Systematic review : effect of hemolysis on prothrombin time and activated partial thromboplastin time / Abbygene S. Arabe, Katrina T. Bueno, Roseann Marjorie S. Dela Cruz, Paolo Adrian S. Diolola, Kate Nicole C. Santos, Jiliana Bernice V. Sese, Jada Sofia D. Wallace; Kathlene Joy Labrador-Limcumpao.

Includes bibliographical nreferences.

Abstract: Hemolyzed specimens are normally rejected in Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT), unknowing its actual effects. Clinical Laboratory Standards Institute stated that hemolysis is one of the primary reasons for pre-examination errors and the most prevalent interference in clinical practice; therefore, advised to be rejected. This study was undertaken to review the effect of hemolysis on PT and APTT. Moreover, the study aimed to answer: (i) if there was a time difference between hemolyzed and non-hemolyzed specimens, (ii) the degree of hemolysis that produced a notable change, (iii) the type of hemolysis (in vivo or in vitro) that caused the change (iv) and other factors that might have influenced the results. The researchers obtained journals and articles by using databases from Google Scholar, MEDLINE, PubMed, ProQuest 5000 and UCentral. PICO (Population, Intervention/Exposure, Comparison, Outcome) and Cochrane Risk of Bias (Rob2) Quality Assessment Tool were utilized to assess the eligibility and to analyze the strength of evidence and bias for each data, respectively. Most of the studies showed that in order for the hemolysis to have a significant change in the results of PT and APTT, it should be categorized as moderate to marked hemolysis. However, specimens from laboratories commonly fall under the category of mild hemolysis with a hemoglobin concentration of 0.05 -0/1 g/dL, thus, has no clinical significance in the outcomes of PT and APTT. If the total allowable error that was recommended by CLIA will be utilized in assessing the results of PT and APTT, then hemolyzed specimens are still ideal and should not be rejected. In Vitro hemolysis was the one employed by all the studies that produced a notable change PT and APTT. Reagents used in hemolyzed samples might also affect the results of the coagulation studies. Moreover, some reviewed studies considered that the results of PT and APTT might have been influenced by those patients under oral anticoagulant therapy. Therefore, hemolyzed samples sent for PT and APTT can still be accepted and processed because almost all are categorized only as mild hemolysis - which does not have a clinical significance in the outcome of the results. Rejection of hemolyzed specimens is not necessary and recollection is not the convenient way in dealing with this interference. Hence, revaluation of CLSI guidelines on processing hemolyzed specimens is recommended as it will save time and will prevent possible consequences that might affect patients and health personnel.

Thesis - School of Medical Technology