ABSTRACT
Abstract Understanding the physiological concepts of oxygen delivery is essential to discern the mechanisms that influence its increase, reduction or maintenance in the body. This text explores the different mechanisms that help maintain oxygen delivery even in the face of reduced hemoglobin levels. Adequate oxygen delivery ensures tissue and metabolic balance, which is crucial to avoid harmful consequences such as metabolic acidosis and cellular dysoxia. The complex interaction between variables such as cardiac output, hemoglobin and heart rate (HR) plays a fundamental role in maintaining oxygen delivery, allowing the body to temporarily adjust to situations of anemia or high metabolic demand. It is important to emphasize that blood transfusions should not be based on fixed values, but rather on individual metabolic needs. Strategies to reduce myocardial consumption and monitor macro and micro hemodynamics help in making rational decisions. Individualizing treatment and considering factors such as blood viscosity in relation to the benefits of transfusion are increasingly relevant to optimize therapy and minimize risks, especially in complex clinical scenarios, such as neurocritical patients and trauma victims.
ABSTRACT
Abstract Postoperative anemia is a complex clinical issue that requires attention due to its ramifications on the patient's recovery and prognosis. Originating from multiple determinants, such as intraoperative blood loss, hemolysis, nutritional deficiencies, systemic inflammation and impact on the bone marrow, postoperative anemia has varied and often challenging presentations. Patients undergoing major surgical procedures, in particular, are susceptible to developing anemia due to the considerable associated blood loss. Accurate diagnosis plays a crucial role in the approach, requiring meticulous hematological analysis, including hemoglobin, hematocrit and reticulocyte count, as well as an in-depth investigation of the underlying causes. An additional challenge arises in the form of the excessive practice of phlebotomy during hospitalization for clinical monitoring. Although it is essential to assess the progression of anemia, frequent removal of blood may contribute to iatrogenic anemia, further delaying recovery and possibly increasing susceptibility to infection.
Subject(s)
Anemia , Blood Transfusion , ErythropoietinABSTRACT
ABSTRACT Background: Zika, a disease caused by Zika virus infections, has recently emerged and caused outbreaks in many parts of the world. The clinical manifestations of Zika are usually mild, mostly presenting as an exanthematic febrile disease, but on some occasions, it might be associated with microcephaly after intrauterine infection, and Guillain-Barré Syndrome. Zika virus is primarily transmitted by mosquito bites, but other means of transmission have been described, and potential risk for blood transmission has been reported in French Polynesia and Brazil. Methods: To investigate the risk of Zika virus infection after a blood transfusion in an area of Brazil where a possible transmission by a platelet concentrate has been described. Using a mini-pool format, 1857 blood donations were evaluated by real-time reverse transcriptase polymerase chain reaction designed to detect Zika virus RNA. Results: After testing samples individually from positive mini-pools, the prevalence of Zika virus RNA was only 0.16%, a result probably associated to the low circulation of this virus in the study area. In addition, it was evident that the implementation of post-surveillance programs is important to detect Zika virus infections in blood donors, as the post-donation surveillance program detected two blood donors with the disease in this study. Conclusion: This study shows that the risk for Zika virus transmission by blood transfusion is real, even in regions with a low circulation of the disease, but the combination of the detection of Zika virus RNA by polymerase chain reaction and post-donation surveillance might reduce the risk of transmission by blood transfusions.