Discussion
The HVCM is at the forefront of using WB transfusion in patients with hemorrhagic shock in Latin America. Our experience shows that WB transfusion represents a feasible strategy for achieving hemostatic resuscitation in patients presenting in hemorrhagic shock, especially in LMICs. Through the implementation of a WB program, we were able to establish a program where patients would receive balanced resuscitation. Prior to the implementation of a WB program, patients were resuscitated with whatever components were available in the blood bank, which included a varying and often scarce number of pRBCs and FFP. The products dispensed from the blood bank and administered were not reliably documented, making a comparison before and after the implementation of this program impossible. Of the patients resuscitated with WB, we do not describe any symptoms consistent with transfusion reactions.
The use of WB is not a new concept. Prior to the adoption of component therapy in 1970s, resuscitation of patients in hemorrhagic shock with WB was commonplace.15 Component therapy was popularized for logistical reasons and was never proven to be as efficacious as WB in hemorrhagic shock.16 Recent literature from the military suggests that WB may have superior or equivalent outcomes when compared with component therapy. Two retrospective combat casualty analyses compared the use of fresh WB with component therapy.17 18 One study described a mortality benefit in the WB group at 24 hours and 30 days,18 whereas the other found no statistically significant difference in mortality, death due to exsanguination, multisystem organ failure, or sepsis.17 Nessen et al19 showed that, in the experience with forward surgical teams in Afghanistan, use of Fresh whole blood (FWB) in addition to RBCs and FFP was associated with improved in-hospital survival compared with RBCs and FFP alone. Within the civilian sector, retrospective analyses suggest superiority or equivalence of WB with regard to mortality and overall blood product use.20–23 The only randomized control trial in trauma patients, to our knowledge, compared modified WB (leukoreduced WB with additional platelet transfusion) with component therapy. After excluding patients with traumatic brain injury, a decrease in the use of component therapy was demonstrated in patients who received modified WB.24
A recent systematic review and meta-analysis comparing WB with component therapy found no difference in 24-hour or 30-day mortality. Importantly, this study highlighted the heterogeneity in the literature on WB transfusion in trauma. No study in this analysis was from the civilian setting in an LMIC.25 WB has important implications in LMICs, of which our work is only scratching the surface.
WB has both financial and logistical benefits compared with component therapy.26 WB has the advantage of being easy to store, transport, and administer to patients. Its use is ideal for resource-constrained environments and prehospital settings,16 27 especially those that do not have ready access to all blood components, delivering the product that would otherwise require three bags in one bag (figure 1).16 Moreover, when separated components are transfused, each unit contains an increased amount of anticoagulants and additives that contribute to a patient’s overall coagulopathy compared with one unit of WB.18 28 Spinella et al18 found that, in patients receiving massive transfusion, those receiving component therapy received a median of 825 mL of additional additives and anticoagulants compared with the group resuscitated with WB. Additionally, it has been asserted that the administration of WB may actually be safer for patients with respect to risk of transmission of bloodborne diseases, exposing them to one donor instead of multiple donors.29
Figure 1(Left) One unit of cold, fresh whole blood. (Right) One unit of packed red blood cells, fresh frozen plasma, and platelets.
Access to transfusion therapy and the “blood drought” create significant barriers to safe surgery in LMICs.30 The use of WB is potentially beneficial in countries where keeping up with a 1:1:1 transfusion ratio is not feasible. In resource-limited settings such as our institution in Southern Ecuador, a WB program has allowed us to streamline the prompt and expeditious administration of all blood components at once, thus ensuring higher concentrations of all primordial elements and thereby securing hemostatic strategy for patients in hemorrhagic shock. Prior to the implementation of this program, there was no way to guarantee the availability of balanced hemostatic resuscitation to patients in hemorrhagic shock.
It must be noted that Cuenca, Ecuador provides a favorable setting for implementing a WB program as 80% population is type O+ and 2% is type O− per the blood bank records.31 In our sample, most patients had type O+ blood, thereby making it easier to identify donors and more likely that a patient receiving a type O+ transfusion will be receiving a transfusion from a donor with the same blood type. The context for transfusion of patients in our region is distinct from the literature that typically recommends transfusion at a hemoglobin of 7 g/dL.32 Located at 2560 m above sea level, the average hemoglobin in this population is higher than at lower altitudes, estimated to range between 14.6 g/dL and 15.2 g/dL in women and 16.8 g/dL and 17.4 g/dL in men.33 As such, patients at our institution are often transfused at a higher threshold, typically 9 g/dL to 10 g/dL.
The primary concern with the transfusion of group O WB to non-group O recipients involves the possibility of minor ABO mismatch. This is typically mitigated by transfusion of only type-specific WB or through the transfusion of whole units with low titers of antibody (most commonly <256 by the saline dilution, immediate spin method), known as low-titer O whole blood (LTOWB).16 Numerous studies documented the safety of LTOWB, demonstrating that it does not increase risk of transfusion reaction.15 16 20 21 29 34 35 ,36 However, at the HVCM, anti-A and anti-B titers are not measured prior to administration of blood products. Data supporting the transfusion of untitered WB are scarce in the literature. In a safety analysis of the transfusion of stored WB, Yazer et al23 found that there was no statistically significant difference in the amount of incompatible plasma transfused in a unit of WB compared with the amount of incompatible plasma transfused in any unit of platelets (p=0.38). Sperry et al recently demonstrated a rate of adverse events possibly related to transfusions of 2.2% in a description of AB plasma and A plasma with low-titer B antibodies administered to patients in hemorrhagic shock in the prehospital setting.37 Severe intravascular hemolytic transfusion reactions caused by minor mismatch are a relatively rare phenomenon19 that may be difficult to detect in an otherwise critically ill patient and may not have been detected with the n of 101 in our series. While, again, we do not report any patients who developed symptomatology that was recognized as a hemolytic transfusion reaction, hemolysis laboratory tests post-transfusion were not routinely ordered. Several studies have documented that WB does not have evidence of increased hemolytic reactions with administration of up to four units.20 21 38
This study is limited in that it is a single-institution and retrospective study. There are many challenges that come with conducting research in a resource-limited setting, many of which affected this study. Although more patients were identified than described, many files were unable to be located in medical records. Documentation at HVCM continues to be written by hand, and many of the patient charts in medical records are missed pages or written illegibly. It should also be noted that documentation prior to the implementation of the TACS service (2012) was scarce. As such, the ability to compare this sample with patients resuscitated during an earlier time period is limited. The paucity of data in the paper charts also limited our ability to reliably determine the vital signs and laboratory values after transfusion.
