Dilute Russel Viper Venom Time analysis in a Haematology Laboratory: An audit.

INTRODUCTION: To determine whether the current set of evaluation criteria used for dilute Russel Viper Venom Time (dRVVT) investigations in the routine laboratory meet expectation and identify possible shortcomings. METHODS: All dRVVT assays requested from January 2015 to December 2015 were appraised in this cross-sectional study. The raw data panels were compared with the new reference interval, established in 2016, to determine the sequence of assays that should have been performed. The interpretive comments were audited, and false-negative reports identified. Interpretive comments according to three interpretation guidelines were compared. The reagent cost per assay was determined, and reagent cost wastage, due to redundant tests, was calculated. RESULTS: Only ~9% of dRVVT results authorized during 2015 had an interpretive comment included in the report. ~15% of these results were false-negative interpretations. There is a significant statistical difference in interpretive comments between the three interpretation methods. Redundant mixing tests resulted in R 7477.91 (~11%) reagent cost wastage in 2015. CONCLUSIONS: We managed to demonstrate very evident deficiencies in our own practice and managed to establish a standardized workflow that will potentially render our service more efficient and cost effective, aiding clinicians in making improved treatment decisions and diagnoses. Furthermore, it is essential that standard operating procedures be kept up to date and executed by all staff in the laboratory.

Routine preoperative blood testing in pediatric neurosurgery.

OBJECT: The frequency with which routine preoperative blood test results predict perioperative or postoperative complications is insignificant. The unnecessary ordering of routine tests increases the financial costs and patients' distress. The authors evaluated the effects of routine preoperative testing on patient management and the overall financial costs. METHODS: The authors retrospectively reviewed the medical records and laboratory data for 355 children admitted to the neurosurgical department for elective procedures over a 5-year period (January 2008-December 2012). They excluded all patients admitted for imaging or surgical procedures requiring local anesthesia, and they recorded the results of preoperative and previous (up to 6 months before surgery) blood tests and any abnormalities noted. RESULTS: As a result of the 3489 blood tests ordered preoperatively for 328 (94.6%) of the 355 patients, 29 abnormalities (9%) were detected. Most of these abnormal values were near the reference range, and none significantly affected the progression of scheduled procedures. For only 1 patient (0.28%) was the procedure cancelled because of an abnormality (preoperative partial thromboplastin time), which further testing showed to be a false-positive result. The cost of these tests over 5 years was 5205-10,410 euros ($6766-$13,533 US). CONCLUSIONS: Preoperative tests should be selectively requested on the basis of clinical indication.

Comparison of Russell viper venom-based and activated partial thromboplastin time-based screening assays for resistance to activated protein C.

Thrombotic disease is a significant cause of mortality and morbidity, with an estimated lifetime risk of greater than 10% in Western populations. One of the most common hereditary thrombophilias is the factor V Leiden mutation, which is identified with a screening assay for activated protein C (APC) resistance and confirmed by DNA analysis. In this study, we compared the commercially available Pefakit (Pentapharm, Basel, Switzerland) and Cryocheck (Precision BioLogic, Dartmouth, Canada) assays, 2 recently developed Russell viper venom (RVV)-based screening tests, with the activated partial thromboplastin time (aPTT)-based screening test currently used in our hospital's clinical laboratory. We found that the aPTT-based assay for resistance to APC had a sensitivity of 100%, a specificity of 70%, and a positive predictive value (PPV) of 70%, whereas both of the RVV-based assays exhibited high sensitivity, specificity, and PPV at 100%. In addition, we found that these new functional assays are more cost-effective relative to the screening algorithm previously used in our clinical laboratory and could potentially eliminate the need for DNA analysis, although further study is required.

Feasibility, cost-effectiveness and patients' acceptance of point-of-care INR testing in a hospital-based anticoagulation clinic.

Point-of-care (POC) coagulometers are increasingly used by patients for self-monitoring of oral vitamin K antagonists therapy. We studied the feasibility of introducing POC international normalised ratio (INR) testing in place of standard laboratory assays in a hospital-based anticoagulation clinic with 250 active patients. The CoaguChek XS system was first validated in 253 INR samples and found to have a correlation of r = 0.945 with standard assays. Variations increased with INR readings above 3.5 and this was chosen as the cutoff for acceptance of POC INR results. POC testing was done for 1,332 clinic visits during the subsequent 6-month study. Rate of rejections of INR over 3.5 was 4.3% (95% CI 3.3-5.5%). POC testing reduced clinic visit duration by 35 min (p < 0.001, 95% CI 25-45) without cost increments to patients or the laboratory. Among 232 respondents surveyed, 87.5% (95% CI 82.5-91.5%) preferred POC INR monitoring. Rates of thrombosis and major bleeding complications were 1.2% (95% CI 0.2-3.5%) and 0.4% (95% CI 0.01-2.2%), respectively. In conclusion, provided mechanisms are in place to address increased variations of INR at higher ranges, POC testing can be successfully implemented in busy hospital-based anticoagulation clinics.

MCOs following innovative CMS remote monitoring initiative: self-testing service is designed to lower costs and improve outcomes for anticoagulation therapy.

Managing anticoagulation therapy has been difficult and costly for providers and for payers, as complications are common. For example, the cost of mitigating a single anticoagulation related hemorrhagic complication can exceed $10,000 per claim. In 2002, CMS initiated a new model of anticoagulation patient management that combines technology with remote monitoring to improve traditional care. Managed care organizations are now adopting this model, and improved outcomes at lower cost should result.

Clinically applicable laboratory end-points for treating snakebite coagulopathy.

AIMS: To determine which coagulation tests best reflect the return of clotting function after snakebite venom induced consumptive coagulopathy (VICC). METHODS: Cases of snake envenoming were prospectively recruited to the Australian Snakebite Project (ASP). This study examined cases with VICC treated with antivenom and monitored with serial measures of clottable fibrinogen, prothrombin time (PT) and activated partial thromboplastin time (aPTT). The main outcome measures were times from antivenom treatment until a moderate recovery in the PT (<24 seconds), a measurable aPTT and detectable fibrinogen. RESULTS: Forty-six cases were examined, including 27 brown snakes with proven complete venom neutralisation by antivenom in 25, 16 tiger snake group and three taipans. The times from initial antivenom dose to recovery were: PT<24 seconds, median 9.2 hours (IQR 6.2-11.3 hours); measurable aPTT, median 5.2 hours (IQR 3.4-8.8 hours); and detectable fibrinogen, median 8.8 hours (IQR 5.4-11.7 hours). In 10 cases where fibrinogen was detectable earlier than recovery of the PT, the mean fibrinogen was 0.25 g/L (SD 0.10) compared with 0.6 g/L (SD 0.28) in the remaining 36 cases (p<0.0001), reflecting differing sensitivities between laboratories. In only three patients (7%) was fibrinogen measurable before the other two outcomes, using highly sensitive fibrinogen assays. CONCLUSION: The combination of the PT and aPTT is an effective, clinically available and cost-effective end-point for treating VICC, and may take longer to return to normal after venom neutralisation than previously believed. The fibrinogen assays that are generally in use do not provide any additional useful information.

Overuse of prothrombin and partial thromboplastin coagulation tests in medical inpatients.

INTRODUCTION: In the monitoring of anticoagulant therapy, prothrombin time (PT) is used to measure the effect of warfarin, whereas the partial thromboplastin time (PTT) measures the therapeutic effect of unfractionated heparin. Low molecular weight heparin (LMWH) does not require routine monitoring. OBJECTIVE: We collected data on the frequency of simultaneous PT and PTT requests, where only one or neither is indicated, and estimated the potential cost savings if ordering was appropriate. METHODS: The study was performed at Nassau University Medical Center, a major teaching institution in East Meadow, New York. Inpatient charts were reviewed consecutively until 50 patients prescribed warfarin alone, intravenous heparin alone, or LMWH alone were selected. We then determined which coagulation tests were performed each day for these patients by review of their computerized laboratory results. The costs of laboratory tests were obtained from the hospital laboratory and were used to calculate potential savings. RESULTS: PT and PTT coagulation tests were requested together in all 50 patients. Seventeen patients on LMWH alone had 30 sets of PT/PTT performed (60 tests). Seventeen patients on intravenous heparin had 87 PTs performed. Twelve patients on warfarin had 60 PTTs performed. In total, 232 unneeded PT or PTTs were ordered in these 50 patients, or 4.6 per patient during hospitalization. CONCLUSION: The review of the records of 50 medical inpatients found that PT and PTT were invariably requested together, despite a lack of indication. The 50 patients incurred a total of $2434 in unneeded costs. If representative of common clinical practice, significant cost savings may be possible. Education, computerization, and information on costs of individual tests may reduce unneeded investigations.

Devices for ambulatory and home monitoring of blood pressure, lipids, coagulation, and weight management, part 2.

PURPOSE: The equipment and methods used for ambulatory and home monitoring of blood pressure, lipids, coagulation, and weight management are discussed. SUMMARY: Over 100 million people in the United States have one or more chronic diseases, such as diabetes, hypertension, and asthma. With the goal to improve health while reducing costs and the overall health care burden, ambulatory and home monitoring by pharmacists and patients are receiving more attention. Ambulatory and home monitoring of blood pressure, cholesterol, coagulation, and weight management (including devices for assessing overweight and obese patients, heart rate monitors, and pedometers) are convenient for clinicians and patients. Such monitoring provides pharmacists with an opportunity to differentiate their practices. Studies suggest that patients who are involved in ambulatory and home monitoring take a more active role in their health and may have better adherence to a prescribed diet and medication regimens. Studies also show that ambulatory and home monitoring, if done correctly, provide clinicians with a large quantity of reliable readings for future therapeutic decisions. Devices are also a means for pharmacists to increase their provision of pharmacy services. Ambulatory monitoring is billable in many clinic settings, and the devices can be a profitable addition to prescription services. CONCLUSION: Many devices are available to assist patients and clinicians in monitoring blood pressure, lipids, coagulation, and weight management. Familiarity with the devices will help in their proper selection and use.

Will direct thrombin inhibitors replace warfarin for preventing embolic events in atrial fibrillation?

PURPOSE OF REVIEW: Atrial fibrillation is the most frequently encountered tachyarrhythmia requiring therapy. Treatment issues include therapy for any reversible cause; the identification and treatment of any underlying structural disorder; control of the ventricular rate, both for symptom reduction and prevention of tachycardic-induced cardiomyopathy; restoration and maintenance of sinus rhythm when symptoms persist despite rhythm control; and anticoagulation in patients with high-risk markers for systemic embolization: age over 65 years, hypertension, diabetes, ventricular failure, rheumatic valvular disease, and prior stroke or other embolic event. In such patients, anticoagulation with warfarin is currently recommended. Warfarin therapy carries significant risks (especially bleeding), inconveniences (the cost of prothrombin time monitoring, the need for rigid dietary stability, the concerns of drug and herbal interactions), and other concerns (the issue of generic formulation substitution). RECENT FINDINGS: Under development are oral thrombin inhibitors. The first to reach clinical approval will likely be ximelagatran. In clinical trials to date, ximelagatran has proven to be equal to or superior to warfarin in the prevention and treatment of thrombophlebitis. In atrial fibrillation patients, the Stroke Prevention Using Oral Thrombin Inhibitor in Atrial Fibrillation (SPORTIF) trials completed so far appear to show a similar or better efficacy for ximelagatran versus warfarin as regards both prevention of embolic events and lower risks of major bleeding, with no serious adverse effects except for apparently reversible alterations in liver function tests in approximately 6% of subjects, all occurring early in therapy to date. If the remaining SPORTIF trial (SPORTIF V) is confirmatory (results to be available in late 2003), it is expected that this exciting new product will be submitted this winter to the Food and Drug Administration for approval. Recent findings also include the observations in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) and Rate Control Versus Electrical Cardioversion (RACE) trials that anticoagulation should not be discontinued despite the restoration and maintenance of sinus rhythm. SUMMARY: Oral direct thrombin inhibitors, such as ximelagatran, appear likely to replace the use of warfarin in most patients in the near future, because of a better risk-benefit profile.

Cost effectiveness of monitoring warfarin therapy using standard versus capillary prothrombin times.

The authors assessed the cost effectiveness of monitoring warfarin therapy guided by standard plasma prothrombin times performed on blood samples obtained by venipuncture versus prothrombin times performed on capillary whole blood samples obtained by fingerstick. Twenty patients receiving long-term oral anticoagulation had either standard or capillary prothrombin times determined every other week for eight weeks in a cross-over design. All time intervals were monitored, including receptionist, secretarial, nursing, phlebotomy, etc., and costs for all materials, procedures, and labor were calculated. The total cost per test by the capillary whole blood prothrombin time method was significantly less than by standard prothrombin time methods ($7.55 vs. $15.64) even though the nurse-patient encounter time was greater per test for the capillary method (12.4 minutes vs. 8.3 minutes). The management of oral anticoagulation guided by prothrombin times performed on instrumentation designed to sample capillary whole blood should result in a significant cost savings, and because of the immediate availability of results, provide the potential for improved health care.