Impact of Protocolized Pharmacist Intervention on Critical Activated Partial Thromboplastin Time Values With Heparin Infusions

2021 ◽  
pp. 875512252110319
Author(s):  
Rachelle Barry ◽  
Craig A. Stevens ◽  
Trina Huynh ◽  
Dmitri Lerner
Keyword(s):  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Academic Research ◽  
Pharmacist Intervention ◽  
Activated Partial Thromboplastin Time ◽  
Efficacy And Safety ◽  
Time In Therapeutic Range ◽  
Institutional Review ◽  
Secondary Endpoints ◽  
Research Consortium

Background: Unfractionated heparin (UFH) infusions are commonly managed with nurse-driven nomograms titrated to activated partial thromboplastin time (aPTT). In some patients, anti-Xa values may be more appropriate measures of anticoagulation. At the present institution, an update to the nurse-driven aPTT nomogram requires pharmacist notification and clinical assessment for critically supratherapeutic aPTT results. Objective: The purpose of this study was to evaluate the efficacy and safety of the nomogram update. Methods: A single-center, retrospective, pre-post analysis was conducted in patients treated with UFH who experienced a critical aPTT during the 6 months preceding and following the nomogram update. Patients with erroneous critical aPTT results were excluded. The primary endpoint was the time in therapeutic range (Rosendaal method) from the first critical aPTT until UFH discontinuation. Secondary endpoints included the proportion of patients transitioned to anti-Xa monitoring and the incidence of Bleeding Academic Research Consortium (BARC) 2, 3, 5 bleeding. Data were analyzed by the χ2 test. The study was institutional review board approved. Results: Of 277 UFH infusions, 142 belonged to the pre-implementation group and 135 to the post-implementation group. Baseline aPTTs were similar between the 2 groups. Time in therapeutic range was 58.1% versus 62.4% of between groups ( P = .467). UFH was transitioned to pharmacist-driven anti-Xa monitoring in 16.2% versus 40.3% of patients ( P < .001). BARC 2, 3, 5 bleeding occurred in 23.2% versus 13.4% of patients ( P < .001). Conclusions: Application of these data suggest improved safety and efficacy outcomes with directed pharmacist management of UFH in patients with critically elevated aPTTs.

Efficacy of ethanol ablation for treatment of benign cystic thyroid nodules: the first hospital-based study in Vietnam

MedPharmRes ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 18-22
Author(s):  
Van Bang Nguyen ◽  
Van Vy Hau Nguyen ◽  
Binh Thang Tran ◽  
Chi Van Le
Keyword(s):  
Thyroid Nodules ◽  
Multiple Logistic Regression Analysis ◽  
Volume Reduction ◽  
Efficacy And Safety ◽  
Inclusion Criteria ◽  
Ethanol Ablation ◽  
Institutional Review ◽  
Thyroid Cyst ◽  
Secondary Endpoints ◽  
Written Informed Consent

Background: In Vietnam, surgery or aspiration is preferred to treat thyroid cysts however each of them still have limitations. Purposes of this study were to evaluate the efficacy and safety of ethanol ablation in treating thyroid cysts and determine factors that predict the outcome of treatment. Methods: This prospective study was approved by the Ethics Committee of the Institutional Review Board of Family hospital and written informed consent for procedures was obtained. From May 2018 to March 2019, 23 patients who underwent treatment for thyroid cysts by EA were enrolled in this study and were followed up for 1 month at Family hospital. The primary endpoint was efficient after one month as the volume reduction ratio was ≥ 50%. Secondary endpoints were improvements in symptoms, cosmetic scores, and safety. Multiple logistic regression analysis was used. Results: In the finding, from May 2018 to March 2019, only 17 patients who matched inclusion criteria were included in the analyst, including 7 purely thyroid cysts, and 10 predominantly cystic nodules. Mean volume decreased significantly from 5.21 ± 3.37 ml to 2.35 ± 2.52 ml in corresponding to 52.87% of volume reduction with p < 0.05. Ethanol ablation (EA) success rate was 52.90% after 1 month. Symptoms and cosmetic scores were improved significantly. The thyroid function was constant. No adverse events occurred. Purely thyroid cyst was a predictive factor contributing to the success of EA. Conclusion: EA seems likely to be a safe and an efficient therapy for patients who had purely or predominantly cystic thyroid nodules.

Use of the Activated Partial Thromboplastin Time in the Control of Heparin Administration

1966 ◽  
Vol 12 (5) ◽  
pp. 263-268 ◽  
Author(s):  
Jane G Lenahan ◽  
Sheldon Frye ◽  
George E Phillips
Keyword(s):  
Therapeutic Range ◽  
Whole Blood ◽  
Partial Thromboplastin Time ◽  
Blood Clotting ◽  
Heparin Therapy ◽  
Activated Partial Thromboplastin Time ◽  
Clotting Time ◽  
Heparin Administration ◽  
Blood Clotting Time

Abstract The activated partial thromboplastin time (APTT) was compared to the whole blood clotting time (WBCT) as a control of heparin administration. The APTT was shown to be a sensitive system for the control of heparin therapy, with the added advantage that the blood can be drawn and taken to the laboratory for assay. The effective therapeutic range in man remains to be established.

Results of a Survey of Hospital Coagulation Laboratories in the United States, 2001

2005 ◽  
Vol 129 (1) ◽  
pp. 47-60
Author(s):  
Shahram Shahangian ◽  
Ana K. Stanković ◽  
Ira M. Lubin ◽  
James H. Handsfield ◽  
Mark D. White
Keyword(s):  
United States ◽  
Prothrombin Time ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Sampling Rate ◽  
The United States ◽  
Activated Partial Thromboplastin Time ◽  
Sampling Frame ◽  
American Hospital ◽  
American Hospital Association

Abstract Context.—Coagulation and bleeding problems are associated with substantial morbidity and mortality, and inappropriate testing practices may lead to bleeding or thrombotic complications. Objective.—To evaluate practices reported by hospital coagulation laboratories in the United States and to determine if the number of beds in a hospital was associated with different practices. Design.—From a sampling frame of institutions listed in the 1999 directory of the American Hospital Association, stratified into hospitals with 200 or more beds (“large hospitals”) and those with fewer than 200 beds (“small hospitals”), we randomly selected 425 large hospitals (sampling rate, 25.6%) and 375 small hospitals (sampling rate, 8.8%) and sent a survey to them between June and October 2001. Of these, 321 large hospitals (75.5%) and 311 small hospitals (82.9%) responded. Results.—An estimated 97.1% of respondents reported performing some coagulation laboratory tests. Of these, 71.6% reported using 3.2% sodium citrate as the specimen anticoagulant to determine prothrombin time (81.3% of large vs 67.7% of small hospitals, P &lt; .001). Of the same respondents, 45.3% reported selecting thromboplastins insensitive to heparin in the therapeutic range when measuring prothrombin time (59.4% of large vs 39.8% of small hospitals, P &lt; .001), and 58.8% reported having a therapeutic range for heparin (72.9% of large vs 53.2% of small hospitals, P &lt; .001). An estimated 96.3% of respondents assayed specimens for activated partial thromboplastin time within 4 hours after phlebotomy, and 89.4% of respondents centrifuged specimens within 1 hour of collection. An estimated 12.1% reported monitoring low-molecular-weight heparin therapy, and to do so, 79% used an assay for activated partial thromboplastin time (58% of large vs 96% of small hospitals, P = .001), whereas 38% used an antifactor Xa assay (65% of large vs 18% of small hospitals, P = .001). Conclusions.—Substantial variability in certain laboratory practices was evident. Where significant differences existed between the hospital groups, usually large hospitals adhered to accepted practice guidelines to a greater extent. Some reported practices are not consistent with current recommendations, showing a need to understand the reasons for noncompliance so that better adherence to accepted standards of laboratory practice can be promoted.

Interlaboratory Precision in the Monitoring of Unfractionated Heparin Using the Anti-Factor Xa-Correlated Activated Partial Thromboplastin Time

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 435-435
Author(s):  
Adam Cuker ◽  
Beverly Ptashkin ◽  
Barbara A. Konkle ◽  
Steven W. Pipe ◽  
Herbert C. Whinna ◽  
...  
Keyword(s):  
Unfractionated Heparin ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Factor Xa ◽  
Correlation Method ◽  
Activated Partial Thromboplastin Time ◽  
Laboratory Monitoring ◽  
Upper Limit ◽  
Accuracy And Precision ◽  
Therapeutic Category

Abstract Although the activated partial thromboplastin time (aPTT) remains the most widely used method for monitoring unfractionated heparin (UFH) therapy, it is affected by a number of preanalytic, analytic, and biological variables, which undermine both its accuracy and precision. In an effort to improve the accuracy and precision of laboratory monitoring of UFH, the College of American Pathologists (CAP) and the American College of Chest Physicians (ACCP) have issued guidelines recommending that the therapeutic range of the aPTT be defined in each laboratory through correlation with a direct measurement of heparin activity such as the factor Xa inhibition assay (anti-FXa). Whether and to what extent this approach enhances the precision of UFH monitoring has not been reported. We conducted a cross-validation study among 4 CAP-accredited coagulation laboratories to assess the interlaboratory precision of the anti-FXa-correlation method. An aPTT and anti-FXa were performed in each laboratory on plasma samples from 44 inpatients receiving UFH. Interlaboratory precision of the anti-FXa-correlation method was compared to that of the traditional 1.5–2.5 times the upper limit of normal (ULN) method for defining the therapeutic aPTT range. Modest to poor intralaboratory correlation between the aPTT and anti-FXa was observed in each of the 4 laboratories. The coefficients of determination (R2) ranged from 0.1962 to 0.6964. In accordance with CAP guidelines, the anti-FXa-derived therapeutic aPTT range was defined by linear regression corresponding to a range of anti-FXa activity of 0.3 – 0.7 units/ml. In each laboratory, the range defined by this method was broader than that defined using the ULN method. In 3 of the laboratories, the therapeutic range defined by the anti-FXa-correlation method extended more than 20 seconds beyond the upper limit of the therapeutic range defined by the ULN approach. Based on the laboratory-specific therapeutic ranges defined by both methods, samples were segregated into therapeutic category [i.e. below therapeutic (BT), therapeutic (T), or above therapeutic (AT)]. Using the ULN method, there was agreement among all 4 laboratories regarding the therapeutic category in 22 (50%) samples, whereas consensus was achieved in only 7 (16%) samples with the anti-FXa-correlation method. Furthermore, 3 (7%) samples were simultaneously determined to be BT and AT in different laboratories by the anti-FXa-correlation method, suggesting that the dose of UFH might be increased in one center and decreased in another for the same patient encounter. This striking discrepancy was not observed with the ULN method. In conclusion, the anti-FXa-correlation method for defining the therapeutic range of the aPTT does not enhance the interlaboratory precision of UFH laboratory monitoring and may be inferior to the ULN method in this regard. Clinical studies are needed to assess the impact of these findings on patient safety.

The Therapeutic Range for Heparin Therapy: Relationship between Six Activated Partial Thromboplastin Time Reagents and Two Heparin Assays

1996 ◽  
Vol 75 (05) ◽  
pp. 734-739 ◽  
Author(s):  
S Kitchen ◽  
F E Preston
Keyword(s):  
Unfractionated Heparin ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Warfarin Therapy ◽  
Normal Subjects ◽  
Heparin Therapy ◽  
Thromboembolic Disease ◽  
Activated Partial Thromboplastin Time ◽  
Therapy Relationship ◽  
The Relationship

SummaryThe activated partial thromboplastin time (APTT) is the most commonly used test for laboratory monitoring of unfractionated heparin therapy. Since there are differences between APTT reagents in respect of responsiveness to heparin the widely used therapeutic range of 1.5-2.5 (APTT ratios) may not be appropriate for all reagents.The aim of this study was to assess the relationship between 6 different APTT reagents using a manual technique, 2 of these reagents used in combination with a coagulometer, a heparin assay by protamine titration and a chromogenic anti-Xa assay. Samples from 42 patients treated with unfractionated heparin for thromboembolic disease were studied, 12 of whom were receiving warfarin therapy with International Normalised Ratios (INR) of >1.3.For normal subjects, APTT results were highly dependent on the method used and statistically significant differences were noted. The ratio of patient to mean normal APTT was calculated for each APTT method. When 30 samples from heparinised patients (with INRs of <1.3) were analysed manually, the APTT ranges equivalent to 0.2-0.4 u/ml heparin by protamine titration (by regression analysis) were 1.6-1.9 for Boehringer reagent (the least responsive) up to 2.2-2.9 for Instrumentation Laboratory reagent (the most responsive). The concentration of heparin associated on average with APTT ratios of 1.5-2.5 varied approximately twofold to threefold between reagents.

scholarly journals Use of a Fixed Activated Partial Thromboplastin Time Ratio to Establish a Therapeutic Range for Unfractionated Heparin

2001 ◽  
Vol 161 (3) ◽  
pp. 385 ◽  
Author(s):  
Shannon M. Bates ◽  
Jeffrey I. Weitz ◽  
Marilyn Johnston ◽  
Jack Hirsh ◽  
Jeffrey S. Ginsberg
Keyword(s):  
Unfractionated Heparin ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Activated Partial Thromboplastin Time ◽  
Time Ratio

The Optimum Number and Types of Plasma Samples Necessary for an Accurate Activated Partial Thromboplastin Time–Based Heparin Therapeutic Range

2013 ◽  
Vol 137 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Richard A. Marlar ◽  
Jana Gausman
Keyword(s):  
Unfractionated Heparin ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Ex Vivo ◽  
Activated Partial Thromboplastin Time ◽  
Optimum Number ◽  
Extrinsic Factors ◽  
Absolute Minimum ◽  
Sample Number ◽  
Minimum Number

Context.—Monitoring of unfractionated heparin therapy by activated partial thromboplastin time (aPTT) using the ex vivo method for determining the aPTT-based heparin therapeutic range (HTR) is the standard of practice. Many intrinsic and extrinsic factors influence its accuracy. Objective.—To investigate the optimum number and types of samples acceptable for an accurate ex vivo HTR determination. Design.—Values from patients receiving unfractionated heparin are used to determine the HTR by published guidelines. The number and types of samples are changed to investigate the effect on HTR parameters. Results.—Absolute minimum number of samples for an accurate HTR is 20, with fewer than 10% of the samples from the same patient or 50% of the samples with international normalized ratio of 1.3 to 1.5. Conclusions.—The ex vivo HTR method is the best protocol currently available; however, the number of samples used affects its accuracy. The optimum number of samples is 30 or more but the absolute minimum number is 20. In addition, limitation of specific sample types also affects the HTR parameters. An inaccurate HTR may be calculated if inappropriate sample number or types of samples are used.

scholarly journals Evaluation of Bivalirudin’s Effect on International Normalized Ratio to Determine an Appropriate Strategy for Transitioning to Warfarin

2018 ◽  
Vol 34 (3) ◽  
pp. 117-122
Author(s):  
Andrea Fetea ◽  
Brian E. Gulbis ◽  
Andrea C. Hall
Keyword(s):  
Primary Endpoint ◽  
Major Bleeding ◽  
Partial Thromboplastin Time ◽  
International Normalized Ratio ◽  
Activated Partial Thromboplastin Time ◽  
Thrombin Inhibitors ◽  
Direct Thrombin Inhibitors ◽  
Limited Data ◽  
Heparin Induced Thrombocytopenia ◽  
Secondary Endpoints

Background: Direct thrombin inhibitors are recommended in confirmed or suspected heparin-induced thrombocytopenia. False elevation of the international normalized ratio (INR) occurs with these agents making bridging to warfarin challenging. There is limited data regarding bivalirudin’s effect on INR. Objective: To evaluate bivalirudin’s effect on the INR and determine a strategy for transitioning to warfarin. Methods: This was a retrospective observational study. Included patients were >18 years old receiving primary bridging therapy with overlapping bivalirudin and warfarin for at least 72 hours. Patients with administration of alternate anticoagulants during the transition interval or active major bleeding within 48 hours prior to bivalirudin initiation were excluded. The primary endpoint was to determine the effect on INR at first therapeutic activated partial thromboplastin time after bivalirudin initiation and prior to warfarin initiation. Secondary endpoints included change in INR 12 and 24 hours after bivalirudin initiation, change in INR 4 hours after bivalirudin cessation, and incidence of major bleeding or new thrombotic events. Results: Thirty-four patients met study criteria. For the primary endpoint, the change in INR at first therapeutic activated partial thromboplastin time was 0.37 (range = 0.28-0.48), which occurred at 8.4 hours (range = 4.6-14.2; n = 14). INR increased at 12 and 24 hours by a median of 0.55 and 0.5 from baseline, respectively. Median change in INR 4 to 8 hours post-bivalirudin cessation was −0.48. Conclusion: Targeting an INR > 2.5 when bridging to warfarin will account for this false elevation and maintain an INR above 2.0 on bivalirudin discontinuation.

scholarly journals Protocolled Redefinition of the Therapeutic Range for Unfractionated Heparin: Lost in Translation?

2016 ◽  
Vol 24 (1) ◽  
pp. 164-171 ◽  
Author(s):  
Karlien L. M. Coene ◽  
Fedde van der Graaf ◽  
Daan van de Kerkhof
Keyword(s):  
Unfractionated Heparin ◽  
Therapeutic Range ◽  
Partial Thromboplastin Time ◽  
Treatment Duration ◽  
Patient Characteristics ◽  
Calibration Method ◽  
Activated Partial Thromboplastin Time ◽  
Ongoing Debate ◽  
Monitoring Protocols ◽  
Lost In Translation

Background: Protocolled treatment with unfractionated heparin (UFH) is a subject of ongoing debate. Even though international guidelines prescribe calibration of the activated partial thromboplastin time (aPTT) to 0.3 to 0.7 U/mL anti-Xa activity to establish an UFH therapeutic range, evidence for this approach remains scarce. In this study, we evaluated different strategies to delineate the UFH therapeutic range and analyzed the effects on patient therapeutic classification. Methods: In 109 patient samples, the aPTT was measured with 2 different reagents, both of which used mechanical clot detection. The UFH therapeutic range was determined using 3 previously described methods: calibration of the aPTT to 0.3 to 0.7 U/mL anti-Xa activity, application of 1.5 to 2.5 times the control aPTT, or using 0.3 to 0.7 U/mL anti-Xa activity directly. We also applied the UFH therapeutic range of a second hospital to our patient population. Results: Application of the guideline-prescribed anti-Xa calibration method would result in patients receiving increased UFH dosage in comparison to our previous UFH nomogram. Between-method and between-laboratory variations in aPTT and anti-Xa activity assays are a likely cause of these discrepancies. Additionally, we show that individual patient characteristics, such as weight and UFH treatment duration, likely contribute to the discordance between different strategies to establish an UFH therapeutic range. Conclusion: No consensus is reached between different strategies to define the UFH therapeutic range, which could result in relevant differences in UFH doses applied in patients. Clinicians and laboratory specialists should critically evaluate UFH monitoring protocols and be aware of their shortcomings.

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