No abstract available.
Humans ; Prothrombin Time* ; Prothrombin*

Introduction: To date, there are no reference intervals for prothrombin time (PT) and activated partial thromboplastin time (APTT) based on “normal” Filipino adults. The common practice in most laboratories is to adopt manufacturer provided values or foreign literature even if the importance of establishing or at least verifying laboratory reference intervals has been stressed by Clinical Laboratory Standards Institute (CLSI). Objectives: Here we aim to describe our experience in using a simple non-parametric method to generate reference intervals for PT and APTT, from healthy Filipino volunteer blood donors. Methodology: We used a de novo, a priori non-parametric estimation method following the CLSI guidelines on establishing reference intervals. Results: The non-parametric lower reference limit for PT is 12.55 seconds, with 90% confidence interval of 12.3 to 12.75 seconds. While the non-parametric upper reference limit for PT is 16.15 seconds, with 90% confidence interval of 15.55 to 16.55 seconds. The non-parametric lower reference limit for activated partial thromboplastin time is 26.12 seconds, with 90% confidence interval of 22.95 to 27.1 seconds, and the non-parametric upper reference limit for activated partial thromboplastin time is 37.44 seconds, with 90% confidence interval of 36.75 to 38.65 seconds. The PT and APTT reference intervals were different from foreign sources and manufacturer provided values in terms of interval width and values of the reference limits by 2 to 4 seconds. Conclusion and Recommendations Estimation of coagulation reference intervals from volunteer health blood donors is doable, simple, and practical. Collaborative multi-center efforts may be done to expand the pool of reference individuals that are included and increase the representativeness of the reference intervals generated. This simple method can also be used to generate reference intervals for other clinical laboratory assays and may also be extended to at least verify reference intervals in special populations like pregnant women, the elderly, and the pediatric population.
Prothrombin Time ; Partial Thromboplastin Time

BACKGROUND: In order to achieve a maintenance level and to prevent hemorrhagic complications, regular monitoring of the INR is mandatory for patients on oral anticoagulation therapy (OAT). A point-of-care instrument for INR monitoring is convenient for users, but the accuracy of the results has been controversial, and so this calls for exact evaluation of the point-of-care instrument that is used for INR monitoring. METHODS: From Aug 2007 through Feb 2008, 85 patients on OAT among the all the patients who were admitted to Soonchunhyang University Bucheon Hospital were involved in this study. Parallel measurements of the PT INR were performed using a CoaguChek-XS and, a CA-7000 laboratory reference instrument and the results were analyzed. In addition, the patients' clinical data, including the diagnosis and the frequency and interval of the INR measurements, were also analyzed. RESULTS: Of the 85 patients, 25 were admitted more than once to undergo INR testing and the mean interval between testing was 8.6 weeks with 39% and 38% of the tests being less than INR 2 units with using the CoaguChek-XS and the reference method, respectively. The coefficients of variation of CoaguChek-XS were 4.50 and 2.45 for the high and low INR patients, respectively. An excellent correlation was found between the two methods with a R2 of 0.966 (p<0.001). Through Bland-Altman analysis, the mean INR difference between the two methods was 0.13 with the limit of agreement being -0.47 +0.72 with a 95% confidence interval. CoaguChek-XS was shown to overestimate the INR value for patients with an increasing INR, as compared to the reference method. CONCLUSION: CoaguChek-XS demonstrated great precision and accuracy for patients on OAT when compared to the laboratory INR results. Accordingly, the instrument should help to monitor the INR in the patients on OAT.
Avena ; Humans ; International Normalized Ratio ; Organothiophosphorus Compounds ; Prothrombin ; Prothrombin Time

BACKGROUND: Newly developed ACL9000 automatic coagulation analyzer was evaluated in measurement of prothrombin time(PT), activated partial thromboplastin time(aPTT) and fibrinogen. METHODS: We studied precision including withtin-run and between-day precision. Normal reference ranges for PT, aPTT and fibrinogen were obtained in 60 healthy normal controls. The heparin sensitivity for aPTT and heparin interference for PT and fibrinogen were also determined. Lastly ACL9000 was compared with another coagulation analyzer, MLA Electra 1600. RESULTS: Precision of PT, aPTT and fibrinogen were acceptable, mostly. The normal reference ranges were as followings: 10.7-12.4 sec for PT, 28.7-40.8 sec for aPTT and 165-468 mg/dL for fibrinogen. The ranges of aPTT were from 49.8 sec to 84.7 sec in therapeutic heparin concentration(0.2-0.4 IU/mL) and heparin interfered determination of PT and fibrinogen in high concentrations. The comparability between ACL9000 and MLA Electra 1600 was good in determinations of PT and fibrinogen but not in determination of aPTT. CONCLUSIONS: We concluded that the performance of ACL9000 was acceptable and ACL9000 would be a useful analyzer for routine coagulation tests.
Fibrinogen* ; Heparin ; Partial Thromboplastin Time ; Prothrombin ; Prothrombin Time ; Reference Values ; Thromboplastin

PURPOSE: The aim of this study was to help set the domestic guidelines for administration of antivenom to envenomated patients with snake. METHODS: This retrospective observation case series comprised 128 patients with a snake envenomation. The patients were divided into two groups according to the need for additional antivenom after the initial treatment strategy based on the traditional snakebite severity grading scale; one group recovered successfully with the initial treatment decision and did not require an additional antivenom (N=85) and the other group required an additional administration of antivenom later (N=43). RESULTS: The group requiring additional administration of antivenom showed a higher local effect score and traditional snakebite severity grading at presentation, a shorter prothrombin and activated partial prothrombin time, a higher frequency of rhabdomyolysis and disseminated intravascular coagulopathy, and longer hospitalization than the group that did not require an antivenom later. The most common cause of additional administration was the progression of local symptoms. The independent factor associated with the need for additional antivenom administration was a local effect scoring of pain score (odds ratio, 2.477; 95% confidence interval, 1.309 to 4.689). The optimal cut off value of local effect scoring of pain was 1.5 with 62.8% sensitivity and 71.8% specificity. CONCLUSION: The local effect scoring of pain should be considered when treating patients who are envenomated with a snake using the traditional snakebite severity scale. If the local effect scoring of pain is more than 2, an increase of antivenom should be considered and the patients should be assessed frequently.
Antivenins ; Hospitalization ; Humans ; Prothrombin ; Prothrombin Time ; Retrospective Studies ; Rhabdomyolysis ; Sensitivity and Specificity ; Snake Bites* ; Snakes* ; Venoms

PURPOSE: In patients with acetaminophen poisoning, clinical severities are partly based on the prothrombin time. In several conditions, N-acetylcysteine (NAC) infusion has been shown to lower the prothrombin index. Thus, we studied the effect of NAC on the prothrombin time in patients intoxicated with acetaminophen without hepatotoxicity. METHODS: From March 2000 to Aug 2004, we reviewed the medical records of 149 patients with a diagnosis of acetaminophen poisoning. After 88 patients had been excluded (29 had hepatocellular injury, 14 had a probable risk based on their normogram, and 45 had a missing prothrombin index value), 61 patients were included in the analysis. The prothrombin time was recorded before and serially during NAC treatment. RESULTS: The mean baseline prothrombin time was 99.1%, 99.3% after intravenous NAC infusion, and 74.0% at 8 hrs after initiation of NAC infusion. It decreased rapidly at 16 hrs, and reached a steady baseline state between 16 to 24 hrs. A rapid increase in the baseline time occurred after 2-3 days when the NAC infusion was stopped. After oral NAC treatment, it decreased rapidly from 8 to 16 hrs, and reached a steady baseline after 2 days. There was a rapid increase after 3~4 days when the NAC infusion was stopped. CONCLUSION: In patients with uncomplicated acetaminophen poisoning, the decrease in the prothrombin index might be misinterpreted as a sign of liver failure, leading to a prolonged treatment.
Acetaminophen* ; Acetylcysteine* ; Diagnosis ; Humans ; Liver Failure ; Medical Records ; Poisoning* ; Prothrombin Time* ; Prothrombin*

BACKGROUND AND OBJECTIVES: Patients on oral anticoagulation therapy (OAT) require regular monitoring of the prothrombin time (PT) and dosage adjustment to prevent thromboembolic diseases without the risk of hemorrhage. Portable self PT monitors have been recently developed because the standard PT measurements are complicated and take considerable time. This study compared the International normalized ratio (INR) results that were obtained with using the CoaguChek XS device (Roche Diagnostic, Mannheim, Germany) with those obtained using a standard laboratory method Sysmex CA-1500 (Sysmex Corporation, Kobe, Japan) in the patients on OAT and also a healthy control group. SUBJECTS AND METHODS: 100 outpatients on OAT and 20 healthy controls were enrolled on a volunteer basis after providing informed consent at the Dong-A University Hospital. The outpatients and the healthy control group provided us the INR measurements with using both the CoaguChek XS and the Sysmex CA-1500. RESULTS: The coefficients of variation for CoaguChek XS and Sysmex CA-1500 were less than 10%. The PT (INR) results of CoaguChek XS and Sysmex CA-1500 were 2.0+/-0.7 and 2.2+/-0.7, respectively (p<0.001). There was a good correlation between CoaguChek XS and Sysmex CA-1500 (r=0.974, p<0.001). On the regression analysis, the slope of the regression line was 0.9197 and the y-intercept was 0.0058. On the Bland-Altman analysis, the INR mean difference (bias) between the two methods (CoaguChek XS INR-Sysmex CA-1500 INR) was -0.2 and the limit of agreement was +0.168~-0.568. CONCLUSION: The measurement with using CoaguChek XS has high repeatability, rapid availability and good accuracy that are comparable to the standard laboratory method. Therefore, CoaguChek XS can be a valuable tool for the self-monitoring of patients on OAT.
Anticoagulants ; Avena ; Hemorrhage ; Humans ; Informed Consent ; International Normalized Ratio ; Outpatients* ; Prothrombin Time* ; Prothrombin* ; Volunteers

OBJECTIVE: This study aims to help set domestic guidelines for administration of antivenom to envenomated patients after snakebites. METHODS: This retrospective observational case series comprised 128 patients with snake envenomation. The patients were divided into two groups according to the need for additional antivenom after the initial treatment based on the traditional snakebite severity grading scale. One group successfully recovered after the initial treatment and did not need any additional antivenom (n=85) and the other needed an additional administration of antivenom (n=43). RESULTS: The group requiring additional administration of antivenom showed a higher local effect score and a traditional snakebite severity grade at presentation, a shorter prothrombin and activated partial prothrombin time, a higher frequency of rhabdomyolysis and disseminated intravascular coagulopathy, and longer hospitalization than the group that did not need additional antivenom. The most common cause for additional administration was the progression of local symptoms. The independent factor that was associated with the need for additional antivenom was the local effect pain score (odds ratio, 2.477; 95% confidence interval, 1.309 to 4.689). The optimal cut-off value of the local effect pain score was 1.5 with 62.8% sensitivity and 71.8% specificity. CONCLUSION: When treating patients who are envenomated by a snake, and when using the traditional snakebite severity scale, the local effect pain score should be taken into account. If the score is more than 2, additional antivenom should be considered and the patient should be frequently assessed.
Antivenins ; Hospitalization ; Humans ; Prothrombin ; Prothrombin Time ; Retrospective Studies ; Rhabdomyolysis ; Sensitivity and Specificity ; Snake Bites* ; Snakes ; Venoms

BACKGROUND: Prothrombin time (PT) measurement is an important test for screening blood coagulation disorders and monitoring anticoagulant therapy. In this study, we evaluated the analytical performance of HemosIL ReadiPlasTin (Instrumentation Laboratory, USA), a liquid reagent for PT measurement. METHODS: The precision of HemosIL ReadiPlasTin was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) EP5-A3 guidelines. Further, comparison with HemosIL RecombiPlasTin 2G (Instrumentation Laboratory, USA) was made according to the CLSI EP9-A3 guidelines. The reference intervals were established according to the CLSI C28-A3 guidelines. RESULTS: The coefficient of variation values for repeatability and total imprecision at two levels of control materials were lower than 1.1% and 3.4%, respectively. The performance of HemosIL ReadiPlasTin was comparable to that of HemosIL RecombiPlasTin 2G, with a high correlation (r=0.996). The reference interval for normal subjects was 10.4–13.3 seconds. CONCLUSIONS: HemosIL ReadiPlasTin showed an acceptable degree of imprecision and its performance showed high correlation with that of a conventional reagent. Therefore, it is expected to be useful for PT measurement in clinical laboratories.
Blood Coagulation Disorders ; Blood Coagulation Tests ; Mass Screening ; Prothrombin Time ; Prothrombin ; Thromboplastin

BACKGROUND: Hemorrhagic transformation (HT) of stroke is a disastrous complication in patients with infective endocarditis (IE). In patients with mechanical heart valves complicated by IE, physicians struggle with the appropriateness of anticoagulation administration given the risk of thromboembolism and HT of stroke. In this study, we aimed to define predictive parameters of HT of stroke in patients with prosthetic valve endocarditis (PVE). METHODS: This study was a multicenter, retrospective design. We recruited from 7 institutions a total of 111 patients diagnosed with PVE during May, 2011 to April, 2012. RESULTS: Complication of stroke was seen in 26/111 patients (23%), and HT of stroke was seen in 11/111 patients (10%). Most patients with HT (9/11, 82%) had supratherapeutic prothrombin times. However, there were no significant differences in clinical and laboratory values between PVE patients without stroke and those patients who had a stroke and with or without concurrent HT. Furthermore, echocardiographic parameters also did not show significant between-group differences. CONCLUSION: Even though this was a multicenter study, a limited number of patients was identified and may explain the negative results seen here. However, a large number of PVE patients with stroke also developed HT. Therefore, further studies to define predictive parameters of HT should be implemented in a larger population.
Endocarditis* ; Heart Valves ; Humans ; Prothrombin Time ; Retrospective Studies ; Stroke* ; Thromboembolism