Vox Sanguinis International Forum on the use of prehospital blood products and pharmaceuticals in the treatment of patients with traumatic haemorrhage.

While specific practices and transported blood products vary around the world, most of the respondents in this International Forum transported at least one blood product for the transfusion to bleeding patients en route to the hospital. The most commonly carried product was RBCs, while the use of whole blood will likely increase given the recent reports of its successful use in the civilian setting, and because of the change in the AABB's Standards regulating its use. It will be interesting to see if plasma use in the prehospital setting becomes more widely used given today's enhanced appreciated of the coagulopathy of trauma and plasma's beneficial effect in reversing it, and if blood products are transported to the scene of injury by more vehicles, that is, not just predominantly in helicopters. It was not surprising that TXA is being widely administered as close to the time of injury as possible given its potential benefit in these patients. This International Forum highlights the importance of focusing attention on prehospital transfusion management with a need to further high­quality research in this area to guide optimal resuscitation strategies.

Mortality outcomes in patients transfused with fresher versus older red blood cells: a meta-analysis.

BACKGROUND: Among transfused patients, the effect of the duration of red blood cell storage on mortality remains unclear. This study aims to compare the mortality of patients who were transfused with fresher versus older red blood cells. METHODS: We performed an updated systematic search in the CENTRAL, MEDLINE, EMBASE and CINAHL databases, from January 2015 to October 2016. RCTs of hospitalized patients of any age comparing transfusion of fresher versus older red blood cells were eligible. We used a random-effects model to calculate pooled risk ratios (RRs) with corresponding 95% confidence interval (CI). RESULTS: We identified 14 randomized trials that enrolled 26 374 participants. All-cause mortality occurred in 1219 of 9531 (12·8%) patients who received a transfusion of fresher red blood cells and 1810 of 16 843 (10·7%) in those who received older red blood cells (RR: 1·04, 95% CI: 0·98-1·12, P = 0·90, I2 = 0%, high certainty for ruling out benefit of fresh blood, moderate certainty for ruling out harm of fresh blood). In six studies, in-hospital death occurred in 691 of 7479 (9·2%) patients receiving fresher red cells and 1291 of 14 757 (8·8%) receiving older red cells (RR: 1·06, 95% CI: 0·97-1·15, P = 0·81, I2 = 0%, high certainty for ruling out benefit of fresh blood, moderate certainty for ruling out harm of fresh blood). CONCLUSION: Transfusion of fresher red blood cells does not reduce overall or in-hospital mortality when compared with older red blood cells. Our results support the practice of transfusing patients with the oldest red blood cells available in the blood bank.

Elucidating the clinical characteristics of patients captured using different definitions of massive transfusion.

BACKGROUND AND OBJECTIVES: The type and clinical characteristics of patients identified with commonly used definitions of massive transfusion (MT) are largely unknown. The objective of this study was to define the clinical characteristics of patients meeting different definitions of MT for the purpose of patient recruitment in observational studies. MATERIALS AND METHODS: Data were extracted on all patients who received red blood cell (RBC) transfusions in 2010 at three tertiary Australian hospitals. MT patients were identified according to three definitions: ≥10 units RBC in 24 h (10/24 h), ≥6 units RBC in 6 h (6/6 h) and ≥5 units RBC in 4 h (5/4 h). Clinical coding data were used to assign bleeding context. Data on in-hospital mortality were also extracted. RESULTS: Five hundred and forty-two patients met at least one MT definition, with 236 (44%) included by all definitions. The most inclusive definition was 5/4 h (508 patients, 94%) followed by 6/6 h (455 patients, 84%) and 10/24 h (251 patients, 46%). Importantly, 40-55% of most types of critical bleeding events and 82% of all obstetric haemorrhage cases were excluded by the 10/24 h definition. Patients who met both the 5/4 h and 10/24 h definitions were transfused more RBCs (19 vs. 8 median total RBC units; P < 0·001), had longer ventilation time (120 vs. 55 h; P < 0·001), median ICU (149 vs. 99 h; P < 0·001) and hospital length of stay (23 vs. 18 h; P = 0·006) and had a higher in-hospital mortality rate (23·3% vs. 16·4%; P = 0·050). CONCLUSION: The 5/4 h MT definition was the most inclusive, but combination with the 10/24 h definition appeared to identify a clinically important patient cohort.

Experience with a massive transfusion protocol in the management of massive haemorrhage.

BACKGROUND AND OBJECTIVES: A massive transfusion response (MTR) was introduced in 2007 to provide blood and blood products in a timelier manner. Aim of this study was to determine whether implementation of the MTR was associated with a change in clinical practice or mortality. MATERIALS AND METHODS: All MTR activations from 2008 to 2011 were included in the study. Patients who had received a massive transfusion (MT ≥ 10 units RBC in 24 h) as part of the MTR (MT-MTR) were compared with a historical group of MT patients (MT-Pre-MTR) from 2004 to 2006. Blood product usage including fresh frozen plasma (FFP) : RBC and platelet : RBC ratios and mortality were compared between the two groups. RESULTS: Out of 169 MTR activations, 13 patients (8%) did not use any blood products, 73 (43%) used <10 units of RBC in a 24-h period and 83 received a MT. The median number of units of FFP and platelets transfused in the MT-MTR group were 10 [interquartile range (IQR) 7-17] vs 6 (5-10) [P < 0·001] and 3 (IQR 2-4) vs 2 (IQR 1-3) [P < 0·001] in the MT-Pre-MTR group of patients, respectively. The MT-MTR group received a higher 24-h FFP : RBC ratio (1 : 1·4 vs 1 : 2·4, P < 0·001). Overall mortality between the MT-MTR and MT-Pre-MTR groups (29% vs 23%, P = 0·43) and 90-day mortality was 25% vs 29% (P = 0·40), respectively. CONCLUSION: Although there has been a significant change in transfusion practice in MT patients using a MTR, no change in mortality could be documented using such a protocol.

Transfusion practices in massive haemorrhage in pre-intensive and intensive care.

BACKGROUND AND OBJECTIVES: Primary resuscitation for massive haemorrhage often occurs in emergency departments or operating theatres, with ongoing resuscitation in the intensive care unit (ICU). The aim of the study was to retrospectively review transfusion practice in the pre-ICU phase and ICU for patients with massive haemorrhage. MATERIALS AND METHODS: From 1998 to 2006, we developed an electronically linked database of blood and blood product usage and laboratory data with clinical outcome. All patients who received 10 or more units of red cells and required ICU admission were included. RESULTS: Of 238 patients who required massive transfusion, 40 died early (within 24 h of massive transfusion), out of which 16 died in pre-ICU and 24 died in ICU. Comparatively this group of patients presented in the pre-ICU phase and on ICU admission, respectively, with coagulopathy (median international normalized ratio 1.6 and 2.1) and acidosis (median base deficit -11.5 and -14 mmol/l). These patients had median ratios of fresh frozen plasma (FFP) to red blood cells of 1:3.3 and 1:1.3 in the pre-ICU and ICU phases, respectively. Severity of coagulopathy indicated by INR at ICU admission [P = 0.04; area under receiver operator curve (ROC) = 0.69] and RBC transfused (P = 0.01) in 24 h associated with mortality. CONCLUSIONS: Patients who died early were coagulopathic before and on ICU admission and did not correct their coagulopathy. This study also shows that coagulopathy is associated with an increased risk of mortality. Early and aggressive correction of coagulopathy for patients presenting with coagulopathy may be effective in improving mortality.

A 'dangerous' group O donor: severe hemolysis in all recipients of organs from a donor with multiple red cell alloantibodies.

Alloimmune hemolysis is a recognized but infrequent complication of solid organ transplantation, particularly where there is incompatibility within the ABO blood group system. We describe severe hemolysis due to passenger lymphocyte syndrome (PLS) in all three recipients of organs from a single donor with multiple red cell (RC) alloantibodies. The first patient, a liver transplant recipient, required augmentation of immunosuppression to treat immune hemolysis due to anti-B, -D, -C and -Cellano (k). This is the first description of PLS caused by alloantibody to the high incidence RC antigen, k. The two single lung transplant recipients developed hemolysis due to anti-D. Both required escalation of immunosuppression and early transfusion support. Three months posttransplant, all three patients have ongoing evidence of compensated hemolysis. This series highlights the potential for severe non-ABO-mediated immune hemolysis following solid organ transplantation. A positive donor RC antibody screen should prompt careful monitoring of organ recipients for hemolysis.

Discordance between ROTEM® clotting time and conventional tests during unfractionated heparin-based anticoagulation in intensive care patients on extracorporeal membrane oxygenation.

We hypothesised that ROTEM® (Basel, Switzerland) INTEM® (ROTEM, Basel, Switzerland) clotting time (CT) would have good agreement with activated partial thromboplastin time (aPTT) in determining whether a dose adjustment should be made to the unfractionated heparin (UFH) infusion in patients on extracorporeal membrane oxygenation. All patients treated with extracorporeal membrane oxygenation over a five-year period were included for data analysis. Retrospective analysis was performed of prospectively collected data points, wherein aPTT, activated CT and ROTEM was performed simultaneously to monitor UFH-based anticoagulation. Two hundred data points were available for analysis. Turnaround time was shortest for activated CT followed by ROTEM and aPTT. Despite achieving therapeutic aPTT targets, the majority (>50%) of INTEM CT results were within normal limits. The aPTT and INTEM CT results correlated weakly (r=0.31, 95% confidence interval [0.17, 0.43]) and there was no agreement between the directional changes of aPTT and INTEM CT results on successive days (x² =2.33, P=0.17). Due to relative insensitivity, INTEM CT-guided UFH titration was estimated to result in a 289% increase in incidence of up-titration, over aPTT-guided titration. The INTEM CT results (r=0.36, 95% confidence interval [0.23, 0.48]) correlated weakly with UFH infusion rates. The UFH infusion rate only explained 13% variability in INTEM CT values. While haemorrhagic complications were frequent, no major clotting complications were encountered. Our results demonstrated that aPTT and INTEM CT do not provide equivalent information to guide UFH infusion rate titration during extracorporeal membrane oxygenation. Our study suggests caution regarding the use of ROTEM for guiding UFH-based anticoagulation as it may lead to excessive UFH exposure.

Is the indirect antiglobulin crossmatch justified?

Pretransfusion testing has undergone a rationalization, resulting in a more efficient transfusion service but with no compromise to patient safety. Current debate centres on the necessity of performing an antiglobulin crossmatch if a suitable screening test for detecting red cell antibodies is negative. A retrospective study of all pretransfusion testing was undertaken to determine the specificities and possible clinical significance of antibodies detected by the crossmatch alone. The results indicate that omission of the crossmatch will not compromise patient safety. This will have benefits to both the patient and the laboratory. The patient will benefit because of less time needed to provide homologous donor blood. The laboratory will benefit from cost savings as a result of less antiglobulin reagent being used, less time taken for providing blood (and hence further cost savings) and less blood needing to be held in stock. The cost savings generated could be channelled into areas that will result in greater patient safety at a lower cost than crossmatching. Two of these areas are prevention of patient and specimen identification errors by the use of a unique transfusion number system and the full utilization of an autologous blood service.

Quinine-induced hemolytic uremic syndrome.

Although quinine use is very common, hemolytic uremic syndrome (HUS) following exposure to quinine is only a recently reported phenomenon, with the first description published in 1991. Previous reports have concentrated on the nature of the hematological process and in particular characterization of the quinine-induced antibodies involved. We present a case of HUS with a clear temporal and immunological relationship to quinine which demonstrates the pathognomonic renal features of HUS. An indirect antiglobulin test with the patient's serum agglutinated red blood cells only in the presence of quinine. Renal biopsy features included glomerular and arteriolar endothelial swelling, capillary loop thrombi, mesangiolysis, segmental sclerosis and segmental ischemia. Early empiric treatment with plasma exchange and corticosteroids was instituted and this resulted in recovery of renal function to normal.

Detection of the Tn antigen in leukaemia using monoclonal anti-Tn antibody and immunohistochemistry.

Exposure of the normally cryptic Tn antigen on haemopoietic cells leading to erythrocyte polyagglutination has been reported in a few cases of malignant or premalignant haemopoietic disorders and has been attributed to a selective deficiency of the enzyme 3-beta-D-galactosyl-transferase. A male patient presented with acute myelomonocytic leukaemia with no evidence of Tn expression but, 16 months later, in the terminal stage of the disease, the majority of the erythrocytes were found to be polyagglutinable. Tn expression was confirmed by the use of lectins and by agglutination with a Tn-specific monoclonal antibody, FBT3. Retrospective studies of stored blood and bone marrow smears were performed by immunocytochemistry using FBT3. Tn positive cells were first detected in the marrow 8 months prior to death. They increased progressively in number and, in the terminal illness, over 90% of erythroid precursors in the marrow and erythrocytes in peripheral blood and 40% of granulocyte precursors of the marrow and 10% of granulocytes in the blood were Tn positive. These observations suggest that Tn expression was present in a subclone of cells which became dominant during the course of the disease and that there may be a relationship between Tn expression and leukaemic progression.

Pure anti-Doa stimulated by pregnancy.

Pure anti-Doa stimulated by pregnancy was detected in 2 non-transfused females during routine antenatal screening. Anti-Doa occurs rarely and has generally been reported in combination with other antibodies. The first, and only report to date, of pure anti-Doa was also stimulated by pregnancy. We believe these instances to be only the second and third reported cases of pure anti-Doa.

A direct patient approach for pre-operative autologous blood donation and transfusion.

A patient-motivated pre-operative autologous blood transfusion service is described. The programme is organized and staffed by members of the Transfusion Service. In this programme patients who are enrolled for preoperative autologous blood collection are selected from elective surgical waiting lists without a formal referral from the surgeon. Since starting the scheme the average number of units donated per month has increased from 8 to 33 and complications have been minor. The system has proved to be practical and cost-effective, and it has a definite place as part of an overall approach to the prevention of transfusion-related complications.

Expression of a Tn-like epitope by carcinoma cells.

A monoclonal antibody, FBT3, was raised against Tn positive erythrocytes and, using immunohistochemistry, fresh and fixed tissues from patients with cancer were studied to detect any expression of a Tn-like epitope. Expression was found in neoplastic cells, usually both in cytoplasm and on cell membranes, from 104 of 147 cases of carcinoma and 1 of 13 cases of lymphoma, but rarely in adjacent, morphologically normal cells. Tn expression was seen in some normal glandular cells but, unlike cancer cells, it was distributed as fine granules in a supranuclear position. Detection of a Tn-like epitope is of theoretical interest and may be of direct diagnostic value.

Expression of the Tn antigen in myelodysplasia, lymphoma, and leukemia.

Expression of the normally cryptic blood group antigen Tn has occasionally been reported in hematologic disease, but the true frequency of this change is not known. A mouse monoclonal antibody (FBT3) and immunohistochemistry were used to examine expression of the Tn antigen. Expression was not detected in 35 normal bone marrow aspirates examined, but it was detected in 5 of 725 abnormal bone marrow aspirates, including 2 (3.6%) of 55 cases of de novo acute nonlymphocytic leukemia and 2 cases that terminated in acute nonlymphocytic leukemia. In two patients, one with acute myeloblastic leukemia and the other in blast transformation of chronic myeloid leukemia, the Tn antigen was expressed on 2 percent of blast cells. In one case of non-Hodgkin's lymphoma, 4 percent of normal myeloid cells expressed the antigen. In the other two cases, one of acute myelomonocytic leukemia and the other of myelodysplasia, only 2 to 8 percent of myeloid and erythroid cells initially were Tn positive. Subsequent serial immunohistochemical studies of bone marrow aspirates and peripheral blood in these two cases showed increasing numbers of Tn-positive erythroid and myeloid cells 8 to 12 months before polyagglutination was detected serologically. Tn-positive cells increased to > 90 percent in the terminal phase in both cases of both diseases. The results suggest that Tn expression in these two patients may have conferred a growth advantage to the cells and could be related to disease progression.

A LISS spin enzyme method for the detection of red cell antibodies and its use in routine antibody screen procedures.

A technique for performing the enzyme phase of the antibody screen on red cells suspended in low-ionic-strength-salt solution (LISS) is described. The reliability of this LISS spin-enzyme (LSE) technique was compared with the two-stage papain-tile method, in the detection of 62 previously identified enzyme reacting antibodies. All 62 antibodies examined were detected by the LSE method, and no false-positive reactions were found. Using LSE and papain-tile methods in parallel, further assessment was obtained by screening 2000 sequential blood samples under routine service conditions. Fifty-six blood samples contained alloantibodies, of which 43 reacted by both methods, eight by the LSE method only, and five by the papain-tile method only. It was concluded that the LSE method was comparable to the papain-tile method.

DNA polymorphism analysis in transfusion-associated graft-versus-host disease.

During cardiac surgery for transposition of the great arteries at age 7 weeks, a female infant received blood, fresh frozen plasma and platelet transfusions. Eleven days postoperatively, she developed bloody diarrhoea, fever, an erythematous macular rash, hepatomegaly, seizures and pancytopaenia. A clinical diagnosis of transfusion related graft-versus-host disease (GVHD) was supported by skin histopathology. DNA polymorphism studies confirmed that circulating lymphocytes in peripheral blood and infiltrating cells in the skin were foreign in origin and were derived from transfused blood cells. No underlying immunodeficiency was identified. Treatment with steroids cyclosporin and antithymocyte globulin was unsuccessful and death occurred 2 months after surgery. The features of fever, rash, diarrhoea, liver dysfunction and pancytopaenia which characterize GVHD may mimic drug reactions or viral infection. In addition to histological features on skin biopsy. DNA polymorphism studies on skin and blood samples provide a unique and sensitive method to confirm GVHD. Irradiation of blood products should be considered for acutely compromised infants requiring urgent cardiac surgery.

Effective use of blood in elective surgical procedures.

The preoperative requests for crossmatching of blood in elective surgical procedures were studied at the Flinders Medical Centre, South Australia. The study revealed that surgeons order crossmatched blood on the basis of habit. This led to considerable time-expiry of blood, and to unnecessary use of laboratory personnel's time and reagents. The statistical information collected during the study was used to educate the surgeons to change their blood-ordering practice. In procedures where excessive blood loss is unlikely to occur, as a stand-by, a "group-and-screen" procedure was substituted for crossmatching. A firm recommendation for maximum blood order in elective surgical procedures was also made. It is estimated that this approach would save approximately $80,000 per year per 350-bed general hospital in Australia.