Use of Venipuncture Blood Sample for INR Testing on a Point of Care Machine.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4159-4159
Author(s):  
Mandeep S. Dhami ◽  
Anca Bulgaru ◽  
K. Jagathambal ◽  
Dinesh Kapur ◽  
Francine Norris ◽  
...  

Abstract Point of care (POC) testing of International Normalized Ratio (INR) for monitoring warfarin therapy is rapidly becoming procedure of choice for patients requiring long term oral anticoagulation. This method allows for fingerstick blood sample to be used for INR testing at the point of service with immediate dose modification as needed. Most patients prefer a fingerstick method for blood draw to venipuncture. It is not known if venipuncture blood sample can be used for testing on POC machines. A significant number of patients in an oncology practice need additional laboratory testing on the same day as INR testing. These patients therefore get a fingerstick for POC INR testing and a venipuncture for other tests. We compared results of INR from venipuncture sample run on a POC machine (CoaguChek monitor) using CoaguChek test strips (ISI-2.0) with the INR performed on MDA analyzer (ISI-2.0). Blood samples from 24 patients on warfarin therapy were drawn from antecubital vein by a clean stick in a 10 cc plastic syringe. A drop of blood was immediately placed on the CoaguCheck test strip. Next the same blood sample was used to fill a 3.2% sodium citrate tube for testing on MDA analyzer. Results were analyzed using regression analysis; the correlation coefficient (r), slope and intercept were determined and following graph of the regression analysis was generated (see figure 1). Conclusions: These results show a good correlation (r-value> 0.9) between the results of INR obtained on CoaguChek POC machine and the MDA analyzer using venipuncture blood sample. The preferred method to obtain blood sample for POC INR monitoring must remain fingerstick sample as per manufacturer’s recommendations. However, for those patients who need more than one blood sample done on the same day, a venipuncture sample as described above gives acceptable results when tested on CoaguCheck machine. Figure Figure

2008 ◽  
Vol 74 (9) ◽  
pp. 858-861 ◽  
Author(s):  
Michael Kalina ◽  
Glen Tinkoff ◽  
Adebayo Gbadebo ◽  
Paula Veneri ◽  
Gerard Fulda

Trauma patients on prescribed warfarin therapy sustaining intracranial hemorrhage can be difficult to manage. Rapid normalization of coagulopathy is imperative to operative intervention and may affect outcomes. To identify and expedite warfarin reversal, we designed a protocol to administer a prothrombin complex concentrate. A Proplex T protocol was instituted in May 2004. It dictated that trauma patients with an International Normalized Ratio (INR) greater than 1.5, history of prescribed warfarin therapy, and intracranial hemorrhage on CT scan receive a prothrombin complex concentrate for reversal of their coagulopathy. Neither the protocol nor the factor concentrate was validated for use in this subset of trauma patients; therefore, adherence to the protocol and use of the factor concentrate was not mandatory. Patients not administered the prothrombin complex concentrate received vitamin K and fresh-frozen plasma. The protocol resulted in an increased number of patients receiving Proplex T (54.3% vs 35.4%, P = 0.047). Protocol patients had improved times to normalization of INR (331.3 vs 737.8 minutes, P = 0.048), number of patients with reversal of coagulopathy (73.2% vs 50.9%, P = 0.026), and time to operative intervention (222.6 vs 351.3 minutes, P = 0.045) compared with control subjects. There were no differences in intensive care unit (ICU) days, hospital days, or mortality. The Proplex T protocol increased the number of patients who received prothrombin complex concentrate, provided rapid normalization of INR, and improved time to operative intervention.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Eiji Iwata ◽  
Akira Tachibana ◽  
Junya Kusumoto ◽  
Naoki Takata ◽  
Takumi Hasegawa ◽  
...  

Abstract Background Various antibiotics and analgesics have been reported to interact with warfarin. Reports that investigate the effects of medication taken for just a few days during tooth extraction on the prothrombin time-international normalized ratio are rare. Methods A total of 110 patients receiving long-term stable warfarin therapy underwent tooth extraction without interruption of warfarin treatment. INR values were measured 1 month before the tooth extraction, the day of the extraction, and 1 week after the extraction. We investigated the changes in INR values between the day of extraction and 1 week after extraction, as well as the various risk factors for increases in INR values. Results Before and after tooth extraction, the number of patients taking cefcapene pivoxil, amoxicillin, and azithromycin was 57, 36, and 8, respectively. Nine patients were administered ampicillin before tooth extraction and received amoxicillin after their tooth extraction. One week after tooth extraction, the INR values increased beyond the therapeutic range in 3 out of 110 patients (2.7%). The INR values before tooth extraction in these three patients were close to 3.0. The INR value increased by more than twice as much in 1 out of 110 patients (0.9%). Conclusion Our results suggest that prophylactic antibiotic administration has little effect on INR values when patients on stable warfarin therapy undergo tooth extraction. Surgeons have to take attention if the patients whose INR values are close to 3.0 before their extraction.


Biomedicine ◽  
2021 ◽  
Vol 41 (3) ◽  
pp. 682-685
Author(s):  
Kanat kyzy Bazira ◽  
Nazgul Kinderbaeva ◽  
Gulnora Karataeva ◽  
Sabira Mamatova ◽  
Ulan Kundashev ◽  
...  

Introduction: Anticoagulant therapy can prevent adverse outcomes of Atrial fibrillation (AF), reducing the risk of stroke by 64% and death by 25%. The present study aimed to assess treatment adherence in elderly patients with non-valvular atrial fibrillation (NVAF) who were prescribed the vitamin K antagonist warfarin.   Materials and methods: In the present retrospective study, we analyzed the medical records of 202 elderly outpatients with NVAF aged between 65 and 74 years (mean ± SD: 68.7 ± 10.2 years).    Results: Problems associated with warfarin arose throughout the follow-up period. After 1 month of treatment, the number of patients taking warfarin had decreased to 71.3% of all patients; less than half of the patients (46%) were still taking the drug. In subsequent periods, the number continued to decrease; of all patients who had been prescribed warfarin with periodic international normalized ratio (INR) control, only 19 (9.4%) remained after 1 year. Our study revealed inadequate anticoagulation therapy in elderly patients, probably because most patients refused warfarin therapy because they could not control their INR. Moreover, significantly more rural residents than urban residents refused therapy (48 vs. 22; p < 0.05). Doctors underprescribed anticoagulants because they feared hemorrhagic complications in their patients.   Conclusion: The results of the present study showed that anticoagulants were underprescribed at the outpatient stage in centers of family medicine in our country. The main drug of choice for specialists remains warfarin, which only provides adequate therapy in a small number of patients (9.4%).


2020 ◽  
Author(s):  
Eiji Iwata ◽  
Akira Tachibana ◽  
Junya Kusumoto ◽  
Naoki Takata ◽  
Takumi Hasegawa ◽  
...  

Abstract Background: Various antibiotics and analgesics have been reported to interact with warfarin. Reports that investigate the effects of medication taken for just a few days during tooth extraction on the prothrombin time-international normalized ratio (PT-INR) are rare.Methods: A total of 110 patients receiving long-term stable warfarin therapy underwent tooth extraction without interruption of warfarin treatment. INR values were measured one month before the tooth extraction, the day of the extraction, and one week after the extraction. We investigated the changes in INR values between the day of extraction and one week after extraction, as well as the various risk factors for increases in INR values.Results: Before and after tooth extraction, the number of patients taking cefcapene pivoxil, amoxicillin, and azithromycin was 57, 36, and 8, respectively. Nine patients were administered ampicillin before tooth extraction and received amoxicillin after their tooth extraction. One week after tooth extraction, the INR values increased beyond the therapeutic range in 3 out of 110 patients (2.7%). The INR values before tooth extraction in these three patients were close to 3.0. The INR value increased by more than twice as much in 1 out of 110 patients (0.9%).Conclusion: Our results suggest that prophylactic antibiotic administration has little effect on INR values when patients on stable warfarin therapy undergo tooth extraction. Surgeons have to take attention if the patients whose INR values are close to 3.0 before their extraction.


2020 ◽  
Author(s):  
Eiji Iwata ◽  
Akira Tachibana ◽  
Junya Kusumoto ◽  
Naoki Takata ◽  
Takumi Hasegawa ◽  
...  

Abstract Background: Various antibiotics have been reported to interact with warfarin. Reports to have investigated the effects of prophylactic antibiotic administration for tooth extraction in patients taking warfarin on the prothrombin time-international normalized ratio (PT-INR) are rare.Methods: A total of 110 patients receiving long-term stable warfarin therapy underwent tooth extraction without interruption of warfarin treatment. INR values were measured one month before the tooth extraction, the day of the extraction, and one week after the extraction. We investigated the changes of INR values between the day of extraction and one week after the extraction, as well as the various risk factors for increases in INR values.Results: Before and after tooth extraction, the number of patients taking cefcapene pivoxil, amoxicillin, and azithromycin was 57, 36, and 8, respectively. Nine patients were administered ampicillin before tooth extraction and received amoxicillin after their tooth extraction. One week after tooth extraction, the INR values increased beyond the therapeutic range in 3 out of 110 patients (2.7%). The INR values before tooth extraction in these three patients were close to 3.0. The INR value increased by more than twice as much in 1 of 110 patients (0.9%).Conclusion: Our results suggest that prophylactic antibiotic administration has little effect on their INR values when patients on stable warfarin therapy undergo tooth extraction. Surgeons have to take attention if the patients whose INR values are close to 3.0 before their extraction.


2021 ◽  
pp. 875512252110341
Author(s):  
Sahimi Mohamed ◽  
Chan Mei Fong ◽  
Yew Jie Ming ◽  
Ahlam Naila Kori ◽  
Sopian Abdul Wahab ◽  
...  

Background: he number of patients on warfarin therapy is rising steadily. Although warfarin is beneficial, it carries a high risk of bleeding, especially if the international normalized ratio (INR) values exceed 3.0. Currently, no warfarin initiation regimens have been developed for the Asian population, especially for Malaysians. Objective: This article describes the efficacy and safety of a new initiation regimen for warfarin among warfarin-naive patients. Method: Data were retrospectively collected from the ambulatory and inpatient settings. Results: A total of 165 patients who each had a target INR of 2.0 to 3.0 were included in the study. The mean age was 57.2 years and 94 patients were male. A total of 108 patients used Regimen 1 (5 mg/5 mg/3mg) and the rest of the patients used Regimen 2 (5 mg/3 mg/3 mg). Most patients used warfarin either for atrial fibrillation (52.1%) or for venous thromboembolism (29.7%). Overall, 88 of the patients had INR values above 50% from the baseline on Day 4. Additionally, 13 patients had INR values of >3.2, which required withholding and lower dose of warfarin. The predicted weekly maintenance warfarin dose (23 ± 0.5 mg/week) was found to have correlated closely with the actual maintenance dose (22.8 ± 0.5 mg/week; r2 = 0.75). Nearly two thirds (70.3%) of the patients achieved the target INR on Day 11. Conclusion: The warfarin initiation regimens in this study was simple, safe, and suitable to be used in both ambulatory and inpatient settings for managing warfarin therapy.


2020 ◽  
Author(s):  
Eiji Iwata ◽  
Akira Tachibana ◽  
Junya Kusumoto ◽  
Naoki Takata ◽  
Takumi Hasegawa ◽  
...  

Abstract Background: Various antibiotics and analgesics have been reported to interact with warfarin. Reports that investigate the effects of medication taken for just a few days during tooth extraction on the prothrombin time-international normalized ratio (PT-INR) are rare. Methods: A total of 110 patients receiving long-term stable warfarin therapy underwent tooth extraction without interruption of warfarin treatment. INR values were measured one month before the tooth extraction, the day of the extraction, and one week after the extraction. We investigated the changes of INR values between the day of extraction and one week after the extraction, as well as the various risk factors for increases in INR values.Results: Before and after tooth extraction, the number of patients taking cefcapene pivoxil, amoxicillin, and azithromycin was 57, 36, and 8, respectively. Nine patients were administered ampicillin before tooth extraction and received amoxicillin after their tooth extraction. One week after tooth extraction, the INR values increased beyond the therapeutic range in 3 out of 110 patients (2.7%). The INR values before tooth extraction in these three patients were close to 3.0. The INR value increased by more than twice as much in 1 of 110 patients (0.9%).Conclusion: When a tooth extraction is performed in patients taking warfarin, certain factors could increase the INR, such as interaction between warfarin and antibiotics or analgesics, post-extraction inflammation or infection, and eating disorders due to post-extraction pain. However, our results suggest that it has little effect on the INR values one week after extraction.


2000 ◽  
Vol 34 (5) ◽  
pp. 567-572 ◽  
Author(s):  
William E Dager ◽  
Jennifer M Branch ◽  
Jeffrey H King ◽  
Richard H White ◽  
Richard S Quan ◽  
...  

OBJECTIVE: To determine the effect of daily consultation by a team of hospital pharmacists on the accuracy and rapidity of optimizing warfarin therapy. DESIGN: Comparison of a historical control cohort with a prospective cohort matched for treatment indication. SETTING: A 400-bed university teaching hospital. PATIENTS: Sixty consecutive patients hospitalized in 1992 and starting warfarin for the first time, with anticoagulation therapy managed by physicians, were compared with 60 patients matched for warfarin indication hospitalized in 1995, but with anticoagulation therapy managed with pharmacy consultation. RESULTS: Pharmacist management of initial warfarin therapy resulted in a significant reduction in the length of hospitalization compared with physician dosing, from 9.5 ± 5.6 days to 6.8 ± 4.4 days (p = 0.009). The number of patients and patient-days with international normalized ratio (INR) values >3.5 were reduced by pharmacist dosing from 37 patients and 142 days to 16 patients and 29 days, respectively (p < 0.001). Similarly, the number of patients and patient-days with INR >6.0 were reduced from 20 patients and 50 days to two patients and six days, respectively (p < 0.001). There were six documented bleeding complications in 1992 compared with one in 1995 (p = 0.11). The mean INR at discharge was significantly lower in the pharmacy surveillance group, 2.6 ± 0.58, compared with the physician cohort, 3.3 ± 2.1 (p = 0.07). Readmissions after discharge due to bleeding or recurrent thrombosis were reduced from five (at 1 mo) and 10 (at 3 mo) to two and five readmissions, respectively, by pharmacist intervention (p = 0.43). The number of patients with concurrently prescribed drugs known to significantly interact with warfarin was significantly lower (6 vs. 13; p = 0.02) in the pharmacy surveillance group. CONCLUSIONS: Among patients starting warfarin for the first time, daily consultation by a pharmacist significantly decreased the length of hospital stay and the number of patients who received excessive anticoagulation therapy. These findings translate into improved quality of care and potentially significant cost savings.


2003 ◽  
Vol 37 (6) ◽  
pp. 799-803 ◽  
Author(s):  
Gregory W Roberts ◽  
Trine Helboe ◽  
Cathrine BM Nielsen ◽  
Alex S Gallus ◽  
Iwona Jensen ◽  
...  

OBJECTIVE: To examine the time taken to reach a stable international normalized ratio (INR), as well as the incidence of overanticoagulation of an age-adjusted warfarin initiation protocol. METHODS: Inpatients and outpatients commencing warfarin therapy at 2 teaching hospitals were dosed according to the age-adjusted protocol. Data were collected prospectively. MAIN OUTCOME MEASURES: Time to reach a stable INR of 2–3 and the number of patients experiencing an INR ≥4 during the first week of warfarin therapy. RESULTS: Seventy-three patients were assessed; at the completion of the 4-day titration protocol, 63% had achieved a stable INR. After an additional 2 days of empiric dosage adjustment by the attending physician, 86% of the subjects demonstrated a stable INR. Five patients (7%) experienced an INR ≥4. These patients had a nonsignificant trend toward a lower plasma albumin level compared with other patients (p = 0.057, Student's t-test). The INR-driven dose adjustments on days 3 and 4 of this protocol coped with other variables that have been shown to affect maintenance warfarin dosing. These included weight, gender, pharmacologic factors affecting clearance, and the presence of certain predesignated risk factors. CONCLUSIONS: The age-adjusted dosing protocol rapidly achieved a stable INR with minimal overanticoagulation. Patients with low serum albumin levels (<3.0 g/dL) may be sensitive to the effects of warfarin during the loading phase.


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