Manuel Muñoz-Gómez

Impact of age of transfused blood on cerebral oxygenation in male patients with severe traumatic brain injury

Objective:Prolonged erythrocyte storage time might reduce the efficacy of transfusion. In this study, the effects of transfusion of erythrocytes with four different storage periods (<10 days, n = 18; 10–14 days, n = 15; 15–19 days, n = 17; and >19 days, n = 16 patients) on brain tissue oxygen tension (Ptio2) in stable male patients with severe traumatic brain injury were investigated during a 24-hr follow-up period. Design:Prospective, observational study. Setting:Neurotrauma critical care unit of a university hospital. Patients:Sixty-six male, nonbleeding, hemodynamically stable anemic patients (hemoglobin <95 g/L) with Glasgow Coma Scale score <9. Interventions:None. Measurements and Main Results:Ptio2, cerebral perfusion pressure, mean arterial pressure, intracranial pressure, peripheral oxygen saturation, CO2 pressure at the end of expiration, and intracerebral temperature were recorded in all patients at baseline, immediately after the completion of transfusion, and 1, 2, 3, 4, 5, 6, 12, and 24 hrs posttransfusion. All four groups were homogeneous with respect to multiple baseline variables, except for storage time of transfused erythrocytes (p < .0001). There was a significant short-lasting (3–4 hrs) increase in Ptio2 values after transfusion of erythrocytes stored for <10 days, 10–14 days, or 15–19 days, compared with those at baseline. In contrast, no significant changes in Ptio2 were observed after transfusion of erythrocytes stored >19 days. Conclusions:Transfusion of erythrocytes increased cerebral oxygenation in patients with severe traumatic brain injury, except in those transfused with erythrocytes stored >19 days.

Optimal hemoglobin concentration in patients with subarachnoid hemorrhage, acute ischemic stroke and traumatic brain injury

Purpose of reviewThe review outlines recent clinical and experimental studies regarding the effects of red blood-cell transfusion on clinical outcome in neurocritical patients, including patients with subarachnoid hemorrhage, acute ischemic stroke and traumatic brain injury. Optimal hemoglobin transfusion trigger and the role of other transfusion indicators for neurocritical patients are discussed. Recent findingsAcute anemia (hemoglobin levels near 7 g/dl) is well tolerated by healthy subjects, but extreme anemia might negatively affect clinical outcome of neurocritical patients. Conversely, high hemoglobin levels, attained by means other than red blood-cell transfusion, improve clinical outcome, whereas red blood-cell transfusion is associated with poorer clinical outcome (mortality, length of stay and disability) in patients presenting subarachnoid hemorrhage, acute ischemic stroke and traumatic brain injury. Studies defining the optimal hemoglobin concentration in neurocritical patients are lacking, but a restrictive transfusion policy seems to be safe and is often recommended. In the near future, signals coming from the brain, such as brain tissue oxygen tension and regional cerebral oxygen saturation, might potentially be developed into transfusion triggers. SummaryBoth severe anemia and red blood-cell transfusion may negatively influence clinical outcome in neurocritical patients. Acceptance of low hemoglobin concentrations may be justified by avoiding negative transfusion effects. No evidence-based transfusion trigger in neurocritical patients can be recommended.

Impact of national transfusion indicators on appropriate blood usage in critically ill patients

BACKGROUND: The objective was to investigate the impact of three national blood transfusion indicators (NBTIs) specifically designed for critical care regarding the appropriate blood transfusion indications.

Influence of Red Blood Cell Transfusion on CD4+ T-Helper Cells Immune Response in Patients Undergoing Cardiac Surgery

BACKGROUND Both surgical insult and red blood cell transfusion (RBCT) induce alterations in type-1/type-2, CD4T-helper cell balance. This study was aimed to determine the influence of RBCT on Th1 and Th2 function immune response in cardiac surgery patients. MATERIAL AND METHODS Three blood samples were prospectively drawn from 81 cardiac surgery patients with cardiopulmonary bypass (CPB): preoperatively (preOP), during CPB, before RBCT (intraOP), and on postoperative day 1 (postOP). Immune response was assessed by flow cytometry measurement of the proportion of CD4(+)T-helper cells producing tumor necrosis factor (TNF)-α [Th1 response] and interleukin (IL)-10 [Th2 response]. RESULTS Sixty-two patients were transfused (3.4 ± 2.3 units/patient), whereas 19 did not. Both groups were homogeneous, both at baseline and during surgery, regarding multiple perioperative clinical and laboratory variables, but postoperative blood loss and transfused RBC units were significantly higher in transfused versus nontransfused patients. In contrast, preoperative hemoglobin was significantly higher in nontransfused patients. CD4(+)T-helper cells significantly decreased in both groups of patients from preOP to intraOP 1 and from intraOP to postOP. In nontransfused patients, there were no significant changes in CD4(+)T-helper cells expressing TNFα or IL-10 among different sampling times. In contrast, RBCT resulted in a significant increment in Th2 response from intraOP to postOP (P=0.01), without affecting Th1 response. CONCLUSION RBCT, but not surgery or CPB, induces a shift of the Th1/Th2 balance toward Th2 dominance.

Red Blood Cell Transfusion Guided by Near Infrared Spectroscopy in Neurocritically Ill Patients with Moderate or Severe Anemia: A Randomized, Controlled Trial

In neurocritically ill patients (NCPs), the use of hemoglobin level as the sole indicator for red blood cell transfusion (RBCT) can result in under- or over-transfusion. This randomized controlled trial was conducted to ascertain whether a transcranial oxygen saturation (rSO2) threshold, as measured by near-infrared spectroscopy, reduces RBCT requirements in anemic NCPs (closed traumatic brain injury, subarachnoid, or intracerebral hemorrhage), compared with a hemoglobin threshold alone. Patients with hemoglobin 70-100 g/L received RBCTs to attain an rSO2 > 60% (rSO2 arm) or to maintain hemoglobin between 85 and 100 g/L (hemoglobin arm). A total of 102 NCPs (51 in each group) were included in the intention-to-treat analysis, and 97 were included in the per-protocol analysis (51 and 46, respectively). Compared with those from the hemoglobin arm, patients in rSO2 arm received fewer RBC units (1.0 ± 0.1 vs. 1.5 ± 1.4 units/patient; p < 0.05) and showed lower hemoglobin levels while in protocol. There were no differences between the study arms regarding the percentage of transfused patents (59% vs. 71%; relative risk 0.83 [95% CI 0.62-1.11]), stay on neurocritical care unit (21 vs. 20 days), unfavorable Glasgow Outcome Scale scores on hospital discharge (57% vs. 71%), in-hospital mortality (6% vs. 10%), or 1 year mortality (24% vs. 24%). Among NCPs with hemoglobin concentrations of 70-85 g/L, withholding transfusion until rSO2 is <60% may result in reduced RBCs requirements compared with routinely transfusing to attain a hemoglobin level >85 g/L. Further studies are required to confirm this finding and its possible impact on clinically significant outcomes.

Red blood cell transfusion guided by near infrared spectroscopy in neurocritically ill patients with moderate or severe anaemia

In neurocritically ill patients (NCPs), the use of hemoglobin level as the sole indicator for red blood cell transfusion (RBCT) can result in under- or over-transfusion. This randomized controlled trial was conducted to ascertain whether a transcranial oxygen saturation (rSO2) threshold, as measured by near-infrared spectroscopy, reduces RBCT requirements in anemic NCPs (closed traumatic brain injury, subarachnoid, or intracerebral hemorrhage), compared with a hemoglobin threshold alone. Patients with hemoglobin 70-100 g/L received RBCTs to attain an rSO2 > 60% (rSO2 arm) or to maintain hemoglobin between 85 and 100 g/L (hemoglobin arm). A total of 102 NCPs (51 in each group) were included in the intention-to-treat analysis, and 97 were included in the per-protocol analysis (51 and 46, respectively). Compared with those from the hemoglobin arm, patients in rSO2 arm received fewer RBC units (1.0 ± 0.1 vs. 1.5 ± 1.4 units/patient; p < 0.05) and showed lower hemoglobin levels while in protocol. There were no differences between the study arms regarding the percentage of transfused patents (59% vs. 71%; relative risk 0.83 [95% CI 0.62-1.11]), stay on neurocritical care unit (21 vs. 20 days), unfavorable Glasgow Outcome Scale scores on hospital discharge (57% vs. 71%), in-hospital mortality (6% vs. 10%), or 1 year mortality (24% vs. 24%). Among NCPs with hemoglobin concentrations of 70-85 g/L, withholding transfusion until rSO2 is <60% may result in reduced RBCs requirements compared with routinely transfusing to attain a hemoglobin level >85 g/L. Further studies are required to confirm this finding and its possible impact on clinically significant outcomes.