Prolonged in vitro hemolysis of EDTA-anticoagulated blood after a delayed hemolytic transfusion reaction.

BACKGROUND: A novel case where in vitro hemolysis was observed in plasma, but not in serum samples, obtained after the onset of a severe delayed hemolytic transfusion reaction is presented. CASE REPORT: A 54-year-old woman received 2 units of blood during an orthopedic procedure. She had received transfusion 30 years earlier, and testing before transfusion revealed no alloantibodies. The patient returned 12 days after the transfusion with a Hb level of 54 g per L due to a severe delayed hemolytic reaction caused by anti-K. The plasma and serum samples were grossly hemolysed on Day 12. On Day 14, the serum samples showed no evidence of hemolysis; however, the EDTA sample remained grossly hemolysed. This discrepancy was not identified until Day 19. Due to concerns of ongoing apparent severe hemolysis, the patient was unnecessarily treated with IVIG and corticosteroids. The in vitro hemolysis was still present at 75 days, despite complete normalization of her Hb, bilirubin, and LDH levels. The phenomenon had resolved by 125 days. CONCLUSION: This in vitro artifact has not been previously reported and the mechanism remains unclear. Both plasma and serum samples should be observed for hemolysis when evaluating a patient with a severe delayed hemolytic transfusion reaction.

Reporting of near-miss events for transfusion medicine: improving transfusion safety.

BACKGROUND: Half of the reported serious adverse events from transfusion are a consequence of medical error. A no-fault medical-event reporting system for transfusion medicine (MERS-TM) was developed to capture and analyze both near-miss and actual transfusion-related errors. STUDY DESIGN AND METHODS: A prospective audit of transfusion-related errors was performed to determine the ability of MERS-TM to identify the frequency and patterns of errors. RESULTS: Events and near-miss events (total, 819) were recorded for a period of 19 months (median, 51/month). No serious adverse patient outcome occurred, despite these events, with the transfusion of 17,465 units of RBCs. Sixty-one events (7.4%) were potentially life-threatening or could have led to permanent injury (severity Level 1). Of most concern were 3 samples collected from the wrong patient, 13 mislabeled samples, and 22 requests for blood for the wrong patient. Near-miss events were five times more frequent than actual transfusion errors, and 68 percent of errors were detected before blood was issued. Sixty-one percent of events originated from patient areas, 35 percent from the blood bank, and 4 percent from the blood supplier or other hospitals. Repeat collection was required for 1 of every 94 samples, and 1 in 346 requests for blood components was incorrect. Education of nurses and alterations to blood bank forms were not by themselves effective in reducing severe errors. An artifactual 50-percent reduction in the number of errors reported was noted during a 6-month period when two chief members of the event-reporting team were on temporary leave. CONCLUSION: The MERS-TM allowed the recognition and analysis of errors, determination of patterns of errors, and monitoring for changes in frequency after corrective action was implemented. Although no permanent injury resulted from the 819 events, innovative mechanisms must be designed to prevent these errors, instead of relying on faulty informal checks to capture errors after they occur.

An evaluation of the process and costs associated with targeted lookbacks for HCV and general notification of transfusion recipients.

BACKGROUND: The Commission of Inquiry on the Blood System in Canada recommended that hospitals notify patients who received blood between 1978 and May 1990 of the risks of contracting HIV (up to the end of 1985 only) and HCV infection. The commission also recommended that patients should be informed of any transfusion received. STUDY DESIGN AND METHOD: General notifications for HIV and HCV for this period were begun in mid-1994. Notification after discharge of transfusions received after May 1990 was begun in 1997. Targeted HCV lookback was performed from 1995 to 1999. RESULTS: Of 21,016 transfusion recipients from January 1978 to May 1990 identified in the general look-back process and believed still alive, 13,549 (64%) were presumed contacted, by registered mail. The overall contact rate for the ongoing notifications (transfusions after May 1990) cannot be accurately determined, as registered mail was not used and a reply not requested. The total cost for these two processes was CAN$373,481, or $13 per patient believed contacted. Most (56%) of this cost was for the conversion to electronic form of paper transfusion records for the period 1978 through early 1984. In the targeted HCV lookback program 1995 through 1999, 94 percent of 256 recipients of specific components identified as likely to have transmitted HCV either were contacted or had died. Of 84 living recipients, 47 (56%) are HCV positive. The last documented potential seroconversion occurred after a transfusion in November 1991, during the period of first-generation EIA testing. If the targeted HCV lookback had been restricted to transfusions after 1987, as the FDA recommended, we would have failed to identify 39 living patients, of whom 21 are HCV positive. The cost per HCV-positive patient notified in the targeted HCV lookback was CAN $4,174. CONCLUSION: The cost of compliance with the com-mission's recommendations was CAN$569,636. Over 28,000 of 36,773 transfusion recipients were notified or presumed notified, and 272 targeted HCV lookbacks to 256 recipients were performed. Performance of this task required the existence of transfusion records back to 1978, conversion of paper records to electronic form, and adequate secretarial and financial support.

A gel technology system to determine postpartum RhIG dosage.

Failures of Rh immune globulin (RhIG) prophylaxis occur when the dose is too small. We report a test using a gel technology (GT) method to replace the Kleihauer-Betke (K-B) test to assess fetomaternal hemorrhage (FMH) and assist in determining the minimum necessary dose of RhIG. Cord blood (O, D+) was mixed with adult blood (O D-) to mimic an FMH of 10 mL, 20 mL, 28 mL, and 40 mL. Test samples were incubated with anti-D at known concentrations and centrifuged. The supernatant was titrated against D+ and D- red cells using GT and an interpretation of the required RhIG dose was made. Results were compared with the K-B test. Results were easily discernible and interpretations leading to determination of recommended RhIG dosage were reproducible. Correlation to standard K-B testing was confirmed. Elapsed time for result availability by GT testing was 60 minutes, with a direct technical time requirement of 30 minutes. The GT system is easier, objective, and quantitative, and compares well to the standard K-B test. A single procedure will allow assessment of the extent of FMH in the great majority of cases. This technique works well in determining the appropriate dose of anti-D required to treat D- patients with D+ newborns. There are potential cost savings in decreased use of RhIG, less direct technical time required, and more rapid availability of results.

Changes in red-cell transfusion practice in a tertiary care hospital during the 1990s--a 7-year study.

Use of red cells for transfusion in a tertiary care hospital has been studied over a 7-year period from 1990-1991 to 1996-1997. In this time, red-cell use has declined by 18% while new patients or admissions to programmes in oncology, trauma or cardiac bypass surgery have increased by 57%, 66% and 73%, respectively. This reduction in red-cell transfusion has been achieved by a combination of less patients (proportionately) receiving red cells and less red cells being transfused to individual recipients. When the trends are analysed for red-cell use in four elective surgical procedures there is a significant reduction in both the proportion of patients transfused and the mean number of units used per patient undergoing the procedure. Autologous presurgical blood deposit met about 45% of the blood requirement for those four procedures. A similar decreasing trend in units per patient and proportion of patients transfused red cells was seen for 'first-time' coronary artery bypass surgery. The question arises as to how far this trend may go before adverse effects of undertransfusion become apparent.

Assessment of an instrument for automated reagent and specimen dispensing in blood banking.

We have evaluated a semi-automated computer controlled dispensing device in conjunction with microtube technology for the performance of routine blood grouping and antibody screening procedures. A total of 787 specimens have been tested, 78 with unexpected antibodies previously identified by manual microtube methods. All were tested in duplicate in different order; there was complete agreement in blood group (ABO, RhD) determinations and the unexpected antibodies were found in the appropriate microtube location in all duplicate sets of results. We conclude that the device accurately and reproducibly dispenses cells, sera and reagents. The savings of technologists' time over traditional manual tube methods exceed 75%, excluding the time to perform elements common to both methods. The combination of automation and microtube technology offers the opportunity for substantial savings in technologist time with accuracy in reagent and specimen dispensing.

Transfusion practice in support of surgery during introduction of a hospital-based autologous presurgical blood donor program.

OBJECTIVES: To assess blood use in support of elective surgery during the introduction of a hospital-based presurgical autologous blood donor program and to identify changes in transfusion practice. DESIGN: Case series over a 3-year period. SETTING: A tertiary-care, university-affiliated hospital. PATIENTS: All patients (887) who underwent, electively, one of four major surgical procedures between Apr. 1, 1990, and Mar. 31, 1993, during introduction of the hospital's autologous blood transfusion program. The criteria for donation were wide. INTERVENTIONS: Hip and knee arthroplasty, radical hysterectomy and radical prostatectomy. MAIN OUTCOME MEASURES: Increase or decrease in the use of autologous or allogeneic blood for transfusion for the four surgical procedures over the study period. RESULTS: For hip arthroplasty, the use of blood decreased significantly overall. The use of blood in support of radical hysterectomy and prostatectomy decreased but not significantly. In knee arthroplasty, blood use increased for reasons still under investigation. The contribution of autologous blood for the four procedures increased over the 3 years of the study from 17% to 55%, and constituted 3.8% of red cell and whole blood transfusions. Avoidance of allogeneic transfusion in the 3rd year of the study was 64% for patients who underwent hip arthroplasty, 71% for those who underwent radical prostatectomy and 77% for those who underwent knee arthroplasty and radical hysterectomy. CONCLUSIONS: Hospital-based autologous blood collection with wide eligibility criteria can contribute significantly to the availability of blood for elective surgery and can prevent allogeneic blood exposure in about 75% of patients who undergo, electively, one of four common procedures. Compared with other centres, there is room for further reduction in allogeneic blood exposure.

Positive antiglobulin test in association with sulindac: involvement of the Rh factor.

We investigated the development of a positive direct antiglobulin test associated with the use of the nonsteroid anti-inflammatory drug sulindac. The drug was shown to be the cause of the positive direct antiglobulin test using red cells treated in vitro with solutions of native sulindac and its two major metabolites. Serum from the patient contained sulindac-dependent red cell antibodies which could not be demonstrated when red cells having the Rh phenotype D-- were employed in the test procedure. An eluate prepared from the patients' red cells reacted against untreated red cells having common Rh phenotypes, but not against target red cells with the Rh phenotypes D-- or Rh null. The eluate showed stronger reactivity against the cells having common Rh phenotypes when they were treated with solutions of a metabolite of sulindac, but failed to react against treated red cells having the Rh phenotype D-- or Rh null. The results of our investigations point to an interaction between sulindac and/or its metabolites and Rh structures on the red cell membrane as the initial step in the production of drug dependent and autoantibodies leading to the positive direct antiglobulin test.

Frequency of delayed hemolytic transfusion reactions following antibody screening and immediate-spin crossmatching.

In view of the continuing controversy regarding the use of immediate-spin crossmatch procedures in preparing blood for transfusion to patients in whom unexpected clinically significant antibodies have not been found by antibody screening by the indirect antiglobulin test (IAT), a review of 8 years' experience with such a policy was conducted. In that period, 54,725 units of packed red cells or whole blood were transfused to 10,146 patients. Four clinically overt delayed hemolytic transfusion reactions and 18 clinically silent delayed serologic transfusion reactions were found. In 3 of the 22 patients, the offending antibody(ies) were detectable in the pretransfusion serum by an enzyme IAT, but none was detectable by routine saline IAT against either a three-cell screening panel or the transfused cells. Thus, the incorporation of saline indirect antiglobulin crossmatch would not have prevented the delayed reactions. It can be concluded that the use of a saline indirect antiglobulin crossmatch offers no significant advantage over the current policy of using only immediate-spin crossmatch for those patients whose pretransfusion serum gives negative results in a three-cell screen using a saline IAT.

Audit of the use of packed red blood cells in association with seven common surgical procedures.

The risks and costs associated with the transfusion of blood and its components have led to increasing demands for evidence of the appropriate use of blood components. We have examined the use of packed red blood cells (PRBC) in association with seven common, surgical procedures performed in 1987 and 1988 to establish patterns of use. The information has formed the basis for surgical blood order schedules and autologous donation targets for these procedures. It has also been used to determine appropriate audit 'triggers' and the results of an audit using these 'triggers' are reported.

Transfusion of ABO-incompatible platelets causing severe haemolytic reaction.

Not infrequently clinical demand dictates that patients receive transfusions of ABO-incompatible platelets when there is a short supply of group-specific platelets. This carries a risk of causing a haemolytic reaction, as illustrated in the clinical case we report. In discussing this potential complication, we suggest a strategy for avoiding it.

Seven years experience with group O unmatched packed red blood cells in a regional trauma unit.

The introduction of a blood component system has made Group O unmatched packed red blood cells (G O UPRBCs) available for emergency resuscitation from hypovolemic shock. A seven-year retrospective review is presented, describing the use of 537 units of G O UPRBCs for the resuscitation of 133 trauma patients. This represented 9.1% of all patients admitted to the Regional Trauma Unit who received blood for resuscitation. Ten of 116 patients on whom further blood bank testing was performed developed positive direct antiglobulin tests (seven of these were demonstrated to be negative 48 hours after transfusion); seven of the ten patients had received more than eight units of G O UPRBCs. No clinical complications were encountered. G O UPRBCs are safe and efficient for emergency resuscitation. Non-group O patients receiving eight or more units of G O UPRBCs should not receive unmatched type-specific blood.