Sigma SR, a new method of measuring erythrocyte sedimentation rate. Its value in studying the action and interactions of non-steroidal anti-inflammatory agents

Abstract

Sigma SR is a new method of measuring erythrocyte sedimentation rate (ESR) and is characterized by an unvarying haematocrit, routinely corrected to 35%, and the sum of 4 sedimentation levels at 20, 30, 40, and 50 minutes. Two studies were carried out in patients with inflammatory arthritic disorders; the first in 25 patients treated with 1800 mg ibuprofen daily for 7 days, and the second in 31 patients treated either with indomethacin alone (150 mg/day) or combined with aspirin (1500 mg/day) for 5 days. In addition to the assessment of clinical parameters, the ESR was measured using the classical Westergren and the sigma SR methods. The results showed that there were little or no changes from baseline values in the ESR using the Westergren method. With the sigma SR method, however, statistically significant changes were recorded after treatment and these correlated with the clinical findings which demonstrated the anti-inflammatory action of ibuprofen and the reduction in activity of indomethacin by aspirin.