Moffat, Karen A.

Abstract Abstract 1415 Poster Board I-438 Introduction: Critical laboratory values (CVs) are those that indicate the patient is in danger of death unless corrective action is initiated immediately. CVs are an important feature of laboratory practice parameters, standards of regulatory agencies (including the Joint Commission's National Patient Safety Goals), and national and institutional quality improvement studies. However, there has been no research into CVs in coagulation laboratories. Our objectives were to determine: 1) The current policies on CVs in specialized coagulation laboratories 2) Current patterns of practice for reporting CVs for coagulation parameters; and 3) If there is any consensus, based on practice, on CVs for coagulation tests. Methods: A web-based survey on CVs was distributed to members of the North American Specialized Coagulation Laboratory Association in February 2009. Results: 38 laboratories participated. 97% had CVs for coagulation tests in place. 85% of laboratories used local opinion or consensus to set their CV policies, likely reflecting a lack of published data. 9% of laboratories were unsure where their CVs came from. CV reporting practices were fairly uniform. 97% of surveyed laboratories authorized technologists to report CVs, and only a minority (<40%) involved senior technologists or laboratory physicians in reporting. CV policies at almost all sites (97%) authorized the patient's nurse or MD, or the ordering MD to receive CV results. Medical students, clerical staff, or uninvolved staff nurses were rarely authorized to receive CVs (3%, 13%, and 37%, respectively). Policies in all participating laboratories required documentation of CV communication. Telephone was the primary method of communication, with 39% of sites used electronic broadcast or forced print as an adjunct. Inconsistency was noted in strategies to handle repeat CVs on the same patient, ranging from reporting all CVs, to reporting worsening CVs, to not reporting CVs on certain patient populations (e.g. critical FVIII:C levels in known hemophiliacs). After-hours communication of CVs on outpatients and referred clients was identified as challenging. All sites first attempted to telephone the patient's on-call MD, and if unsuccessful, sent a report by facsimile, contacted the Laboratory Chief of Service, or delayed reporting until the next day. When laboratories were asked about their CV values, over 80% had CVs for the INR (mean > 5, range > 2 - 6), aPTT (mean > 100 sec, range > 45 - 150 sec) and fibrinogen level (mean < 90 mg/dL, range < 50 - 100 mg/dL). Fewer laboratories (< 25%) had CVs for less commonly performed coagulation tests, including anti-Xa levels, factor and inhibitor assays, and thrombophilia testing. These CVs were more heterogeneous. Conclusion: This survey identified several potential areas for improvement in the way specialized coagulation laboratories handle CVs. Consensus data would assist laboratories in standardizing their policies, and establishing benchmarks for CV reporting and policy review. It would also ensure that a laboratory's CVs are in line with those of its peers, and are clinically relevant. The workload associated with CVs for coagulation assays is unknown, and it is possible that some of the current reporting strategies lead to inefficiencies and delays (e.g. reporting CVs for tests that are not truly life threatening; lack of established policies for after-hours handling of CVs when an on-call physician cannot be reached). Our study identifies an important need for further evaluation and standardization of CVs for coagulation tests. Disclosures: No relevant conflicts of interest to declare.

AbstractIntroductionPlatelet function disorders (PFD) are an important group of bleeding disorders that require validated and practical laboratory strategies for diagnosis.MethodsThis review summarizes the authors’ experiences, current literature, and an international survey to evaluate the practices of diagnostic laboratories that offer tests for PFD.ResultsBlood counts, blood film review, and aggregation tests are the most commonly performed investigations for PFD and help determine whether there is thrombocytopenia and/or defective platelet function due to a variety of causes. The performance characteristics of tests for PFD, and the level of evidence that these tests detect bleeding problems, are important issues to determine where tests are useful for diagnostic or correlative purposes, or research only uses. Platelet aggregation assays, and quantitative analysis of platelet dense granule numbers, are tests with good performance characteristics that detect abnormalities associated with increased bleeding in a significant proportion of individuals referred for PFD investigations. Lumiaggregometry estimates of platelet adenosine triphosphate release show greater variability which limits the diagnostic usefulness. Diagnostic laboratories report that fiscal and other constraints, including a lack of high‐quality evidence, limit their ability to offer an expanded test menu for PFD.ConclusionPFD are clinically important bleeding disorders that remain challenging for diagnostic laboratories to investigate. While some PFD tests are well validated for diagnostic purposes, gaps in scientific evidence and resource limitations influence diagnostic laboratory decisions on which PFD tests to offer.

Abstract Platelet function testing is important for the diagnostic evaluation of common and rare bleeding disorders. Our study goals were to promote best practices and reduce unnecessary testing variances by developing North American guidelines on platelet function testing. Guidelines were developed by consensus for expert recommendations (minimum level for approval, 70%) that included recommendations on the evaluation and interpretation of light transmission platelet aggregometry (LTA). To assess consensus, medical opinions on recommendations were gathered from diagnostic laboratories that perform LTA, in collaboration with the Quality Management Program–Laboratory Services (QMP-LS) in Ontario, Canada (10 laboratories), and the North American Specialized Coagulation Laboratory Association (NASCOLA; 47 laboratories, 5 overlapping the QMP-LS group). Adequate consensus was achieved for all and 89% of recommendations for the QMP-LS and NASCOLA groups, respectively. The recommendations adopted provide North American laboratories with additional guidance on platelet function testing, including how to interpret LTA abnormalities.

Abstract Performance on specialized diagnostic tests for platelet disorders, including dense-granule deficiency, is rarely evaluated by external quality assessment (EQA). Members of the North American Specialized Coagulation Laboratory Association that evaluate platelet dense-granule deficiency commonly use whole-mount electron microscopy (EM) methods. This observation led us to develop a pilot EQA survey with standardized EM images and clinical samples on grids from a healthy control subject and a subject with dense-granule deficiency. The survey participants were 8 centers, including 2 with no experience in platelet whole mount EM. All participants, including inexperienced sites, correctly interpreted findings for the normal and dense-granule-deficient platelets. Among experienced sites, agreement was excellent (&gt;82%) on platelet structures to count or not count as dense granules. Participants indicated that future EQA challenges should include clinical samples on grids and standardized images. This is the first report that platelet EM can be assessed by EQA.