Correlation of the change in the International Normalized Ratio and decreasing the Coumadin dosage following total joint arthroplasty.
This retrospective pilot study determined whether a change in the daily International Normalized Ratio (INR) correlates with a decrease in Coumadin (DuPont Pharma, Wilmington, Del) dosage. Four hundred seventeen patients yielded 1167 pairs of INR values and Coumadin doses. An increase in INR > 0.4 units correlated 81% with a decrease in the Coumadin dose (P < .05). In patients aged > or = 70 years, the correlation fell to 70% compared to an 89% correlation in patients aged < 70 years (P < .05). The correlation fell to 78% in women, while men exhibited an increase to 87% (P < .05). Although this is a pilot study, when managing postoperative Coumadin anticoagulation for orthopedic patients, an increase in INR > 0.4 units correlates highly with the need to decrease the Coumadin dose. A prospective study is needed to test the usefulness of this parameter.
Rosenbaum
Cathy Creger
CC
Bethesda North Hospital Pharmacy, TriHealth, Cincinnati, Ohio 45242, USA.
Woods
Scott E
SE
Hasselfeld
Kimberly A
KA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D019643:Arthroplasty, Replacement; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011183:Postoperative Complications / Q000517:prevention & control*; D011517:Prothrombin Time; D011655:Pulmonary Embolism / Q000517:prevention & control; D012189:Retrospective Studies; D020246:Venous Thrombosis / Q000517:prevention & control; D014859:Warfarin / Q000008:administration & dosage*
D000925:Anticoagulants; D014859:Warfarin