HELLP syndrome: laboratory parameters and clinical course in four patients treated with plasma exchange.

We report our apheresis department's experience with four patients with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome. The average age of the patients was 23.25 years (range 19-27). Three were in their second pregnancy while one was a primigravida. All had symptoms of pre-eclampsia prior to delivery. All experienced the syndrome postpartum. Plasma exchange was instituted an average of 3.25 days postpartum (range 1.08-7.33 days). All underwent plasmapheresis with fresh frozen plasma replacement. The average number of plasma exchange treatments was four (range 1-8). The first laboratory parameter to reach its peak/nadir was the aspartate aminotransferase (AST), followed by the lactate dehydrogenase (LDH) enzyme level, followed by the hemoglobin (HGB) level, and, finally, the platelet count (PLT). The AST was the first parameter to peak and the first to normalize. In the three cases in which more than one plasmapheresis procedure was performed, plasmapheresis was required for an average of 98 hours (range 39-206 hours) after a normal AST level was obtained in order to achieve a self-sustaining platelet count of > or = 100 x 10(9)/L. No additional exchanges were required to maintain the PLT once a PLT of over 100 x 10(9)/L was attained. The laboratory values normalized in the following order: AST, HGB, PLT, and LDH. Three patients were discharged anemic. One was discharged with a normal LDH level. By our experience, awaiting normal LDH levels as an indicator for cessation of plasma exchange therapy would mean subjecting the patients to many unnecessary procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

National survey of neonatal transfusion practices: II. Blood component therapy.

Neonatal transfusion practices during 1989 of 452 institutions involved in transfusing infants were surveyed by questionnaire. Most respondents (77%) transfused fresh frozen plasma appropriately (ie, primarily to treat coagulation disorders). However, 11% stated that their most frequent use of fresh frozen plasma was solely to treat hypovolemia, a practice generally not recommended. Seventy-eight percent of respondents transfused platelets to treat bleeding infants with blood platelet counts of less than 50 x 10(9)/L; 84% gave platelets to sick, premature neonates with counts of less than 50 x 10(9)/L whether or not bleeding was evident. Only 35% of respondents transfused granulocytes for neonatal sepsis; most institutions used buffy coats isolated from units of blood--a product readily available, but of questionable efficacy when compared with leukapheresis granulocytes. Ninety-three percent of respondents provided blood components with low risk of transmitting cytomegalovirus: components from seronegative donors were used by 84%, leukocyte-reduced products by 6%, and a combination by 10%. Thirteen percent of respondents gave gamma-irradiated blood components to all and 46% gave them to some neonates to prevent graft vs host disease. Forty-one percent did not routinely irradiate. Ten percent of respondents used leukocyte reduction instead of gamma irradiation to prevent graft vs host disease, a practice currently not advocated. Thus, national transfusion practices for neonates are variable, controversial, and, occasionally, other than those usually recommended. Additional research and educational efforts are needed to ensure optimal transfusion therapy.

National survey of neonatal transfusion practices: I. Red blood cell therapy.

Neonatal blood component transfusion practices during 1989 were surveyed via a questionnaire developed by the Pediatric Hemotherapy Committee of the American Association of Blood Banks. Of 1790 questionnaires mailed, 452 were selected to form the database for this analysis because they were from institutions in which neonates were transfused. Nearly all institutions contained intensive care units directed by neonatologists and were involved in the management of high-risk infants. Results from institutions serving as the primary pediatric teaching hospital of a medical school were compared with those with no medical school affiliation. Thirty-six percent of primary pediatric teaching hospitals and 52% of hospitals with no medical school affiliation performed pretransfusion testing in excess of that required, resulting in additional blood loss in neonates. Sixty-six percent of primary pediatric teaching hospitals used fresh frozen plasma to adjust the hematocrit of red blood cell concentrates prior to transfusion (a practice increasing donor exposure), compared with only 29% of hospitals with no medical school affiliation. The usual indication for small-volume red blood cell transfusions in severely ill neonates was to maintain a desired hematocrit level, whereas for stable infants, red blood cell transfusions were given to treat symptomatic anemia, rather than to maintain a predetermined hematocrit. As found in 1985, neonatal transfusion practices in 1989 were variable. However, improvements have occurred since 1985 to suggest that further research and educational efforts may serve to promote even better neonatal transfusion therapy.

National acceptability of American Association of Blood Banks Pediatric Hemotherapy Committee guidelines for auditing pediatric transfusion practices.

In 1989, guidelines for the auditing of pediatric transfusion practices were developed by the Pediatric Hemotherapy Committee of the American Association of Blood Banks (AABB) and made available to AABB members. A survey of members who requested the guidelines was conducted to determine how consistent the guidelines were with local transfusion practices and how useful they were for the conduct of audits. The majority of respondents indicated that the recommended audit criteria agreed with local practices and that most of them could be applied to their transfusion practice audits with little or no modification. An exception was that criteria for the transfusion of platelets to premature infants were considered by some to be too liberal. However, after review of the comments and the published information available, the committee elected not to revise the guidelines pertaining to platelet transfusions for premature infants. Bearing in mind that audit criteria are intended to identify circumstances in which transfusions are acceptable as reasonable therapy without need for further justification, rather than to serve as indications for transfusions, the AABB Pediatric Hemotherapy Committee guidelines for auditing pediatric transfusion practices are fairly representative of national practice.

Procedural errors in antibody identification.

In experimental studies of students and line technologists performing antibody identification procedures, both groups made errors. These errors included, at times, either failing to identify an antibody or misidentifying the specficity(ies)A. prospective study was undertaken to identify errors made in a laboratory setting. Errors were classified as 1) failing to follow protocol (procedural error) or 2) arriving at the wrong answer (misidentification error). Over a 1-year period, 1,057 workups were reviewed. There were 41 (3.88%) procedural errors and no misidentification errors. In 25 workups (61% of errors), the selection of cells m rule out underlying alloantibody(ies) was in error. The remaining 16 involved various "slips" (minor mistakes or memory lapses) and clerical errors. Based on an analysis of the probable causes of these errors, potential solutions include 1) developing computer aids to detect "rule-out" errors or missing tests results; 2) providing timely, careful review of workups before transfusion; and 3) designing better panel layout and cell selection.

Determining the significance of anti-Kl in hemolytic disease of the newborn (HDN).

Anti-K1 is capable of causing severe hemolytic disease of the newborn (HDN), but few cases are seen due to the low frequency of the antigen. A total of 1,215 pregnancies from 1962 to 1989 were reviewed. There were 404 non-anti-D clinically significant antibodies, of which 103 (25%) were anti-K1. Anti-K1 was detected in nine of the women at delivery, of whom two had antigen-positive infants who were clinically unaffected. Antigen typing was done on 64 of the 85 fathers. Forty-seven were K - 1 and 17 were K1,2; 21 were unavailable. Antibody titers were done on the mothers in the latter two groups. Women with titers <32 were followed by titration studies; all delivered clinically unaffected infants, four of whom were K:1. Women with titers >32 had amniocentesis performed for optical density values (AOD450) or, after November 1987, were offered an alternative test, cordocentesis, to type the fetus and to do hemoglobins if the fetus was antigen-positive. Two women had severely affected infants requiring multiple intrauterine transfusions starting at 20-23 weeks. Six others delivered antigen-positive infants who did not require transfusions, although all had positive direct antiglobulin tests (DAB). We conclude that titration studies are reliable tools to evaluate anti-K1 sensitization when the titer is <32. Cordocentesis can detect antigen-negative fetuses, which then reduces the need for titrations and amniocentesis.