Didier Barnoud

FVIIa corrects the coagulopathy of fulminant hepatic failure but may be associated with thrombosis: A report of four cases

PurposeDuring liver transplantation, excessive blood losses are correlated with increased morbidity and mortality. Blood losses are particularly high in the case of urgent liver transplantation for fulminant hepatic failure (FHF). Recombinant activated factor VII (rFVIIa) has shown promise in treating the coagulopathy of liver disease. We review our experience with the use of rFVIIa in treating the coagulopathy of FHF during urgent liver transplantation.Clinical featuresWe report four patients with FHF who met King’s College criteria for liver transplantation and in whom rFVIIa was used after conventional means for treating the associated coagulopathy had failed. In all patients, the coagulation defect was corrected by rFVIIa. However, thrombotic complications occurred in two patients (myocardial ischemia and portal vein thrombosis) and the implication of rFVIIa cannot be excluded.ConclusionWe conclude that rFVIIa is effective in the correction of the coagulopathy associated with FHF However, thrombotic events are of concern and therefore, further studies are warranted to define the safety of rFVIIa in that setting.RésuméObjectifPendant la transplantation hépatique, d’importantes pertes sanguines entraînent une hausse de la morbidité et de la mortalité. Ces pertes sont particulièrement élevées lors d’une transplantation d’urgence pour Insuffisance hépatique fulminante (IHF). Le facteur VII recombiné activé (rFVIIa) s’est montré prometteur contre la coagulopathie de la lésion hépatique. Nous passons en revue notre expérience de l’usage du rFVIIa pour traiter la coagulopathie de l’lHF pendant la transplantation hépatique d’urgence.Éléments cliniquesNous présentons quatre patients atteints d’IHF qui répondaient aux critères du King’s College pour la transplantation hépatique et chez qui le rFVIIa a été utilisé après l’échec du traitement traditionnel de la coagulopathie associée. Le rFVIIa a corrigé le défaut de coagulation chez tous les patients. Cependant, deux patients ont subi des complications thrombotiques (ischémie myocardique et thrombose de la veine porte) pour lesquelles l’implication du rFVIIa ne peut être exclue.ConclusionLe rFVIIa est efficace pour corriger la coagulopathie associée à l’IHF Néanmoins, les événements thrombotiques sont préoccupants et appellent à la réalisation d’autres études pour définir l’innocuité du rFVIIa dans ce contexte.

Double-lung transplantation using donor lungs with a right tracheal bronchus

A 58-year-old man underwent sequential bilateral lung transplantation. On the donor heart-lung block, it was discovered that the right apical segment was supplied by a tracheal bronchus. After the separate implantation of both lungs, a right apical segmentectomy was performed and the postoperative course was uneventful. The management of this problem is discussed.

Adaptation de la nutrition artificielle en cas d'insuffisance rénale aiguë et de recours aux techniques d'épuration extracorporelle en réanimation

Artificial nutrition management can be affected by the occurrence of acute renal failure (ARF). Indeed this organ dysfunction, which is frequent in ICU, has two main consequences: 1) metabolic disorders related either to the causal disease or to the metabolic consequences of renal failure, 2) the method used (hemofiltration and/or hemodialysis) may interfere with metabolic and nutritional consequences of this organ failure. Among various metabolic consequences, renal replacement therapy permits these ARF-patients to be provided with adequate nutritional intakes. Although replacement therapy is responsible for losses of nutrients such as glucose, aminoacids, peptides, vitamins and trace elements (lipophilic substances, which are not water-soluble, are not dialyzed), this is probably only of a minor importance. Indeed, there is almost no actual nutritional deficiency directly related to the renal replacement therapy except for hypokaliemia and hypophosphatemia, which are much more frequent during hemodialysis. The occurrence of ARF does not affect the nutritional needs as compared to similar patients without ARF. Hence recommended energy intake is 120–130 % of resting energy expenditure, or should match the actual energy expenditure whenever assessed, protein intakes should be 1.25–1.5 g/kg body weight, and the glucose/lipid ratio is close to 60 %/40 %. The needs for micronutrients and vitamins are not really modified by ARF and intakes should follow the recommended values. In the case of probable or documented deficiency (vitamins B1 and B9, selenium, zinc) intakes must be adapted. Finally the prefered route for nutritional supply must be enteral (gastric or jejunal) as generally recommended in the ICU, parenteral nutrition being reserved for real necessity.

EBV-B cells as antigen presenting cells in characterization of the self/donor context of allorecognition by T lymphocytes

Alloreactivity is caused by T cell recognition of foreign histocompatibility antigens according to two models: (i) indirect recognition, in which processed allogeneic antigens are presented by self-major histocompatibility complexes like any other foreign antigen, and (ii) direct recognition, where the foreign MHC itself is recognized breaking the T cell recognition rule of self-restriction. This paper uses these two cases of alloantigen presentation as illustrative examples to investigate (i) the capacity of Epstein-Barr virus-transformed B cells (EBV-B cells) to process alloantigens, and (ii) in vitro assays with EBV-B cell lysate as a source of alloantigen, in order to characterize alloreactive T cell populations. A microculture system was established using donor EBV-B cell lysate as a source of the allogeneic antigen and donor or recipient EBV-B cells as antigen presenting cells to investigate whether alloantigen is recognized by effector T cells from the recipient. T lymphocytes produced after expansion in the presence of interleukin-2 from four samples of liver biopsies (three patients) and four samples of bronchoalveolar lavages (four patients) were used as effector cells. Upon human leucocyte antigen class II typing, these expressed the patient phenotype. When the T lymphocytes were from liver grafts, the recognition involved donor antigens presented by donor EBV-B cells (direct recognition). On the other hand, when the T lymphocytes were cultured from lung grafts, they mainly recognized antigens of donor EBV-B cell lysates in a self-restricted context (indirect recognition). These data suggest that EBV-B cells can provide allogeneic determinants recognized by T cells in donor or self-contexts, i.e. through either direct or indirect recognition.