Background: Coagulation tests are widely applied in clinical practice, among which PT and aPTT are the most commonly done. Among many preanalytical conditions –time, temperature and storage conditions are few of the factors affecting the results of samples. This study aims to compare PT and aPTT values in primary tubes and sample aliquots after 4 hours duration with the initial value. Materials & Methods : An observational study was done at Central Diagnostic Laboratory, Gandhi Hospital, Secunderabad, T.S. Samples were collected in citrated tubes, centrifuged, PT and aPTT were processed with plasma of primary tubes. Sufcient quantity of plasma was aliquoted immediately from primary tubes and kept at room temperature for 4 hours after which the plasma of primary tubes and aliquots were re-analyzed separately and values were compared. Results: Pearson correlation was performed to show the relation. PT and aPTT values obtained in the primary tube and aliquot were correlating with the initial value (PT-r =0.833,0.831 respectively) and (aPTT-r =0.97,0.87 respectively) and also with each other (PT-r =0.99) and (aPTT-r =0.90) respectively. There is no statistical signicant difference in PT of primary tube and aliquots when compared to initial PT (p>0.01). Incase of APTT there is statistically signicant difference in primary tube and aliquot when compared to initial value (p<0.01) where as there is no signicant difference of APTT values in aliquot and primary tube after 4 hours (p>0.01). Conclusion: The present study shows no difference of PT values in aliquots and primary tube when compared to initial value, whereas APTT values differ from initial values in samples stored for more than 4 hours in primary tube and aliquot.

Background: COVID-19 infection, discovered in Wuhan, China, engulfed vast population in most of the countries in a very short span, ranging from aymptomatic infection to acute respiratory distress syndrome, multiorgan failures and death. Individual studies on serum lactate dehydrogenase and albumin showed association with severity of disease. The purpose of present study is intended to predict the association of combined lactate dehydrogenase (LDH) to Albumin ratio with severity of COVID-19.Methods: A retrospective observational study was carried on already confirmed cases of covid 19 infection from July, 2021 to December, 2021 in Gandhi hospital, Secunderabad. History, clinical features and laboratory findings including LDH: Alb ratio was noted. Cases with known history of carcinomas, chronic kidney disease, chronic liver/lung disease, coronary artery disease, alcoholics were not included. Cases were divided into mild, moderate and severe based on National clinical management protocol for COVID-19. Data was analyzed using SPSS/Medcalc software.Results: LDH and LDH: Alb ratio was significantly raised with the severity of the disease. The AUC in ROC analysis of LDH: Alb ratio was 0.75 compared to 0.71 and 0.62 individually for LDH & Alb respectively; indicating ratio was superior to that of individual parameters.Conclusion: The present study shows significant correlation between LDH: Alb ratio with severity of COVID-19 infection. LDH: Alb ratio could be an easily available tool to predict COVID-19 severity.