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Le Groupe d’intérêt en hémostase périopératoire (GIHP) et le Groupe français d’études sur l’hémostase et la thrombose (GFHT), en collaboration avec la Société française d’anesthésie et de réanimation (SFAR) ont fait des propositions de gestion des agents antiplaquettaires (AAP) pour une procédure invasive programmée. Ces propositions ont été discutées et validées par vote ; toutes sauf une ont fait l’objet d’un accord fort. La gestion des AAP dépend de leur indication et de la procédure considérée. Le risque hémorragique lié à la procédure invasive peut être divisé en bas, intermédiaire ou élevé, selon la possibilité ou non de réaliser la procédure sous traitement (sous respectivement bithérapie antiplaquettaire, aspirine en monothérapie ou aucun AAP). Si une interruption des AAP est indiquée avant la procédure, une dernière prise d’aspirine, clopidogrel, ticagrélor et prasugrel 3, 5, 5 et 7 jours avant la procédure est proposée. Le risque thrombotique associé à l’interruption des AAP doit être évalué en fonction de l’indication des AAP. Il est plus élevé chez les patients traités par bithérapie pour un stent coronaire que chez ceux traités par monothérapie pour une prévention cardiovasculaire, un antécédent d’accident vasculaire cérébral ischémique ou une artériopathie oblitérante des membres inférieurs. Ces propositions concernent aussi le rôle potentiel des tests fonctionnels plaquettaires, la gestion des AAP pour l’anesthésie locorégionale, centrale et périphérique, et pour la chirurgie cardiaque coronaire.

Heparin-induced thrombocytopenia (HIT) is a rare, iatrogenic disease characterised by its potential severity, mainly related to thrombosis, and by difficulties regarding its diagnosis and management of affected patients. In 2002, a conference of experts mobilised by the French Society of Anaesthesia and Intensive Care Medicine (Société française d’anesthésie et de réanimation [SFAR]) drafted recommendations for the management of HIT [...]

Background Patient blood management (PBM) interventions aim to improve clinical outcomes by reducing bleeding and transfusion. We assessed whether existing evidence supports the routine use of combinations of these interventions during and after major surgery. Methods Five systematic reviews and a National Institute of Health and Care Excellence health economic review of trials of common PBM interventions enrolling participants of any age undergoing surgery were updated. The last search was on June 1, 2019. Studies in trauma, burns, gastrointestinal haemorrhage, gynaecology, dentistry, or critical care were excluded. The co-primary outcomes were: risk of receiving red cell transfusion and 30-day or hospital all-cause mortality. Treatment effects were estimated using random-effects models and risk ratios (RR) with 95% confidence intervals (CIs). Heterogeneity assessments used I2. Network meta-analyses used a frequentist approach. The protocol was registered prospectively (PROSPERO CRD42018085730). Results Searches identified 393 eligible randomised controlled trials enrolling 54 917 participants. PBM interventions resulted in a reduction in exposure to red cell transfusion (RR=0.60; 95% CI 0.57, 0.63; I2=77%), but had no statistically significant treatment effect on 30-day or hospital mortality (RR=0.93; 95% CI 0.81, 1.07; I2=0%). Treatment effects were consistent across multiple secondary outcomes, sub-groups and sensitivity analyses that considered clinical setting, type of intervention, and trial quality. Network meta-analysis did not demonstrate additive benefits from the use of multiple interventions. No trial demonstrated that PBM was cost-effective. Conclusions In randomised trials, PBM interventions do not have important clinical benefits beyond reducing bleeding and transfusion in people undergoing major surgery.

Patient blood management (PBM) is the timely application of evidence-informed medical and surgical concepts designed to maintain haemoglobin concentration, optimise haemostasis and minimise blood loss in an effort to improve patient outcomes. The aim of this consensus statement is to provide recommendations on the management of anaemia and haematinic deficiencies in pregnancy and in the post-partum period as part of PBM in obstetrics. A multidisciplinary panel of physicians with expertise in obstetrics, anaesthesia, haematology, policymaking and epidemiology was convened by the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA) in collaboration with the International Federation of Gynaecology and Obstetrics (FIGO) and the European Board and College of Obstetrics and Gynaecology (EBCOG). Members of the task force assessed the quantity, quality and consistency of the published evidence and formulated recommendations using the system developed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group. The recommendations in this consensus statement are intended for use by clinical practitioners managing the perinatal care of women in all settings and by policymakers in charge of decision making for the update of clinical practice in health-care establishments. They need to be tailored for application in individual patients or any population after consideration of the values and preferences of both health-care providers and patients, as well as equity issues; explicit assessment of harms and benefits of each recommendation; feasibility including resources, capacity and equipment; and implementability.

Preoperative anaemia is associated with increased postoperative morbidity and mortality. Patient blood management (PBM) is advocated to improve patient outcomes. NATA, the ‘Network for the advancement of patient blood management, haemostasis and thrombosis’, initiated a benchmark project with the aim of providing the basis for educational strategies to implement optimal PBM in participating centres. Prospective, observational study with online data collection in 11 secondary and tertiary care institutions interested in developing PBM. Ten European centres (Austria, Spain, England, Denmark, Belgium, Netherlands, Romania, Greece, France, and Germany) and one Canadian centre participated between January 2010 and June 2011. A total of 2470 patients undergoing total hip (THR) or knee replacement, or coronary artery bypass grafting (CABG), were registered in the study. Data from 2431 records were included in the final analysis. Primary outcome measures were the incidence and volume of red blood cells (RBC) transfused. Logistic regression analysis identified variables independently associated with RBC transfusions. The incidence of transfusion was significantly different between centres for THR (range 7 to 95%), total knee replacement (range 3 to 100%) and CABG (range 20 to 95%). The volume of RBC transfused was significantly different between centres for THR and CABG. The incidence of preoperative anaemia ranged between 3 and 40% and its treatment between 0 and 40%, the latter not being related to the former. Patient characteristics, evolution of haemoglobin concentrations and blood losses were also different between centres. Variables independently associated with RBC transfusion were preoperative haemoglobin concentration, lost volume of RBC and female sex. Implementation of PBM remains extremely variable across centres. The relative importance of factors explaining RBC transfusion differs across institutions, some being patient related whereas others are related to the healthcare process. The results reported confidentially to each centre will allow them to implement tailored measures to improve their PBM strategies.

BACKGROUND Aprotinin has been reapproved for use in Europe and in Canada. We sought to determine if its reintroduction was still pertinent given the widespread administration of tranexamic acid, another antifibrinolytic shown to reduce bleeding and transfusions. STUDY DESIGN AND METHODS After institutional review board approval, we examined the cardiac surgery database (2012-2015; 3322 patients). Major transfusion was defined as 4 or more red blood cell units. A stratified multivariate logistic regression analysis identified predictors of major transfusion; 1064 patients were matched by propensity score to compare outcomes of patients with or without major transfusion. RESULTS Cardiopulmonary bypass (CPB) was used in 2342 patients; 98.9% received tranexamic acid versus 15.2% (149/980) in off-pump coronary artery bypass graft patients. Major transfusion was required in 758 patients (23%). Age, low body mass index, low preoperative hemoglobin or platelet count, recent use of P2Y12 receptor blockers, chronic kidney disease, NYHA functional class, left ventricular ejection fraction of less than 30%, prior cardiac surgery, urgency, type of cardiac surgery, and duration of CPB were all independent predictors of major transfusions (all p

No clear recommendations exist regarding the optimal dosing of unfractionated heparin (UFH) during vascular surgery. Moreover, little is known about the effect of the UFH bolus downstream of the arterial clamp, where stasis and inflammation can possibly alter the anticoagulation obtained.The aim of our prospective observational study was to assess anticoagulation below the arterial clamp and its clinical impact on the quality of revascularization. Thirty-six patients American Society of Anaesthesiologists physical status (ASA) grade I-III undergoing open revascularization surgeries were included. A baseline activated coagulation time (ACT) was obtained. Thirty minutes after a single bolus of 5,000 units of UFH, we measured an upstream ACT via a radial arterial catheter and an ACT below the arterial clamp via surgeon sampling. The quality of revascularization was assessed with preoperative and postoperative ankle-brachial and toe-brachial indexes (TBIs).The upstream postheparin ACT was significantly higher than the downstream postheparin ACT, with a mean difference of 24.3 sec (P 0.0001). In 7 patients, the downstream ACT was lower than the baseline ACT. The upstream and downstream heparin concentrations were similar. There was no relationship between the downstream ACT and either ankle-brachial index improvement (28 patients, P = 0.51) or TBI improvement (27 patients, P = 0.21).Our study demonstrates a significant difference between the ACT above and below the arterial clamp without any clinical impact of this possibly insufficient anticoagulation. Further investigations are warranted to determine the optimal dose of UFH in vascular surgery.Clinicaltrials.gov, NCT02477072.

Resume Tres peu d’etudes controlees ont ete publiees sur les benefices et les risques de la transfusion erythrocytaire et des produits sanguins hemostatiques, que ce soit en chirurgie programmee ou lors de transfusion massive. Les etudes controlees concernant la transfusion erythrocytaire en chirurgie programmee, publiees depuis les annees 1980, suggerent que la morbidite et la mortalite ne sont pas differentes lorsqu’une strategie restrictive (seuil transfusionnel entre 7 et 8 g/dL) ou une strategie liberale (seuil de 10 g/dL) sont appliquees. Pour la transfusion massive, il faut distinguer le contexte chirurgical ou la situation est controlee (normovolemie, normothermie, prise en charge precoce, etc.) et le traumatisme majeur ou la situation ne l’est pas (choc, hypothermie, coagulopathie aigue, etc.). Aucune etude controlee ne peut nous guider dans cette derniere situation. L’utilisation de ratios fixes et eleves de concentres de produits hemostatiques/globules rouges ne s’appuie pas sur des donnees probantes mais pourrait etre benefique dans des circonstances plutot exceptionnelles en traumatologie civile. La plupart des recommandations transfusionnelles publiees a ce jour sont limitees par le manque de donnees probantes et refletent notre ignorance de la question. Nous devons poursuivre des etudes cliniques de haut niveau afin de determiner les strategies transfusionnelles optimales chez differentes populations de malades.

Few randomized controlled studies, the only trial design where causality can be established between an intervention and the benefits or harms thereof, have been published on the benefits and risks of a restrictive vs a liberal transfusion strategy. We review the 19 controlled studies on erythrocyte transfusion thresholds published since the eighties. These studies suggest that, overall, morbidity (including cardiac morbidity) and mortality, along with hemodynamic, respiratory and oxygen transport variables, are similar when a restrictive transfusion strategy (transfusion threshold between 7 and 8 g/dL) or a liberal strategy (transfusion threshold of 10 g/dL) are used. In fact, a restrictive strategy can even be associated with a number of benefits. The relevance of a higher transfusion threshold in view of avoiding morbidity in patients presenting a cardiovascular risk is unlikely, at least uncertain. Finally, anaemia has little or no impact on functional recovery and on quality of life, whether in the immediate or late postoperative period. It is clear that a restrictive strategy is associated with a reduced exposure to red cell transfusions, allowing a reduction in transfusion-related adverse events. Thus, all red cell transfusions must be tailored to the patient's needs, at the time the need prevails. In conclusion, most recommendations on transfusion practice are limited by the lack of evidence-based data and reveal our ignorance on the topic. High quality clinical trials in different patient populations must become available in order to determine optimal transfusion practices. Since then, a restrictive strategy aiming for a moderately anaemic threshold (7-8 g/dL) is appropriate under most circumstances.

BACKGROUND: Clinicians have adopted a restrictive transfusion threshold (75-80 g/L) after major orthopedic surgery. Anemia may be associated with a decrease in postoperative vigor. We hypothesize that, in these patients, a threshold hemoglobin (Hb) concentration exists below which functional recovery and quality of life (QoL) become difficult. STUDY DESIGN AND METHODS: A prospective, observational cohort study in 305 patients 60 years or older undergoing a total hip or knee arthroplasty was conducted. Major outcome variables were distance walked in 6 minutes (6MWT), score on the Borg Scale for perception of effort, maximal dominant hand strength, and Short Form 36 (SF-36) QoL assessment in the preoperative and early postoperative periods. Patients were categorized according to their Hb level the day of the postoperative 6MWT (≤80, 81-90, 91-100, and >100 g/L). RESULTS: There was no difference between Hb groups in the decrease of the distance walked preoperatively versus postoperatively. For both moments of observation, the 6MWT was not significantly different between Hb groups (p = 0.190). Similar results were found with perception of effort, maximal dominant hand strength, and SF-36 QoL assessment scores. In a regression model, the decrease in Hb concentration could explain only 1.9% of the total variation observed in the 6MWT (p = 0.008). CONCLUSION: Moderate anemia is not associated with an impaired functional recovery or QoL in the immediate postoperative period after major arthroplasties. Further studies will be required to determine the long-term consequences of a restrictive transfusion strategy in these patients.

BACKGROUND: The indications for red blood cell (RBC) transfusions remain unclear despite published guidelines. Our hypothesis was that the transfusion practice varies inside the Centre hospitalier de l'Universite de Montreal (CHUM). STUDY DESIGN AND METHODS: A total of 701 charts of patients who underwent a knee or hip arthroplasty or prosthesis revision in three hospitals of the CHUM were reviewed. Demography, hemoglobin (Hb) concentrations, details on transfusions, and postoperative adverse events (AEs) were collected up until discharge. The primary outcome was the presence or absence of RBC transfusion. Secondary outcomes were the nadir Hb, number of units transfused, discharge Hb, blood losses, and postoperative AEs. RESULTS: The rate of postoperative transfusion was 29%. We found no significant difference between odds ratios of each site for sex, coronary artery disease, chronic heart failure, type of procedure, American Society of Anesthesiologists physical status, weight, height, body mass index, body surface area, and estimated blood volume. Overall, patients were transfused at a Hb between 75 and 80 g/L. Eighty-five percent of postoperative transfusions could be predicted using only nadir Hb and adding patient characteristics did not substantially improve the model (86.1%). Discharge Hb was below 100 g/L in 66% of patients. CONCLUSIONS: There was no difference among hospitals regarding the way RBC transfusions are used. Our data suggest that physicians mainly based their decision to transfuse on a single variable, the Hb concentration, with the use of a restrictive strategy. Future trials should focus on the optimal transfusion trigger to adopt in major orthopedic surgery.

Excessive/abnormal bleeding is a common problem aftercardiac surgery with cardiopulmonary bypass (CPB).Excessive bleeding results in increased transfusionrequirements, both for red blood cell concentrates(packed red blood cells – PRBCs) and for hemostaticblood products and, in the most severe cases, may requiresurgical reexploration of the mediastinum [1]. The inci-dence of excessive bleeding after CPB surgery variesaccording to its definition and to the center where surgeryis conducted, ranging from 11 [2] to 29% [1]. Surgicalreoperation of the mediastinum for excessive bleeding isnecessary in up to 14.3% of cases, the incidence ofreexploration being the least for coronary artery surgery,intermediate for valve surgery and the most important forcomplex operations [1]. Although the cause-to-effectrelationship of transfusion of allogeneic blood products(ABPs) to postoperative morbidity and mortality has notbeen demonstrated clearly, several articles suggest thatthis may well be the case, particularly in cardiac surgicalpatients [3–10].Endogenous activated factor VII plays a crucial role inthe coagulation process. The clotting drug NovoSeven[coagulationfactorVIIa(recombinant);NovoNordiskA/S,Bagsvaerd, Denmark] is structurally nearly identical toendogenous factor VIIa and produced by recombinationfrom a baby hamster kidney cell line. Supraphysiologicconcentrations of activated factor VII are achieved by theadministration of pharmacological doses of recombinantactivated factor VII (rFVIIa). rFVIIa plays a central role incoagulation according to the newer, cell-based concepts ofcoagulation that have emerged recently [11]. To generatethrombin, rFVIIa needs either tissue factor or activatedplatelets (tissue factor-independent generation).During initiation of coagulation, tissue factor exposed onthe subendothelium forms a complex with circulatingfactor VIIa. The tissue factor–factor VIIa complex acti-vates factor X and leads to the generation of a smallquantity of thrombin. This small quantity of thrombinactivates platelets and cofactors, ‘priming’ the system forthe subsequent generation of large amounts of thrombin.Factor IX, also activated during the initiation phase, acts

BACKGROUND: Aprotinin, a non-specific serine protease inhibitor, has been used for two decades to reduce perioperative blood loss and the risk for allogeneic transfusion in cardiac surgery. This study evaluated the effects of aprotinin on outcome (mortality, cardiac events, renal failure, and cerebrovascular events) in such patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Data were obtained in patients who received a strict blood conservation protocol: no antifibrinolytic therapy when at low risk (n = 854) and aprotinin (n = 1210) when at high risk for blood transfusion. Relative risk of different pre- and intra-operative variables was calculated for the different outcome variables. Backward stepwise logistic regression analysis was used to identify the independent risk factors associated with the different outcome variables. Statistical significance was accepted at P 1.5 mg dl(-1), urgent, and redo surgery were the independent variables associated with postoperative haemodialysis. Age > 70 yr was identified as the only independent variable associated with neurologic dysfunction. CONCLUSIONS: In the present study, patients receiving aprotinin as part of a strict blood conservation strategy represent a population at high risk for postoperative complications. For the outcome variables studied, aprotinin administration was not identified as an independent risk factor

Aprotinin has been reapproved for use in Europe and in Canada. We sought to determine if its reintroduction was still pertinent given the widespread administration of tranexamic acid, another antifibrinolytic shown to reduce bleeding and transfusions.After institutional review board approval, we examined the cardiac surgery database (2012-2015; 3322 patients). Major transfusion was defined as 4 or more red blood cell units. A stratified multivariate logistic regression analysis identified predictors of major transfusion; 1064 patients were matched by propensity score to compare outcomes of patients with or without major transfusion.Cardiopulmonary bypass (CPB) was used in 2342 patients; 98.9% received tranexamic acid versus 15.2% (149/980) in off-pump coronary artery bypass graft patients. Major transfusion was required in 758 patients (23%). Age, low body mass index, low preoperative hemoglobin or platelet count, recent use of P2Y12 receptor blockers, chronic kidney disease, NYHA functional class, left ventricular ejection fraction of less than 30%, prior cardiac surgery, urgency, type of cardiac surgery, and duration of CPB were all independent predictors of major transfusions (all p 0.05). Major transfusion was associated with a more than threefold increase in mortality (7.1% vs. 2.1%; p 0.001) and increases in major adverse events (p 0.001).Despite the use of tranexamic acid, 23% of cardiac surgery patients require a major transfusion. We identified predictors of major transfusion and showed that major transfusion is associated with important increases in mortality and morbidity. We conclude that there is still a need for an effective and safe blood-sparing drug in cardiac surgery.

Revoir brievement, chez les patients qui doivent etre operes, les risques associes aux inhibiteurs plaquettaires disponibles et presenter les principes qui devraient guider ľevaluation de ces risques et la facon de les eviter. Une revue descriptive de documents medicaux courants en anglais et en francais. Les inhibiteurs plaquettaires [surtout ľacide acetylsalicylique, le clopidogrel et les inhibiteurs de la glycoproteine (GP) IIb/IIIa] sont de plus en plus utilises pour prevenir la thrombose arterielle. Les cliniciens sont confrontes au risque hemorragique lie a la continuation des inhibiteurs plaquettaires tout au long de ľoperation ou, inversement, au risque thrombotique lie a leur interruption. La plupart des experts recommandent la chirurgie tout en maintenant ľacide acetylsalicylique pour la plupart des operations vasculaires et les autres contextes ou le risque ďhemorragie a ete prouve faible, ou pourrait ľetre. En general, on recommande ďinterrompre le clopidogrel cinq jours avant ľoperation pour permettre la regeneration du pool plaquettaire. Cette approche a ete associee a des incidents thrombotiques chez des patients en attente ďune revascularisation myocardique urgente. Dans ce contexte, ľaprotinine peut reduire les pertes sanguines et les besoins de transfusion. Le retrait des inhibiteurs competitifs de la GPIIb/IIIa, au debut de ľoperation, diminue le risque de saignement, ce qui est moins le cas de ľabciximab a cause de sa forte liaison aux recepteurs plaquettaires. Les plaquettes doivent etre transfusees preventivement, mais seulement aux rares patients dont le saignement anormal semble relie a ľeffet persistant du traitement antiplaquettaire. Malheureusement, les donnees sont rares concernant le traitement des patients traites aux inhibiteurs plaquettaires qui ne doivent etre operes, surtout en chirurgie non cardiovasculaire. La prise en charge de ces patients necessite ďautres etudes cliniques.

Very few randomized controlled trials on the benefits of red blood cell (RBC) transfusions in humans have been published. Consequently, most clinical practice guidelines are based on expert opinion, animal studies and the limited human trials available. In the absence of definitive outcome studies, numerous theoretical arguments have been put forward either to support or to condone the classic transfusion threshold of 10 g/dL. However, the limited data available from randomized controlled trials suggest that a restrictive transfusion strategy (transfusion threshold between 7 and 8 g/dL) is associated with decreased transfusion requirements, that overall morbidity (including cardiac morbidity) and mortality, hemodynamic, pulmonary and oxygen transport variables are not different between restrictive and liberal transfusion strategies and, finally, that a restrictive transfusion strategy is not associated with increased adverse outcomes. In fact, a restrictive strategy may be associated with decreased adverse outcomes in younger and less sick critical care patients. Since transfusions are administered to correct inadequate oxygen delivery, whether global or regional, reliable monitors of tissue oxygenation will be required to study the benefits (or lack thereof) of RBC transfusions. The quest for a universal transfusion trigger, the holy grail of transfusion medicine, must be abandoned. All RBC transfusions must be tailored to the patient's needs, at the moment the need arises. In conclusion, most published recommendations are appropriate but their conclusions are limited, as they are commensurate with existing knowledge. Reliable monitors to guide transfusion therapy and well conducted trials to determine optimal transfusion strategies are required.

SUMMARy Fresh frozen plasma (FFP) is the liquid portion of one unit of human blood that contains the labile and stable components of the coagulation, fibrinolytic and complement systems, as well as the proteins that maintain oncotic pressure and modulate immunity. The clinician must remember that a unit of single-donor allogeneic plasma is a heterogeneous solution of proteins. Infusion of FFP normalizes abnormal tests efficaciously in patients with hereditary coagulopathies. However, its benefit in the treatment of excessive bleeding remains unclear and variable. In clinical practice, indication to transfuse FFP is based on a double threshold: a combination of abnormal coagulation tests plus excessive bleedings. FFP is not the first-line option in the prevention of hemorrhage and in emergency reversal of oral anticoagulation for life-threatening complications.

SUMMARY Coagulopathy associated with massive transfusion remains an important clinical problem. In this paper, the objectives of the authors are two-fold: to identify the causes of coagulopathy in massively transfused adult and previously hemostatically competent patients and to differentiate between the elective surgical setting and trauma, in order to recommend the most appropriate treatment strategies. A MEDLINE search was conducted for published articles on massive transfusion, using the terms “transfusion,”“trauma,”“surgery,”“coagulopathy,” and “hemostatic defects.” Articles were organized and reviewed by date of publication in order to better understand the evolution of our thinking on massive transfusion and coagulopathy. Coagulopathy associated with massive transfusion is an intricate, multifactorial, and multicellular event. In trauma patients, tissue trauma and anoxia, shock, and hypothermia contribute to the development of disseminated intravascular coagulation and microvascular bleeding. In patients undergoing elective surgery, a decrease in fibrinogen concentration is observed initially while thrombocytopenia is a late occurrence. Critically low levels of coagulation factors were seldom reported when whole blood was in common use. With the use of packed red cells, however, dilution or consumption of coagulation factors has become a significant issue requiring specific treatment with, primarily, fresh frozen plasma. Maintaining a normal body temperature is a simple and effective strategy to improve hemostasis during massive transfusion. Red cells play an important role and hematocrit levels as high as 35 to 36% may be required to sustain the process. The administration of platelets and/or fresh frozen plasma should be based on clinical judgment and coagulation testing results, and their use restricted to the treatment of clinical coagulopathies.

OBJECTIVES: In paediatric cardiac surgery, red blood cell (RBC) transfusions are given to treat haemorrhage or to increase oxygen delivery (therapeutic transfusion). Sometimes, RBCs are added to the prime solution to avoid a too low haematocrit on bypass (CPB-driven transfusion). Our study investigated whether the reason for RBC transfusion might affect severe postoperative morbidity or mortality. METHODS: This retrospective cohort study was conducted in a tertiary care level, children’s hospital. The charts of all patients admitted between 2006 and 2009 were reviewed. Among transfused patients, children receiving a therapeutic transfusion were compared with those receiving a CPB-driven transfusion. The primary outcome was severe postoperative morbidity or mortality. Statistically significant variables founded with univariate analysis were incorporated in the multivariable logistic regression analysis to build a model that predicts severe postoperative morbidity or mortality. This model was then adjusted for clinically relevant variables that may interfere with ‘indication for transfusion’. RESULTS: One hundred and one (48%) patients in the therapeutic and 92 (26%) patients in the CPB-driven transfusion group developed severe postoperative morbidity or died (P< 0.001). A multivariable logistic regression showed that weight, ASA, calculated blood loss, intraoperative fluid balance, duration of CPB time and the indication group for transfusion [1.64 (1.03–2.62); P= 0.039] were independent risk factors for severe postoperative morbidity or mortality. The indication group for transfusion remained significant [2.0 (1.16–3.45); P= 0.013] after adjustment for significant predictors of indication for transfusion. Number of patients with infections, or neurological deficit, and length of mechanical ventilation, PICU and hospital length of stay, were significantly higher in the therapeutic compared with the CPB-driven transfusion group one. CONCLUSIONS: The indication group for transfusion has an impact on the occurrence of severe postoperative morbidity or mortality in children undergoing cardiac surgery.

To develop an instrument to measure patients’ perceptions of the services provided by anesthesiologists, an important indicator of quality for which little information is available. The scale of patients’ perceptions of cardiac anesthesia services (SOPPCAS) is composed of 17 Likert-type and sociodemographic questions. Data collection was conducted on T-1 (fourth postoperative day) and T-2 (15 days postoperatively). In addition, we employed the Marlow-Crowne scale and a short form of the Psychological Symptoms Index to verify the influence of social desirability and psychological distress respectively. Data analysis included a principal component analysis (PCA). One hundred seventy patients answered the questionnaires at T-1 and 133 patients at T-2. Cronbach alpha of the SOPPCAS was 0.58. PCA revealed four perioperative factors: patient/anesthesiologist interactions, preoccupations related to anesthesia, experience with anesthesia and pain management. Global mean satisfaction was 4.45 ± 0.64 (maximum score 6.0). Main items related to satisfaction were: satisfaction with premedication, empathy from anesthesiologists, pain management. Main items related to dissatisfaction were: lack of information on blood transfusion and recall of endotracheal intubation. A score of 14/20 was obtained for social desirability. Social desirability did not influence the construct of the SOPPCAS. We developed, using rigorous methods, an instrument to measure patients’ perceptions of the quality of cardiac anesthesia services. Global mean satisfaction with anesthesia services was moderately high contrary to previous studies where it was high. Finally, the SOPPCAS should allow anesthesiologists to improve the quality of the care they provide.

Malgre une utilisation courante, la reproductibilite des mesures du Thromboelastographe® (TEG), du Sonoclot® (SCT), et de l’Hemochron® mesurant le temps de coagulation active avec celite ou kaolin (ACT-C et ACT-K), a ete peu etudiee dans les conditions reelles d’utilisation. La presente etude evalue la reproductibilite de ces mesures, et la possibilite de substituer l’ACT-C par un des autres tests. Les echantillons sanguins ont ete preleves chez 20 volontaires et 21 patients devant subir une revascularisation myocardique, et analyses dans deux canaux du TEG, deux SCT et quatre Hemochron®. Les traces du TEG et du SCT ont ete analyses respectivement par ordinateur et par un observateur experimente. Le pourcentage de variation (V %) pour chaque variable et l’interchangeabilite de l’ACT-K et du SCT avec l’ACT-C ont ete evalues. Les V % de l’ACT-C et de l’ACT-K varient respectivement de 5,6 % a 10,8 % et de 6,7 % a 12,4 % selon les conditions. Les V % du TEG et du SCT varient respectivement de 3,1 % a 9,5 % et de 5,8 % a 33,6 %, selon les conditions et les parametres etudies. Aucun instrument ne peut se substituer a l’ACT-C en presence d’heparine et durant la circulation extracorporelle (CEC). Chez les volontaires et les malades non heparinises, l’ACT-C et l’ACT-K sont interchangeables. Dans des conditions reelles d’utilisation en chirurgie cardiaque, les mesures les plus reproductibles sont obtenues, dans un ordre decroissant, avec le TEG, l’Hemochron puis le SCT Les resultats des differents tests ne sont pas interchangeables chez le malade durant la CEC.

M ORE than 13 million units of red blood cells (RBC) are collected in the United States and over 1 1 million units are transfused to 3.4 million patients annually. It is estimated that 60 70% of these RBC units are transfused in the perioperative period. Such considerable numbers are in sharp contrast with the little knowledge we have on the true benefits of ery throcyte transfusions. In this refresher course lecture, we will discuss the risks of anemia and the benefits of RBC transfusions in the perioperative context. For a more detailed and formal review of the literature, the reader is referred to a recently published text by the same authors. 1 Conceptually, the risk/benefit ratio of erythrocyte transfusions must take three factors into account: 1) the risks secondary to anemia which depend, in turn, on the patient's capacity to compensate for it; 2) the capacity of allogeneic RBC to correct these risks, a consideration which is all too often assumed but has not been well demonstrated; 3) the risks of transfusions themselves. While the infectious risks of blood products, specially HIV, have brought about a major reconsideration of the way we should be administering transfusions, the risks associated with the immunomodulating effects of blood products, as well as the "classic" complications (volume overload, ABO incompatibility, etc.) of RBC transfusions should be kept in mind. Given the inherent complexity of this risk/benefit analysis, it becomes rapidly apparent that any attempt to define a universal "transfusion trigger" is overly simplistic and unrealistic from a scientific standpoint. The analogy with a "fever trigger" illustrates why the attempt to define a "transfusion trigger" is doomed to fail clinically. Attempting to define a "fever trigger", i.e., the fixed body temperature above which penicillin should be administered would, nowadays, be consid ered absurd. Yet, this is the approach adopted by sever al when transfusing RBC. Erythrocytes (penicillin) are administered for anemia (fever) without knowing if the underlying disease will respond to the elected therapeu tic approach. Adopting a universal "fever trigger" would certainly cure a few individuals, but would need lessly expose a considerable number of patients to peni cillin and result in a significant number of untoward events, allergic or other. Erythrocyte transfusions: the arguments In contrast with the paucity of objective data on the risks of anemia or the benefits of RBC transfusions, several arguments have been put forward either to support or to condone erythrocyte transfusions in the perioperative period. RaHonale in favour of IP~BC transfusions to maintain a high hemoglobin concentvaHon Classically, several arguments have supported the use of RBC transfusions to maintain a high hemoglobin concentration ([Hb]" above 100 g.L 1). • Transfusions are thought to be safer than ever. While this is true in part, the growing concern in Europe with new variant Creutzfeldt Jakob disease illustrates how fragile the situation really is. 2 • Increased 0 2 delivery may improve survival in the intensive care setting. Yet, it remains unclear if the best way to achieve increased 02 delivery is by increasing cardiac output or by increasing [Hb]. • Patients with cardiovascular disease may not be able to compensate for anemia and a high [Hb] will decrease the risk of morbidity and mortality. • Similarly, advanced age, disease and drugs will diminish the adaptation to anemia and a high [Hb] will decrease the risk of morbidity and mortality. • A high [Hb] is required for optimal hemostasis. The contribution of RBC to coagulation is impor tant and all too often overlooked. • A high [Hb] will restore peripheral blood volume and decrease the risks associated with under perfu sion of the gastrointestinal tract. • A high [Hb] will improve the margin of safety, should further bleeding occur. • Finally, a high [Hb] is associated with improved From the Departments of Anesthesiology, Centre Hospitalier de l'Universit6 de Montr6al and Institut de CaJdiologie de Montr6al, Universit6 de Montr6al, Montreal, Quebec, Canada. Address correspondence to'. Dr. Jean Francois Hardy, CHUM HOtel Dieu de Montreal, Pavillon de Bouillon, local 6 521, 3840 me St Urbain, Montreal, Quebec, Canada H2W 1T8. Phone: 514 8908000, ext. 15578; Fax: 514 412 7143; E mail: jean francois.hardy@umontreal.ca CAN J ANESTH 2001 / 48:6 / pp R1 R7

Veno-arterial and regional differences of the partial pressure in CO2 (deltaPCO2), may be used as index to evaluate the adequacy of the cardiac output to the oxygen consumption. To determine the incidence of elevated deltaPCO2 and its relationship with difficult separation from bypass (DSB) in patients undergoing cardiac surgery, we conducted a prospective observational cohort study.Data were collected from 58 consecutive patients undergoing various cardiac operations requiring cardiopulmonary bypass (CPB). During the procedure, arterial and venous blood gases and lactate were sampled. Blood was drawn after induction of anesthesia, during bypass and at the closure of the chest wall. Difficult separation from bypass was defined as a systolic arterial pressure80 mmHg, and diastolic pulmonary artery pressure15 mmHg during progressive separation from CPB with inotropic or mechanical support of cardiac function, or hemodynamic instability resulting in reintroduction of extra-corporeal circulation or insertion of an intra-aortic balloon pump.In our study, 65% of the samples were associated with elevated deltaPCO2 (6 mmHg). Variables associated with difficult weaning were LVEF; duration of bypass and aortic cross-clamping, pre-bypass deltaPCO2 and in-bypass lactate values (P0.05). Multivariable analysis identified the pre-bypass deltaPCO2 and the duration of bypass as predictors of DSB.Elevated deltaPCO2 is frequently observed during cardiac surgery and values obtained before bypass were associated with DSB. The deltaPCO2 gradients could be used as marker of the adequacy of tissue perfusion during cardiac surgery.

SUMMARY Overall, anemia increases the risk of mortality only when hemoglobin concentration (Hb) falls below 50 g/L. This effect is magnified by blood losses and cardiovascular disease. No evidence supports a beneficial effect of transfusions in less sick patients and those without cardiovascular disease when Hb is above 70 g/L. Especially in areas of the world where blood transmissible diseases are endemic, the considerable risks of HIV infection nearly always outweigh the benefits of transfusion, even in severely anemic patients. Definitive evidence that minimal Hb greater than 90–100 g/L in patients with cardiovascular disease prevents cardiac morbidity is lacking. Transfusions to improve oxygen transport are definitely not indicated in critically ill adults. Transfusions may be deleterious in patients with several, non-cardiovascular diagnoses. Conversely, in anemic shock, transfusions allow early withdrawal of supportive therapy. Erythrocyte transfusions improve hemostasis and reduce perioperative complications in patients with sickle cell disease.

Background . Uncontrolled clinical experience at our institution suggested that low-dose aprotinin could control excessive bleeding after cardiopulmonary bypass (CPB). A randomized clinical trial was conducted to determine the efficacy of low-dose aprotinin in the treatment of hemorrhage after cardiac surgery. Methods . One hundred seventy-one patients undergoing cardiac surgery with CPB were included. Forty-four patients (26%) bled significantly in the intensive care unit (>100 mL/h) and received either aprotinin (200,000 KIU bolus + 100,000 KIU/h for 8 hours) or placebo in addition to our standard management of excessive bleeding. Results . Median bleeding before study drug administration was not different between aprotinin (200 mL) and placebo (212.5 mL) groups. Bleeding decreased significantly with time and similarly in both groups. Ninety-five percent of patients required transfusions in both groups. Median blood products transfused were 13 and 8 units per patient in the aprotinin and placebo groups respectively ( p = NS). Conclusions . Routine administration of low-dose aprotinin as part of the treatment protocol to control hemorrhage after CPB does not reduce bleeding or transfusion requirements and, therefore, cannot be recommended.

Introduction L’efficacite de l’acide tranexamique (AT) en chirurgie majeure du rachis n’a pas ete clairement demontree chez l’adulte. De faibles doses d’AT diminuent le saignement (un outcome intermediaire) mais pas la transfusion [1] . Par contre, de hautes doses d’AT ont demontre leur efficacite chez les enfants [2] et en chirurgie orthopedique majeure [3] . Nous avons evalue les effets de hautes doses d’AT sur les besoins transfusionnels en chirurgie majeure du rachis. Materiel et methodes Notre etude randomisee, en double insu et controlee par placebo a ete approuvee par le comite d’ethique et de la recherche. Quatre-vingt-dix-neuf patients beneficiant d’une chirurgie majeure du rachis a fort risque hemorragique (carcinologique/multi-niveaux) ont consenti a y participer. Les patients ont recu l’AT (bolus 30 mg/kg a l’induction + perfusion 16 mg/kg/h) ou un volume egal de normal salin (NS) jusqu’a 6 h apres la fin de la chirurgie. Les outcomes primaires etaient l’incidence de transfusion et, chez les patients transfuses, le nombre d’unites transfusees. Un TEG (controle et q. 2 h) a ete obtenu chez les 30 premiers malades. Resultats Un patient a ete exclu du groupe AT, la chirurgie comprenant une resection pulmonaire et de la cage thoracique. L’incidence de transfusions a ete la meme dans les deux groupes (AT 53 % vs NS 57 %) alors que, chez les patients transfuses, les besoins transfusionnels etaient diminues ( Tableau 1 ). Les saignements postoperatoires etaient diminues dans le groupe AT (265 mL (0, 505) vs 600 mL (340, 865) ; p = 0,0002). A la fin de l’intervention les D-dimeres etaient abaisses dans le groupe AT (340 mcg/L (217, 655) vs le groupe NS 3730 mcg/L (2500, 5110) ; p Discussion Nous avons montre que, comme en chirurgie cardiaque, (Anesthesiology 2014;120:590) de hautes doses d’AT ne diminuent pas l’incidence des transfusions alors qu’elles diminuent efficacement les besoins transfusionnels et les pertes sanguines postoperatoires. L’AT s’est revele securitaire dans notre (petit) collectif de patients.

Objective Polytraumatized patients present with defects of haemostasis that manifest clinically either by haemorrhage and/or thrombosis. During the initial, as well as during the later phases of treatment, clinicians should take into account the most recent developments in the understanding, in the evaluation of the risk, and in the prevention of haemorrhagic and thrombotic complications.

Objectives. The purpose of this study was to determine the impact of changes in flow on aortic valve area (AVA) as measured by the Gorlin formula and transesophageal echocardiographic (TEE) planimetry. Background. The meaning of flow-related changes in AVA calculations using the Gorlin formula in patients with aortic stenosis remains controversial. It has been suggested that flow dependence of the calculated area could be due to a true widening of the orifice as flow increases or to a disproportionate flow dependence of the formula itself. Alternatively, anatomic AVA can be measured by direct planimetry of the valve orifice with TEE. Methods. Simultaneous measurement of the planimetered and Gorlin valve area was performed intraoperatively under different hemodynamic conditions in 11 patients. Left ventricular and ascending aortic pressures were measured simultaneously after transventricular and aortic punctures. Changes in flow were induced by dobutamine infusion. Using multiplane TEE, AVA was planimetered at the level of the leaflet tips in the short-axis view. Results. Overall, cardiac output, stroke volume and transvalvular volume flow rate ranged from 2.5 to 7.3 liters/min, from 43 to 86 ml and from 102 to 306 ml/min, respectively. During dobutamine infusion, cardiac output increased by 42% and mean aortic valve gradient by 54%. When minimal flow was compared with maximal flow, the Gorlin area varied from (mean ± SD) 0.44 ± 0.12 to 0.60 ± 0.14 cm2(p Conclusions. By simultaneous determination of Gorlin formula and TEE planimetry valve areas, we showed that acute changes in transvalvular volume flow substantially altered valve area calculated by the Gorlin formula but did not result in significant alterations of the anatomic valve area in aortic stenosis. These results suggest that the flow-related variation in the Gorlin AVA is due to a disproportionate flow dependence of the formula itself and not a true change in valve area. (J Am Coll Cardiol 1997;29:1296–302)

Background and aim of the study: High-dose aprotinin is an effective but costly method to reduce transfusions after cardiopulmonary bypass (CPB). Very low doses of aprotinin have been shown to be effective in primary cardiac surgery, but not in patients undergoing procedures associated with the greatest usage of allogeneic blood products after CPB. We evaluated the efficacy of ultra-low-dose aprotinin in this patient population. Methods: Aprotinin 1 million KIU or placebo was added to the priming solution of the CPB circuit of 52 patients undergoing a reoperation and/or a complex surgical procedure. Dryness of operative field, hemoglobin concentrations, coagulation parameters, chest drainage, and transfusion requirements were compared. Results: Total chest drainage was not different between groups, but fewer patients in the aprotinin group required additional protamine postoperatively (35% vs 69% for controls, p = 0.03) and fewer received fresh frozen plasma (FFP; 19% vs 46% for controls, p = 0.04). Red cell transfusion was smaller in the aprotinin group compared to placebo (median 4 and 2 units, respectively, p = 0.04). Transfusion of FFP, platelets, cryoprecipitates was not different between groups. Total number of units transfused tended to be reduced in the aprotinin group compared to control (median 2 and 7 units, respectively, p = 0.06). Conclusions: Prophylactic administration of ultra-low-dose aprotinin reduced transfusions in patients undergoing repeat operations or complex procedures. Aprotinin could be used in a more economical manner, even in this patient population at high-risk of receiving allogeneic blood products.

Background . Various strategies have been proposed to decrease bleeding and allogeneic transfusion requirements during and after cardiac operations. This article attempts to document the usefulness, or lack thereof, of the nonpharmacologic methods available in clinical practice. Methods . Blood conservation methods were reviewed in chronologic order, as they become available to patients during the perisurgical period. The literature in support of or against each strategy was reexamined critically. Results . Avoidance of preoperative anemia and adherence to published guidelines for the practice of transfusion are of paramount importance. Intraoperatively, tolerance of low hemoglobin concentrations and use of autologous blood (predonated or harvested before bypass) will reduce allogeneic transfusions. The usefulness of plateletpheresis and retransfusion of shed mediastinal fluid remains controversial. Intraoperatively and postoperatively, maintenance of normothermia contributes to improved hemostasis. Conclusions . Several approaches have been shown to be effective. An efficient combination of methods can reduce, and sometimes abolish, the need for allogeneic blood products after cardiac operations, inasmuch as all those involved in the care of cardiac surgical patients adhere thoughtfully to existing transfusion guidelines.

Background . Performance of a majority of cardiac surgical procedures requires the use of extracorporeal circulation. Contact of the patients' blood with the nonendothelial surface of the cardiopulmonary bypass circuit is responsible for several, potentially harmful systemic reactions. Methods . The patients' response to extracorporeal circulation is reviewed briefly. The interactions between patient and circuit are discussed not only as they relate to blood-material contact, but also from a mechanical and rheologic standpoint. The theoretic benefits of the newer, more hemocompatible materials are presented, along with a review of published clinical experience with heparinized cardiopulmonary bypass circuits. Results . The response to extracorporeal circulation extends far beyond a simple derangement of hemostasis. This inflammatory response is strongly influenced by the rheologic design of the circuit and by the physical and chemical properties of the surface. Heparinized circuits decrease inflammation, but the clinical benefits of this reduction remain unclear, except for extended cardiopulmonary support. The safe use of these circuits requires full heparinization and does not reduce allogeneic transfusions. Conclusions . Clinicians are still in the search of the ideal material and the ideal extracorporeal circuit design. Newer, heparinized materials offer real but limited clinical benefits.

Le transport d'oxyg~ne depuis l'atmosph~re jusqu'~ la cellule r6sulte de deux m6canismes de convection et de deux processus de diffusion. La diff6rence des pressions partielles en oxyg6ne (02) g6n6r6e au cours de son cheminement dans l'organisme est le moteur qui en maintient l'accessibilit6 cellulaire. La capacit6 r6siduelle fonctionnelle pulmonaire e.t l'h6moglobine (Hb) constituent les deux r6servoirs principaux qui alimentent ce moteur. Afin que cette r6serve soit disponible, l 'Hb doit non seulement transporter l'oxyg~ne mais aussi, et surtout, avoir la capacit6 de le lib6rer lorsque soumise aux conditions r6gnant dans le r6seau capillaire. A strictement parler, l'an6mie est la diminution de la quantitd totale d'h6moglobine (Hb) fonctionnelle r lante. L'an6mie se d6finit h partir d'une valeur seuil de concentration de l 'Hb du sang p6riph6rique. Le clinicien doit consid6rer les limitations et impr6cisions d'un diagnostic bas6 sur une telle mesure, puisque s'il est indiqu6 de transfuser un patient an6mique (quantit6), la transfusion.est inappropri6e ?~ corriger un 6tat dilutionnel (concentration). La d6termination de la concentration d 'Hb est donc fortement influenc6e par les variations 6ventuelles du volume plasmatique (an6mie factice par h6modilution ou, au contraire, maintien initial de sa valeur lors de l'h6morragie g/gue) et sous-estime la concentration capillaire en h6moglobine. 1 Plus fondamentalement, cette mesure n'appr6cie en rien la tol6rance fonctionnelle de l'individu h son 6tat an6mique.

Question Compared to perioperative enoxaparin, does postoperative fondaparinux decrease the incidence of postoperative venous thromboembolism (VTE)?

Epsilon-aminocaproic acid and tranexamic acid, two synthetic antifibrinolytics, and aprotinin, an antifibrinolytic derived from bovine lung, are used to reduce excessive bleeding and transfusion of homologous blood products (HBP) after cardiac surgery. This review analyzes the studies on the utilization of antifibrinolytics in adult cardiac surgery according to the epidemiological concepts of efficacy, effectiveness and efficiency. A majority of published studies confirm the efficacy of antifibrinolytics administered prophylactically to reduce postoperative bleeding and transfusion of HBP. More studies are needed, however, to compare antifibrinolytics and determine if any one is superior to the others. Despite their demonstrated efficacy, antifibrinolytics are only one of the options available to diminish the use of HBP. Other blood-saving techniques, surgical expertise, temperature during cardiopulmonary bypass and respect of established transfusion guidelines may modify the effectiveness of antifibrinolytics to the point where antifibrinolytics may not be necessary. At this time, insufficient data have been published to perform a cost vs benefit analysis of the use of antifibrinolytics. This complex analysis takes into account not only direct costs (cost of the drug and of blood products), but also the ensuing effects of treatment such as: length of stay in the operating room, in the intensive care unit and in the hospital; need for surgical re-exploration; treatment of transfusion or drug-related complications, etc. In particular, the risk of thrombotic complications associated with antifibrinolytics is the subject of an ongoing, unresolved controversy. In conclusion, it is important for each institution to determine if their patient population (or a subset of this population) is likely to benefit from prophylactic treatment with antifibrinolytics, and to confirm that treatment is not associated with an increased incidence of untoward effects, before engaging in the routine use of any of these medications.

Despite the complications associated with transfusions,HBP remains an essential therapeutic modality, without which many major surgical procedures would be impossible. Clinicians must realize that transfusion of HBP is the most frequent transplantation of living tissue between humans. Even if known infectious complications could be eliminated, transfusion ofHBP will never be a totally safe procedure. New transfusion-related complications, the magnitude of which is unknown, such as graft-vs-host disease in immunocompetent patients, have emerged recently. Other, as yet unidentified, pathogens will undoubtedly be transmitted by HBP in the future.

In her book "Mindfulness," Ellen J. Langer reflects that the risk of relying on unquestioned routines prevents one from thinking and places one in the state of "mindlessness," a behaviour that sets the stage for accidents. ~ The constant questioning of every aspect of routine tasks will keep the mind busy and combat this state of mindlessness. One of the routines well entrenched in the practice of cardiac anaesthesia is the use of high doses of opioids and the prolonged postoperative mechanical ventilation of patients. Hall must be commended for questioning this routine practice of late extubation in patients undergoing coronary artery bypass grafting (CABG). 2 In this issue of the Journal, he makes the argument that postoperative management should not be dictated by the side effects of the drugs used for the management of anaesthesia. Rather, based on sound pharmacoldnetic reasoning, he describes the recently available alternative anaesthetic techniques that allow the choice of early extubation, if deemed beneficial for the patient. In 1969, Lowenstein reported that large doses of/v morphine avoided the problems in anaesthetic management secondary to the cardiac depressant properties of the anaesthetic agents employed at the time, thiopentone and halothane in particular, in patients requiring openheart surgery for acquired valvular disease, especially that of the aortic valve) Before 1966, several groups had advocated the routine use of postoperative mechanical ventilation in patients undergoing open cardiac procedures, so that these large doses of/v morphine allowed not only a safer intraoperative course, but also a smooth transition to postoperative ventilatory support. Nonetheless, as early as 1971, Lowenstein recognized that "the recent surge in coronary artery reconstructive operations warrants a reassessment of our practice, because most of these patients have not had chronically low output. "4 Thus, the question of early vs late extubation appears to have been a subject of controversy since the earlier days of cardiac surgery.