Reducing Inappropriate Overutilization of the Massive Transfusion Protocol

Introduction/Objective

Massive transfusion protocols (MTPs) make it possible to deliver blood products to exsanguinating patients in an efficient, sustained, and immediate manner. However, overutilization of MTPs continues to remain a significant problem for hospital blood banks. The study aims to address the characteristics of possibly inappropriate MTP activations during the first phase (cooler) at a level 1 trauma academic medical center.

Methods

This was a retrospective review of 328 phase 1 MTPs out of 696 total MTPs performed during a two-year period (Jan 1, 2017 and Dec 31, 2018) and divided into three categories: trauma, non-trauma surgery, and medicine services. We assumed that a possibly inappropriate MTP for trauma cases would show an Assessment of Blood Component (ABC) score of 1 or less and physicians used clinical discretion. For possibly inappropriate MTP non- trauma surgical and medicine cases, we devised a new system where we looked at only whether the blood pressure was equal to or less than 90 mm Hg and/or the pulse was greater than or equal to 120 beats per minute. If there was a score of 0 where there were neither vital sign criteria, then the MTP was considered possibly inappropriate.

Results

For trauma service, there were 43/168 (25.6%) cases that had an ABC score of 0, 49/168 (29.2%) cases that had an ABC score of 1, 53/168 (31.5%) cases that had an ABC score of 2, 21/168 (12.5%) cases that had an ABC score of 3, and only 2/168 (1.2%) case that had an ABC score of 4. Non-trauma surgery service had 31/51 (60.8%) cases with a new score of 0, 20/51 (39.2%) cases with a new score of 1, and 0/51 (0%) cases with a new score of 2. Medicine services had 57/109 (52.3%) patients with a new score of 0, 47/109 (43.1%) patients with a new score of 1, and 5/109 (4.6%) patients with a new score of 2. Non-trauma surgery service had the greatest possibly inappropriate MTP activations [31/51 cases (60.8%)], followed by trauma [92/168 (54.8%) cases] and medicine [57/109 (52.3%) cases].

Conclusion

Our study shows greater overutilization with MTPs using clinical judgment than with using the ABC criteria. Non-trauma surgery service had the greatest number of possibly inappropriate MTP activations at our hospital without having a significantly abnormal pulse or blood pressure. While ABC criteria is already liberal for activating an MTP, physician discretion appears to be more liberal in activating a possibly inappropriate MTP.

Limitations of the crossmatch for detection of incompatibility between A2B red blood cells and B patient sera

A recent evaluation of the immediate-spin crossmatch has revealed limitations when used for the detection of ABO incompatibilities in tests between group B patient sera and group A2B donor red blood cells. Presented with the option of deleting the anti-globulin crossmatch, the study reported here was conducted to determine whether the anti-globulin crossmatch would detect the ABO incompatibilities missed by the immediate spin. Results of 1,000 crossmatches between group B patient sera and group A2B red blood cells showed that the anti-globulin phase was capable of detecting a higher percentage of incompatibilities than the immediate-spin procedure, 79.4-86.8% versus 40-64.4%, respectively, depending on the enhancement used. Although anti-globulin testing did detect a substantially higher number of incompatibilities, are the increased cost of reagents and technologists' time used in performing the anti-globulin crossmatch justified for the detection of ABO incompatibilities? Due to limitations observed with the anti-globulin test in addition to budgetary and fiscal constraints, retention of the anti-globulin testing purely for ABO compatibility is not warranted.

Limitations of the immediate spin crossmatch when used for detecting ABO incompatibility

In the eleventh edition of the AABB's Standards for Blood Banks and Transfusion Services the requirement for an antiglobulin crossmatch was deleted if no clinically significant unexpected antibodies are detected in recipient serum testing and if there is no history of detection of such antibodies. Test methods that demonstrate ABO incompatibility remain a requirement; however, the means to accomplish this may prove controversial. The immediate spin crossmatch has been used for the purpose of detecting ABO incompatibility by many workers. Nonetheless, limitations of this technique became apparent in tests between A2B donor red cells and group B patient sera. The results of 204 of 531 immediate spin crossmatches, between these two blood groups, were found to be negative.

A guideline for anticipated blood usage during elective surgical procedures

A realistic guideline for transfusion therapy was prepared, with the cooperation of the departments of anesthesiology and surgery, in order to reduce excessive crossmatching. The guideline recommends an ABO-Rh type and an antibody screen, instead of the ""routine'' two-unit crossmatch, for elective surgical procedures where blood is seldom used. For those operations normally necessitating hemotherapy, the number of units suggested for the preoperative crossmatch was determined by examination of the average number of units transfused in the past for that particular procedure. The guideline provides the anesthesiologic and surgical staff with the knowledge of how much blood was usually used during a particular elective surgical procedure and therefore how much blood should be preoperatively crossmatched for that procedure. Implementation of this guideline allows the blood bank to distribute its limited blood resources more efficiently and also decreases patient and laboratory costs.

The type and antibody screen, revisited

The type and antibody screen is a safe, economical substitute for "routine" two-unit crossmatch in those elective surgical procedures rarely necessitating blood transfusion. This report confirms a previous finding that the type and antibody screen is 99.99% effective in preventing the transfusion of incompatible blood. The type and antibody screen is even safer than the stated 99.99%, when the immediate spin, saline and albumin procedures (the initial portion of the authors' complete crossmatch) are performed prior to releasing blood in an emergency situation. The immediate spin procedures not only verify the ABO compatibility but also detect any high-titer antibodies directed against low-incidence antigens that might not have been present on the screening reagent erythrocytes. The use of the type and antibody screen is applicable only in those medical facilities that have moderate reserves of blood readily available for transfusion.

Adult outpatient transfusion clinic in a hospital-based blood bank

Eighty-one patients have been followed in our ambulatory transfusion clinic for a total of 176 patient visits. They received phlebotomies, plasmapheresis, and transfusions of erythrocytes and platelets. Minor reactions (febrile reactions, transient hypotension, and urticaria) occurred in only six patients. The advantages of a transfusion service conducted by blood bank professional and technical staff are numerous. The nurse/patient ratio is low enough so that the patient can receive individualized attention including virtually constant vigilance. The laboratory staff and pathologist become familiar with the therapeutic management of patients who may potentially place great stress on the laboratory. The transfusion clinic also provides an opportunity for the pathologist to gain further experience and to train others as transfusion therapists, a role which he is often asked to assume when a transfusion reaction occurs. The gain for the outpatient clinic and emergency room is that they can function more efficiently when more rooms are available for patients who have a faster turnover time.

The type and screen: a safe alternative and supplement in selected surgical procedures

For the year 1975, we examined 12,848 blood specimens using the type and screen as well as the crossmatch and detected 283 antibodies in 247 patients. Our screening reagent red blood cells were able to detect 96.11 per cent of these antibodies. If the antigen frequencies corresponding to those antibodies not detectable by our screening reagent red blood cells are taken into consideration. i.e., the incompatibility frequencies, the type and screen can be shown to be 99.99 per cent effective in preventing the transfusion of incompatible blood. Therefore, we believe that the type and screen may be safey substituted for the routine two-unit crossmatch in those operative procedures usually not requiring transfusions. Adoption of this approach would reduce patient charges, provide for more efficient distribution of our limited blood supplies, and allow for more effective utilization of blood-bank technologist time.

Gamma globulin inhibition of fibrin clot formation

Myeloma gamma globulins have been reported to interfere with fibrinogen-fibrin conversion. A patient with multiple myeloma is described with a gamma globulin IgG1lambda concentration of 11 g per dl, prolonged thrombin time and poor clot retraction. Purified gamma globulin from the patient's serum and from normal serum caused prolongation of the thrombin time and reptilase clotting time assays in both normal plasma and in solutions of bovine fibrinogen. In addition, fibrin clots formed during the thrombin time assays were found to be ultrastructurally abnormal. This data suggests that the interaction of gamma globulin in the polymerization of fibrin may, in at least some cases, be due to nonspecific protein interaction.