Practical handling of hemolytic, icteric and lipemic samples for coagulation testing in European laboratories. A collaborative survey from the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM).

Abstract

Objectives: Coagulation test results may be affected by hemolysis, icterus and/or lipemia (HIL). Detailed guidelines for HIL-management are missing, both for manual and automatic HIL-checks. The aim of this survey was to provide an overview of the practical procedures for the detection and handling of HIL-samples used by laboratories in Europe in the context of coagulation testing.

Methods: A SurveyMonkey questionnaire was sent from the Haemostasis Working Group in the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM) to European external quality assurance organizers, who in turn forwarded the link to their participating laboratories. Questions were asked regarding detection and handling of HIL-samples, comment- and reject-levels, and the guidance used by the laboratories.

Results: A written procedure for HIL-management was available in 55-67 % of laboratories, and each sample was checked for HIL in 73-83 % (lowest percentage for icterus, highest for hemolysis). Manual visual inspection as the only method to detect HIL was used by up to 38 % of laboratories, with most relying on personal experience for HIL-level classification. All other laboratories used some type of automated HIL-detection, alone or in combination with visual check. The terms used for classification and the HIL comment- and reject-levels varied widely, even among laboratories using the same manufacturer. Most laboratories state that they use the manufacturer's guidance.

Conclusions: There is wide heterogeneity in HIL-detection, handling and reporting among European laboratories, which calls for an urgent collaboration among laboratories and manufacturers to harmonize the HIL-management in coagulation testing.