Hemolysis and short samples on coagulation tests. Then the samples were kept at room temperature for 3 h to simulate specimen transportation time. After the test; the samples were subjected to in vitro hemolysis.
Sachin Kolte, Department of Pathology, R.
The lysis of red cells results in the presence of red-cell stroma, and the release of ADP and other pro-coagulant factors. This article has been cited by other articles in PMC.
For optical-detection instruments, the interference can be longer clotting times, due to the color change from hemoglobin, or shorter times due to the presence of pro-coagulant factors.
In coagulation assays rejection of hemolyzed samples is commonly recommended by testing device manufacturers and accrediting organizations. There was trend of increase in the readings of PT and aPTT in normal population and there was trend of decrease in the reading in patient population.
A total of 45 blood samples were collected from two groups of healthy donors and patient population. Therefore this study was planned with the aim to study the changes in the readings of PT and aPTT in hemolyzed and non-hemolyzed blood samples.
Samples were collected by a clean venipuncture from a vein different and distant from the vein having intravenous cannula. There was no difference observed in hemolyzed and non-hemolyzed samples.
The approval from ethics committee was taken for drawing blood samples from volunteers. CLSI recommends the use of 3. The extent of hemolysis and the presence of these factors activate platelets and, subsequently, the coagulation cascade.
Excess citrate in the plasma will chelate reagent calcium, making it less available for clot formation in the reaction.
After collection the tube was gently mixed by inverting it times. The difference between paired samples from group one was not statistically significant, but it was significant in samples from second group.
The level of interference from hemolysis is patient dependent. No differences were found in healthy subjects. The additional cost is incurred per re-collected specimen, adding to the overall cost of laboratory operation. These samples belonged to patients who were admitted and majority of them were from intensive care unit.
The clinical and Laboratory Standards Institute, in its guidelines for prothrombin time PT and activated partial thromboplastin time aPTT testing, states that samples with visible hemolysis should not be used because of possible clotting factor activation and interference with end point measurement interference.
This was primarily due to the collection of blood through venous-access devices or peripheral catheters. These samples were subjected to hemolysis and testing was carried out in same manner as those with the first group.
The true impact of hemolysis on coagulation studies is little studied in clinical practice. Bleeding disorders, Coagulation, Diagnostics, Hematology Introduction Receiving hemolytic specimens for laboratory tests is a common phenomenon in many of the clinical laboratories and it is one of the important factors that affect pre-analytical errors in many of these laboratories.
The blood samples were collected in citrated vacuum containers in the proportion of 1: Under-filling of collection tubes can occur by premature removal of the tube from the needle, by insufficient transfer from a syringe, or by "natural" factors such as high altitude.
Mechanical-detection methods can exhibit shorter clotting times, similar to optical methods, from pro-coagulant factors.
The impact of an altered ratio depends upon the concentration of citrate in the tube and upon the patient i. The incidence of hemolysis has increased with the decentralization of phlebotomy practices to non-laboratory personnel.The effects of varying degrees of hemolysis and its effect on PT and APTT results were not able to be studied.
Limitations Although subsequently collected samples were received within 24 hours from the receipt of the initial sample, the results obtained from the non-hemolysed specimens may not be truly representative of the patient’s initial state. Forty pairs of samples (spontaneous in vitro haemolysis versus nonhaemolysed) were available and tested with all the reagents for PT, APTT and fibrinogen.
Haemolysis distribution across samples was as follows: (+): 15 samples, (++): 19 samples, (+++): 6 samples. Table 1 and Figures depict the results obtained for the different assays. Topic: Impact of haemolysis in accuracy of PT/APTT (Important of fast and accurate PT/APTT results in managing patients) CHAPTER 2: LITERATURE REVIEW.
PT and APTT. Theprothrombin time(PT) and its derived measures ofprothrombin ratio(PR) andinternational normalized ratio(INR) are measures of the extrinsic pathway of.
Prothrombin time (PT), activated partial thromboplastin time (aPTT), and selected factor assay test results for consecutive pairs of hemolyzed and subsequently recollected (mean, 72 minutes later. For all three APTT reagents, the impact of haemolysis was sufﬁcient to impact patient management decisions, and in some samples, the effects of lipaemia and icterus Accurate results are therefore key for appropriate diagnosis.
Limiting errors with all the reagents for PT, APTT and ﬁbrinogen. Haemolysis distribution across samples. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) as indicators of coagulation rate were determined using a coagulatometer.
All of the plant extracts tested had a significant effect on coagulation time, prolonging the aPTT. Cassia petersiana had the greatest prolonging effect on PT compared to the control, PBS.Download