Importance of device evaluation for point-of-care prothrombin time international normalized ratio testing programs.

OBJECTIVE: To determine the accuracy of 2 commercially available point-of-care devices relative to plasma international normalized ratio (INR) values. PATIENTS AND METHODS: Point-of-care INR testing was performed with the CoaguChek and ProTime 3 devices in consecutive patients attending an anticoagulation clinic between June 18, 2003, and August 6, 2003. Results were compared with plasma INRs using a sensitive thromboplastin (International Sensitivity Index, 1.0). RESULTS: Ninety-four patients agreed to participate in the study. Relative to the plasma INR, values were in agreement +/-0.4 INR unit 82% and 39% of the time for the CoaguChek and ProTime 3 devices, respectively. The mean +/- SD CoaguChek INRs were 0.2+/-0.31 unit lower, whereas ProTime 3 INRs were 0.8+/-0.68 unit higher than plasma INR values. Treatment decisions based on these data would have resulted in inappropriate dose adjustments 10% and 22% of the time for these 2 respective devices. Correlation with plasma was greater for the CoaguChek (r2=0.90) compared with the ProTime 3 device (r2=0.73). CONCLUSIONS: Optimal warfarin treatment requires accurate measurement of the INR. The choice of a point-of-care device for INR management depends on the reliability of INR data generated by the device.

Compression therapy for chronic venous insufficiency.

Compression therapy provides a means to treat venous stasis, venous hypertension, and venous edema. Different methods of compression therapy have been described periodically over the last 2,000 years. In addition to static compression, specialized compression pumps have been developed and a technique of massage called manual lymphatic drainage has emerged to treat primary and secondary lymphedema. Objectives of compression therapy are to reduce the swollen limb to minimum size, maintain that size, and allow the patient to participate in the care of his limb whenever possible. Reduction therapy is achieved by limb elevation, compression pumps as necessary, and compression wraps. Maintenance therapy largely consists of compression wraps or compression stockings. Nonelastic devices have found a place in treating severe lymphedema but it should be emphasized that periodic follow-up must be done during maintenance therapy so that adjunctive maintenance measures can be added as needed.

A different way to look at varicose veins.

OBJECTIVE: The development of varicose veins is commonly attributed to vessel wall degeneration. The idea that varicose veins occur because of pathological processes, however, is challenged by certain observations. For example, their high prevalence (50% or greater) in many populations makes it statistically "normal" to have varicose veins; their well-established genetic predisposition raises the possibility that this high prevalence reflects a survival benefit. One way to explain this apparent contradiction is to theorize that varicose veins are produced by the same mechanism(s) that lead to the growth and remodeling of other types of blood vessels. If so, being "good" at forming varicose veins may also predispose to being "good" at forming various types of collateral blood vessels when necessary. METHODS: A selected literature review was conducted. Works chosen for review included those suggesting that: the process of varicose vein formation may share the same basic mechanisms as the formation of collateral veins, arteries, and lymphatic vessels; and clinical outcomes may be different between subjects with and without varicose veins. RESULTS: Evidence suggests that subjects who are "good" at forming varicose veins may also be "good" at forming various types of collateral vessels, and they may have better overall survival (with less cardiovascular morbidity) than those without varicose veins. CONCLUSIONS: Varicose veins may be "the price we pay" for an enhanced ability to form collateral vessels when necessary.