J.A. García Erce

Foro de debate: seguridad de las alternativas a la transfusión alogénica en el paciente quirúrgico y/o crítico

In recent years, several safety alerts have questioned or restricted the use of some pharmacological alternatives to allogeneic blood transfusion in established indications. In contrast, there seems to be a promotion of other alternatives, based on blood products and/or antifibrinolytic drugs, which lack a solid scientific basis. The Multidisciplinary Autotransfusion Study Group and the Anemia Working Group España convened a multidisciplinary panel of 23 experts belonging to different healthcare areas in a forum for debate to: 1) analyze the different safety alerts referred to certain transfusion alternatives; 2) study the background leading to such alternatives, the evidence supporting them, and their consequences for everyday clinical practice, and 3) issue a weighted statement on the safety of each questioned transfusion alternative, according to its clinical use. The members of the forum maintained telematics contact for the exchange of information and the distribution of tasks, and a joint meeting was held where the conclusions on each of the items examined were presented and discussed. A first version of the document was drafted, and subjected to 4 rounds of review and updating until consensus was reached (unanimously in most cases). We present the final version of the document, approved by all panel members, and hope it will be useful for our colleagues.

Hemólisis, hipercalemia y transfusión de concentrados de hematíes viejos en pacientes críticos

We have read with great interest Chacón-Alves et al.’s work on post-transfusion hemolysis in anemic critically ill patients who are stable at 72 h. We wish to congratulate the authors for their new approach. We share with the authors their worry on the effectiveness and safety of allogeneic blood transfusion (ABT) that should be administered not for the management of anemia, but ‘‘to transfuse the minimal necessary amount to reverse the symptoms and signs of hypoxia or reach safe concentrations of hemoglobin (Hb) based on the clinical characteristics of each patient at a given time’’. The ABT is a transient measure, and we should not just treat one analytical number, because we could end up having the same need if we don’t treat the cause. We propose a change toward the paradigm of ‘‘optimal or adequate use’’. Above all, when it comes to the methodology used and results from their work, we would like to know whether they considered several risk factors associated with the ABT of packed red blood cell (PRBC) concentrates. Has the age of the PRBC concentrate been registered? The age has been related with a lower viability of erythrocytes. In some countries and several Spanish autonomous communities, the expiration date of PRBC has been dropped to 35 days, and attempts have been made to make it go further down to 28--31 days only. Also, the age of the PRBC concentrate has been associated with a higher risk of hyperkalemia, the appearance of post-transfusion cardiovascular events, and respiratory distress. Have the levels of post-transfusion potassium been estimated? Was the higher or lower compat-

Distrés respiratorio agudo secundario a la transfusión sanguínea

We have read the recent histopathological review entitled: ‘‘acute respiratory distress’’ (ARD) with interest. However, we found that the publication made no mention of ARD associated to blood transfusion. A differential diagnosis must be established among transfusion-related acute respiratory distress (TRD), transfusion-related acute lung injury (TRALI), and cardiogenic lung edema or transfusion-associated circulatory overload (TACO). Transfusion-related acute lung injury is defined as ‘‘acute dyspnea with hypoxia and bilateral pulmonary infiltrates during or in the 6 hours after transfusion, unrelated to overload or other likely causes’’. The presence of TRALI is to be suspected in ‘‘patients without evidence of acute lung injury prior to transfusion’’ who develop ARD. Table 1 describes the diagnostic criteria. Transfusion-related acute lung injury is a clinical syndrome, and the presence of antibodies is not strictly necessary to establish the diagnosis. Transfusion-associated circulatory overload lacks a consensus-based definition. According to the current definition of the International Society of Blood Transfusion (ongoing revision), any four of the following conditions must be met within the first 6 h after transfusion: acute respiratory failure, tachycardia, increased arterial pressure, acute lung edema or worsening of edema, or evidence of a positive fluid balance. The diagnosis is established on an exclusion basis and requires a high degree of suspicion: ‘‘TACO is to be suspected in the presence of respiratory difficulties that improve with treatment for circulatory overload (diuretics, morphine and nitrates)’’, and ‘‘it is important to report these cases’’. The experts that review these cases find it difficult to classify them--often because the essential data are not available and the transfused patients are frequently elderly (over 70% of the units being administered to patients over 70 years of age) or in critical condition (over 40% in emergency care or in Intensive Care Units), and with