dose depending on the anesthetist. Post-PTD ACTs were widely variable. On average, there was a 40% ± 25% drop from the last ACT during cardiopulmonary bypass (650 ± 155 seconds) to the ACT after PTD (376 ± 153 seconds) (P < .0001). In fact, 81% ± 5% of the patients' post-PTD ACTs were lower than the institutional ACT standard of 480 seconds for safe cardiopulmonary bypass initiation. CONCLUSIONS: Regardless of the PTD, there is no reliable way to predict how a patient's ACT will respond to a PTD. Clot formation is possible and circuit integrity is at risk when pump suction devices are continuously in use during PTD administration. Therefore, the study investigators strongly recommend that the direct recovery of mediastinal shed blood into the pump circuit be discontinued before any amount of protamine is administered to the patient.

The association of thrombin generation with bleeding outcomes in cardiac surgery: a prospective observational study.

BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with coagulopathic bleeding. Impaired thrombin generation may be an important cause of coagulopathic bleeding but is poorly measured by existing hemostatic assays. We examined thrombin generation during cardiac surgery, using calibrated automated thrombography, and its association with bleeding outcomes. METHODS: We conducted a prospective observational study in 100 patients undergoing cardiac surgery with CPB. Calibrated automated thrombography parameters were expressed as a ratio of post-CPB values divided by pre-CPB values. The association of thrombin generation parameters for bleeding outcomes was compared with conventional tests of hemostasis, and the outcomes of patients with the most severe post-CPB impairment in thrombin generation (≥ 80% drop from baseline) were compared with the rest of the cohort. RESULTS: All 100 patients were included in the final analysis, with a mean age of 63 (12) yr, 31 (31%) female, and 94 (94%) undergoing bypass and/or valve surgery. Post-CPB, peak thrombin decreased by a median of 73% (interquartile range [IQR], 49-91%) (P < 0.001) and total thrombin generation, expressed as the endogenous thrombin potential (ETP), decreased 56% [IQR, 30-83%] (P < 0.001). In patients with ≥ 80% decrease in ETP, 21% required re-exploration for bleeding compared with 7% in the rest of the cohort (P = 0.04), and 48% required medical or surgical treatment for hemostasis compared with 27% in the rest of the cohort (P = 0.04). CONCLUSIONS: Thrombin generation is significantly impaired by CPB and associated with higher bleeding severity. Clinical studies aimed at the identification and treatment of patients with impaired thrombin generation are warranted.

RéSUMé: CONTEXTE: La chirurgie cardiaque avec circulation extracorporelle (CEC) est associée à des saignements sur coagulopathie. L'altération de la génération de thrombine peut constituer une cause importante de saignement sur coagulopathie, mais elle est mal mesurée par les tests d'hémostase existants. Nous avons examiné la génération de thrombine pendant la chirurgie cardiaque à l'aide d'une thrombographie automatisée calibrée ainsi que son association avec les issues hémorragiques. MéTHODE: Nous avons réalisé une étude observationnelle prospective portant sur 100 patients bénéficiant d'une chirurgie cardiaque sous CEC. Les paramètres de thrombographie automatisée calibrée ont été exprimés sous forme du rapport entre les valeurs post-CEC divisées par les valeurs pré-CEC. L'association des paramètres de génération de thrombine pour les issues hémorragiques a été comparée aux tests conventionnels de l'hémostase, et les issues des patients présentant l'altération post-CEC la plus prononcée dans la génération de thrombine (baisse ≥ 80 % par rapport aux valeurs de base) ont été comparées au reste de la cohorte. RéSULTATS: Les 100 patients ont tous été inclus dans l'analyse finale, avec un âge moyen de 63 (12) ans, 31 (31 %) femmes et 94 (94 %) subissant une chirurgie de pontage et / ou une chirurgie valvulaire. Après la CEC, le pic de thrombine a diminué d'une médiane de 73 % (écart interquartile [ÉIQ], 49 à 91 %) (P < 0,001) et la génération de thrombine totale, exprimée en potentiel de thrombine endogène (PTE), a diminué de 56 % [ÉIQ, 30­83 %] (P < 0,001). Chez les patients présentant une diminution ≥ 80 % du PTE, 21 % ont nécessité une nouvelle exploration pour dépister les saignements, comparativement à 7 % dans le reste de la cohorte (P = 0,04), et 48 % ont nécessité un traitement médical ou chirurgical pour l'hémostase, comparativement à 27 % dans le reste de la cohorte (P = 0,04). CONCLUSION: La génération de thrombine est significativement altérée par la CEC et associée à des saignements plus graves. Des études cliniques visant à identifier et à traiter les patients présentant une altération de la génération de thrombine sont recommandées.

A comparative analysis of four activated clotting time measurement devices in cardiac surgery with cardiopulmonary bypass.

BACKGROUND: In cardiac surgery on cardiopulmonary bypass (CPB), heparin anticoagulation is monitored by point-of-care measurement of activated clotting time (ACT). The objective of this study was to compare four ACT systems in cardiac surgery in terms of their reproducibility, agreement and potential clinical impact at relevant medical decision points. METHODS: The study included 40 cardiac surgery patients. Samples were taken at five time points before (T1), after heparinization for CPB (T2, T3, T4), and after heparin reversal (T5). The reproducibility, correlation, and differences in ACT values were assessed with two devices from each of the four ACT systems: Instrumentation Laboratory Hemochron Elite (Hmch), Medtronic HMS Plus (HMS), Abbott i-STAT, and Helena Abrazo. Subrange analyses were performed for low ACT values (results from T1, T5) and high ACT values (results from T2, T3, T4). RESULTS: Within-system analysis showed strong linear correlation between paired measurements (R = 0.968-0.993). However, Hmch showed poorer reproducibility with highest proportion of values that exceed a difference of 10% and highest overall standard error of 74 seconds across the measurement range compared to that of the others (range 39-47 seconds, respectively). For inter-system comparison, using Hmch as reference, ACTs were strongly correlated as follows: HMS (R = 0.938), i-STAT (R = 0.911), and Abrazo (R = 0.911). Agreement analysis in the high ACT range showed HMS tended to have higher ACT values with +11% bias over Hmch, whereas i-STAT (-8% bias) and Abrazo (-13% bias) tended to underestimate. Post-protamine ACT results were dependent on device type where Hmch yielded highest post-protamine ACT (+13% higher than baseline) compared to -16% for HMS, -10% for iSTAT and 0% for Abrazo. CONCLUSIONS: Each device had individual reproducibility and biases, which may impact peri-operative heparin management. Careful validation must be undertaken when adopting a different method as decision limits would be affected. Clinicians should also be cautious using ACT as the only indicator for full heparin reversal.

A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation.

Fifty-years following the first successful report, cardiac transplantation remains the gold-standard treatment for eligible patients with advanced heart failure. Multiple small-animal models of heart transplantation have been used to study the acute and long-term effects of novel therapies. However, few are tested and demonstrated success in clinical trials. It is of critical importance to evaluate new therapies in a clinically relevant large-animal model for efficient and reliable translation of basic studies' findings. Here, we describe a pre-clinical large-animal (porcine) model of orthotopic heart transplantation that has been firmly established and previously used to investigate novel cardioprotective strategies. This procedure focuses on acute ischemia-reperfusion injury and is a reliable method to investigate novel interventions which have been tested and validated in smaller experimental models, such as the murine model. We demonstrate its usefulness in assessing cardiac performance during the early post-transplantation period and other potential possibilities enabled by the model.

Hearts Donated After Circulatory Death and Reconditioned Using Normothermic Regional Perfusion Can Be Successfully Transplanted Following an Extended Period of Static Storage.

BACKGROUND: There has been an increased interest in donation after circulatory death (DCD) to expand donor pool for cardiac transplantation. Normothermic regional perfusion (NRP) allows in situ assessment of DCD hearts, allowing only acceptable organs to be procured. We sought to determine if extended cold storage was possible for DCD hearts following NRP and to compare hearts stored using standard cold storage with a novel cardioprotective solution designed for room temperature storage. METHODS AND RESULTS: Donor pigs underwent hypoxic cardiac arrest (DCD) followed by 15 minutes of warm ischemia and resuscitation on NRP. They were then randomly assigned to static storage with histidine-tryptophan-ketoglutarate (HTK) at 4°C (HTK group, n=5) or SOM-TRN-001 at 21°C (SOM group, n=5). Conventional beating-heart donations were used as controls (n=4). Fourteen transplants were successfully performed. HTK hearts showed initial dysfunction following reperfusion; however, they demonstrated significant recovery up to 3 hours post-transplant. No significant differences were seen between HTK and control hearts post-transplantation (cardiac index: control 49.5±6% and HTK 48.5±5% of baseline). SOM improved myocardial preservation; hearts showed stable contractility after transplantation (cardiac index: 113.0±43% of NRP function) and improved diastolic function compared with HTK. Preservation in SOM also significantly reduced proinflammatory cytokine production and release following transplantation and partially prevented endothelial dysfunction. CONCLUSIONS: DCD hearts stored using a standard preservation solution demonstrated comparable post-transplantation myocardial function to standard controls. Thus, short periods of cold storage following successful NRP and documented adequate function is an acceptable strategy for DCD hearts. Preservation in SOM at room temperature is feasible and can improve cardiac recovery by minimizing endothelial dysfunction and tissue injury.

Normothermic ex vivo liver perfusion using steen solution as perfusate for human liver transplantation: First North American results.

The European trial investigating normothermic ex vivo liver perfusion (NEVLP) as a preservation technique for liver transplantation (LT) uses gelofusine, a non-US Food and Drug Administration-approved, bovine-derived, gelatin-based perfusion solution. We report a safety and feasibility clinical NEVLP trial with human albumin-based Steen solution. Transplant outcomes of 10 human liver grafts that were perfused on the Metra device at 37 °C with Steen solution, plus 3 units of erythrocytes were compared with a matched historical control group of 30 grafts using cold storage (CS) as the preservation technique. Ten liver grafts were perfused for 480 minutes (340-580 minutes). All livers cleared lactate (final lactate 1.46 mmol/L; 0.56-1.74 mmol/L) and produced bile (61 mL; 14-146 mL) during perfusion. No technical problems occurred during perfusion, and all NEVLP-preserved grafts functioned well after LT. NEVLP versus CS had lower aspartate aminotransferase and alanine aminotransferase values on postoperative days 1-3 without reaching significance. No difference in postoperative graft function between NEVLP and CS grafts was detected as measured by day 7 international normalized ratio (1.1 [1-1.56] versus 1.1 [1-1.3]; P = 0.5) and bilirubin (1.5; 1-7.7 mg/dL versus 2.78; 0.4-15 mg/dL; P = 0.5). No difference was found in the duration of intensive care unit stay (median, 1 versus 2 days; range, 0-8 versus 0-23 days; P = 0.5) and posttransplant hospital stay (median, 11 versus 13 days; range, 8-17 versus 7-89 days; P = 0.23). Major complications (Dindo-Clavien ≥ 3b) occurred in 1 patient in the NEVLP group (10%) compared with 7 (23%) patients in the CS group (P = 0.5). No graft loss or patient death was observed in either group. Liver preservation with normothermic ex vivo perfusion with the Metra device using Steen solution is safe and results in comparable outcomes to CS after LT. Using US Food and Drug Administration-approved Steen solution will avoid a potential regulatory barrier in North America. Liver Transplantation 22 1501-1508 2016 AASLD.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS).

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

A prospective comparison of the platelet sequestration ability of three autotransfusion devices.

Although current autotransfusion devices have platelet sequestration capabilities, each has a unique technology to achieve the final platelet product. The purpose of this study was to assess the quality and quantity of platelets sequestered by three different autotransfusion devices. The three commercially available autotransfusion devices evaluated were Fresenius C.A.T.S (closed spiral chamber), Cobe BRAT 2 (Baylor bowl), and Haemonetic Cell Saver 5 (Latham bowl). Platelet sequestration was preformed in the automatic mode following the manufacturer's recommended sequestration protocols. The total number of platelets sequestered, percent recovery, and percent platelet function were assessed. Each device behaved similarly. There was a 2- to 3-fold increase in platelet count compared with baseline with only approximately 50-60% recovery, whereas there was approximately a 10% decrease in platelet function after processing compared with baseline. No statistical difference was noted in platelet function between the respective machines. However, there was a significant loss of platelet function observed with the actual process regardless of autotransfusion device used.

Partial bowls using the Haemonetics Cell Saver 5: does it produce a quality product?

Controversy still exists on the validity of processing a partial bowl during the collection of shed blood lost through surgery during cell salvaging. The purpose of this study was to assess the quality of red blood cells produced from a partial bowl of autologous suctioned blood using the Haemonetics Cell Saver 5. Suctioned blood was collected from 17 patients undergoing cardiac surgery. A partially filled cell saver bowl was washed with 1500 mL of NaCl. Reservoir and processed blood samples were examined for potassium, leukocytes, hematocrit, platelets, and plasma-free hemoglobin and then compared with 22 previously studied full bowls. Results are summarized in the table below: In conclusion, the Haemonetics Cell Saver 5 can produce a quality product from washing a partial bowl with a better washout of white blood cells compared with a full bowl. However, there is a reduction in red blood cell recovery.

Quality of red blood cells using the Dideco Electa autotransfusion device.

The purpose of this study was to evaluate the quality of washed, concentrated red blood cells (RBCs) produced by the new Electa autotransfusion device from Cobe Cardiovascular (Dideco). Blood was collected intraoperatively in 16 patients undergoing cardiac surgery for whom routine cell savage was being used and then washed using the Electa. According to the manufacture's protocol. 125-mL bowls were used in the standard wash program. Reservoir and washed RBCs were analyzed for platelets (PLTs), leukocytes (WBCs), potassium (K+), and plasma-free hemoglobin (PFH) removal, as well as, hematocrit (Hct) and RBC recovery. The Electa cell saver produced a product with an average Hct of 58+/-5% and a RBC recovery rate of 87+/-10%. Its removal of waste products resulted in the washout of 54+/-18% WBCs, 87+/-6% PLTs, 91+/-4% K+, and 77+/-17% PFH. The Electa produces a good-quality washed RBC product that is comparable with other autotransfusion devices on the market.

The influence of cardiopulmonary bypass flow characteristics on the clinical outcome of 1820 coronary bypass patients.

OBJECTIVE: To determine whether pulsatile perfusion is clinically beneficial for adult cardiac operations. METHODS: Data concerning consecutive patients undergoing isolated coronary bypass surgery (n=1820) from January 1, 1997 to July 31, 1999 were reviewed. RESULTS: Nine hundred fifteen patients received pulsatile perfusion (PP) while perfusion in the remaining 905 patients was nonpulsatile (NP). Patients in the PP group were older (64.0 +/- 9.2 years versus 63.1 +/- 9.9 years) and experienced more of the following: urgent operations (42.4% versus 38.0%), preoperative intra-aortic balloon pump (4.8% versus 1.8%), preoperative cerebrovascular accidents (CVA; 3.1% versus 1.3%) and renal insufficiency (10.5% versus 7.0%). The PP group had higher incidence of early postoperative mortality (2.6% versus 1.5%), CVA (3.1% versus 1.3%), need for dialysis (3.2% versus 2.2%) and longer hospital stay (9.2 +/- 8.3 days versus 8.5 +/- 5.8 days). The incidence of postoperative myocardial infarction and renal dysfunction was similar in both groups (2.0% versus 2.2% and 3.3% versus 3.9% respectively; not significant). Because of the significant difference in preoperative parameters for the PP and NP groups, the following three statistical techniques were used to isolate the effect of perfusion characteristics on operative outcome: multiple regression, propensity score and risk stratification. Multivariate analysis did not find PP to be protective against mortality, morbidity and mortality, and CVA or for the development of postoperative renal dysfunction. When propensity score analysis was applied, the incidence of cardiac morbidity and mortality was strongly associated with the quintile (first quintile 6.7%, fifth quintile 27.0%, P<0.001). Multivariate analysis including quintiles did not find PP to be an independent predictor for mortality or for morbidity and mortality. Risk stratification was performed for age and for preoperative creatinine clearance levels. In all groups, PP did not seem to reduce the incidence of morbidity, morbidity and mortality, or the development of postoperative renal dysfunction. In patients with preoperative renal dysfunction, mean postoperative creatinine levels and the need for dialysis following surgery were similar in the PP and NP groups. CONCLUSION: Pulsatile flow does not appear to offer any clinical benefit over nonpulsatile flow for cardiac surgery patients.

Quality of red blood cells using autotransfusion devices: a comparative analysis.

Cell salvage devices are routinely used to process and wash red blood cells (RBCs) shed during surgical interventions. Although the principle theory of cell saving is the same, the actual process to achieve this is very different from one device to another. The purpose of this study was to compare the quality of washed, concentrated RBC produced by five very different cell-saving devices, specifically the Cobe BRAT 2, Medtronic Sequestra 1000, Haemonetics Cell Saver 5, Medtronic Autolog, and the Fresenius CATS. Reservoir and washed red blood cells were analyzed for hematocrit (Hct), platelets (PLT), leukocytes (WBC), potassium (K+), heparin, plasma-free hemoglobin (PFH), RBC mass recovery and recovery rate. The Haemonetics and BRAT 2 had the highest RBC recovery. All devices adequately removed heparin and potassium. The Medtronic Autolog had the highest removal of platelets and PFH; whereas, the BRAT had the lowest. Although the Autolog had the highest leukocyte removal, leukocytes were not adequately washed out by any of the autotransfusion devices. In conclusion, although all cell-saving devices use the same theory of centrifugation, the actual quality of the washed RBC product differs widely from one device to another.