RESUMO
Selected quality issues pertinent to the determination of accurate results in the haemostasis laboratory are discussed. Specifically, the implementation of a successful external quality-assessment scheme is described, including its impact on result accuracy as well as the programme's unique challenges and opportunities. Errors in the preanalytical phase of laboratory testing represent the greatest source for reporting incorrect test results. Some of the most common preanalytical errors are described including those that necessitate sample rejection. Analytical means to identify potential sources of error and analytical means to overcome particular interferences are described. Representing the most important clinical complication in the treatment of patients with haemophilia, quality issues related to determination of the presence of inhibitory antibodies against factor VIII (FVIII) are reviewed. Heat treatment of patient plasma prior to testing, particularly in patients receiving replacement FVIII concentrate or during induction of immune tolerance to achieve more accurate results is recommended, while screening activated partial thromboplastin time-based mixing tests to rule out inhibitor presence is discouraged. The initiatives presented in this review can be implemented in robust and resource restricted settings to improve the quality of laboratory testing in patients with bleeding disorders.
