Changes in transfusion practice over time in the PICU.

OBJECTIVES: Recent randomized clinical trials have shown the efficacy of a restrictive transfusion strategy in critically ill children. The impact of these trials on pediatric transfusion practice is unknown. Additionally, long-term trends in pediatric transfusion practice in the ICU have not been described. We assessed transfusion practice over time, including the effect of clinical trial publication. DESIGN: Single-center, retrospective observational study. SETTING: A 10-bed PICU in an urban academic medical center. PATIENTS: Critically ill, nonbleeding children between the ages of 3 days and 14 years old, admitted to the University of Maryland Medical Center PICU between January 1, 1998, and December 31, 2009, excluding those with congenital heart disease, hemolytic anemia, and hemoglobinopathies. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the time period studied, 5,327 patients met inclusion criteria. Of these, 335 received at least one RBC transfusion while in the PICU. The overall proportion transfused declined from 10.5% in 1998 to 6.8% in 2009 (p = 0.007). Adjusted for acuity, the likelihood of transfusion decreased by calendar year of admission. In transfused patients, the pretransfusion hemoglobin level declined, from 10.5 g/dL to 9.3 g/dL, though these changes failed to meet statistical significance (p = 0.09). Neonatal age, respiratory failure, shock, multiple organ dysfunction syndrome, and acidosis were associated with an increased likelihood of transfusion in both univariate and multivariable models. CONCLUSIONS: The overall proportion of patients transfused between 1998 and 2009 decreased significantly. The magnitude of the decrease varied over time, and no additional change in transfusion practice occurred after the publication of a major pediatric clinical trial in 2007. Greater illness acuity and younger patient age were associated with an increased likelihood of transfusion.

Transfusion medicine in trauma patients: an update.

In 2008, we reviewed the practical interface between transfusion medicine and the surgery and critical care of severely injured patients. Reviewed topics ranged from epidemiology of trauma to patterns of resuscitation to the problems of transfusion reactions. In the interim, trauma specialists have adopted damage control resuscitation and become much more knowledgeable and thoughtful about the use of blood products. This new understanding and the resulting changes in clinical practice have raised new concerns. In this update, we focus on which patients need damage control resuscitation, current views on the optimal form of damage control resuscitation with blood products, the roles of newer blood products, and appropriate transfusion triggers in the postinjury setting. We will also review the role of new technology in patient assessment, therapy and monitoring.

Transfusion practice in the intensive care unit: a 10-year analysis.

BACKGROUND: Clinical guidelines recommend a restrictive transfusion strategy in nonhemorrhaging critically ill patients. STUDY DESIGN AND METHODS: We conducted a retrospective observational study of 3533 single-admission patients, without evidence of acute coronary syndromes, hemorrhage, or hemoglobinopathy admitted to the medical intensive care unit (MICU) of a large, academic medical center. RESULTS: MICU admission hemoglobin (Hb) level did not change significantly over the study period. The proportion of transfused patients decreased from 31.0% in 1997 to 1998 to 18.0% in 2006 to 2007 (p<0.001). Among patients receiving transfusion, the mean pretransfusion Hb level decreased over time from 7.9±1.3 to 7.3±1.3g/dL (p<0.001). These changes in practice were not accounted for by differences in patient characteristics. The mean nadir Hb level in nontransfused patients decreased from 11.2±2.2g/dL in 1997 to 1999 to 10.4±2.3g/dL in 2006 to 2007 (p<0.001). The mean number of units per patient transfused decreased during this time from 4.3±4.7 to 3.0±3.8 units (p<0.001). The proportion of transfused patients who were transfused at a Hb level of less than 7.0g/dL increased by an estimated absolute increment of 3.2% (95% CI, 2.1%-4.3%) per interval (p<0.001), and the proportion of single-unit transfusions during the first transfusion episode increased by 1.4% per interval (95% CI, 0.2 to 2.6%; p=0.03) from 40.2% in 1997 to 1998 to 53.1% in 2006 to 2007. CONCLUSIONS: Between 1997 and 2007, important and sustained changes have occurred in our MICU physician transfusion practices, with overall reductions in the proportion of patients transfused, mean pretransfusion Hb level, and nadir Hb level in patients who were not transfused.

Washing platelets in neutral, calcium-free, Ringer's acetate.

BACKGROUND: Washed platelets (PLTs) are occasionally requested for patients with histories of allergic or anaphylactic reactions. Washing methods and conditions result in the loss of PLT number and function. Short postwash storage times occasionally conflict with other patient activities and result in the wastage of washed products. Better washing procedures are a start to longer postwash hold times. STUDY DESIGN AND METHODS: Twenty-six units of just-outdated 6- or 7-day-old apheresis PLT concentrates were sampled; washed in neutral, calcium-free, Ringer's acetate (NRA); allowed to recover for 0.5 hour; and resampled. PLTs were counted, subjected to transmission electron microscopy, diluted with either equal-volume NRA (prewash) or autologous plasma (postwash), and subjected to thromboelastography. Pre- and postwash products were compared. RESULTS: PLT recovery was 71%. Plasma removal was 96%. Electron microscopy PLT morphology was unchanged by washing. Thromboelastography showed a mild decrease in final clot strength after washing that was not related to PLT concentration. CONCLUSIONS: PLT washing in NRA allows good recovery of PLT numbers and good preservation of function in vitro as assessed by thromboelastography. If performed in a closed-system cell washer, extension of the current 4-hour storage time for washed PLTs should be possible.

Transfusion medicine in trauma patients.

Injured patients stress the transfusion service with frequent demands for uncrossmatched red cells and plasma, occasional requirements for large amounts of blood products and the need for new and better blood products. Transfusion services stress trauma centers with demands for strict accountability for individual blood component units and adherence to indications in a clinical field where research has been difficult, and guidance opinion-based. New data suggest that the most severely injured patients arrive at the trauma center already coagulopathic and that these patients benefit from prompt, specific, corrective treatment. This research is clarifying trauma system requirements for new blood products and blood-product usage patterns, but the inability to obtain informed consent from severely injured patients remains an obstacle to further research.

Safety of uncrossmatched type-O red cells for resuscitation from hemorrhagic shock.

BACKGROUND: Uncrossmatched type-O packed red blood cells (UORBC) are recommended for immediate transfusion in hemorrhaging trauma patients. The potential for alloimmunization with this technique is controversial, and has been reported to be as high as 80%. We examined a 1-year experience with UORBC transfusion to determine the incidence of allergic reaction and alloimmunization. METHODS: Blood Bank and Trauma Registry databases for the year 2000 were linked to determine the incidence of UORBC use and the characteristics of patients, including the incidence of transfusion reactions and seroconversion of Rh-patients. Ten units of type-O, Rh+ blood (and two units of O-blood for women of childbearing age) were available for immediate transfusion, 30 to 45 minutes sooner than type-specific or crossmatched red blood cells. UORBC were administered to any patient with signs of severe hemorrhagic shock, at the discretion of the attending physician. RESULTS: In all, 480 trauma patients (out of 5,623 admitted) received transfusions of RBC, totaling 5,203 units. Five hundred eighty-one units of UORBC were given to 161 patients. Average Injury Severity Score in the UORBC cohort was 33.8. Patients receiving UORBC received an average of 16.9 total units of red blood cells, 14 units of plasma, and 10 units of platelets. Seventy-three patients died (45%). There were no acute hemolytic transfusion reactions observed in the patients who received UORBC. Four Rh-women received UORBC, all O-. Ten Rh-men received O+ blood, and only one developed antibodies to the Rh antigen. CONCLUSION: The need for UORBC is associated with significant injury and the need for subsequent massive transfusion. In this largest reported trauma series, the use of UORBC enabled rapid administration of red cells to hemorrhaging patients, without discernible risk for transfusion-related complications. The rate of seroconversion of Rh-patients is lower than reported in the literature, perhaps due to immune suppression associated with hemorrhagic shock.

Blood transfusion rates in the care of acute trauma.

BACKGROUND: Ten to 15 percent of all RBCs are used in the care of injury. Understanding patterns of RBC use is important. Routine resource allocation, planning for mass casualty situations, designing research, and optimizing triage all can be usefully informed. STUDY DESIGN AND METHODS: Blood Bank and Trauma Registry records were linked to produce a transfused blood product list for each patient directly admitted from the scene of injury to a large Level 1 trauma center in calendar year 2000. Categorical associations between demographic data, Injury Severity Score, transfused products, and outcome were sought. Special attention was paid to the groups receiving uncross-matched RBCs and more than 10 units of RBCs. RESULTS: Eight percent (479/5645) of acute trauma patients received RBCs, using 5219 units and sustaining an overall mortality of 27 percent. Sixty-two percent of RBCs were given in the first 24 hours of care. Three percent of patients (147 injured) received more than 10 units and received 71 percent of all RBCs given. Mortality in this cohort was 39 percent. Ninety percent of the patients who received more than 10 units of RBCs received plasma, and 71 percent received PLTs. CONCLUSIONS: A small number of patients receives most of the blood products used in the treatment of injury. Transfusion of more than 10 units of RBCs identifies a subgroup where most patients received plasma and PLTs to treat actual or anticipated dilutional coagulopathy. There is no clear threshold beyond which blood use is futile.