Use of Synofast® in routine rheumatology practice: diagnostic performance and impact on management of an acute arthritis
摘要
Septic arthritis (SA) is a rare but serious disease. There is no reliable marker for rapid diagnosis. Synofast® is a new device that analyses synovial fluid and can accurately rule out SA within 15 minutes.
ObjectiveTo evaluate the diagnostic performance of Synofast® in routine practice in patients with suspected SA and to assess its impact on patient care.
MethodThis was a monocentric prospective study of patients with acute arthritis of possible septic origin. In addition to the usual blood and synovial bacteriological tests, a drop of synovial fluid was taken for the Synofast® test, which provides three SA risk probabilities: “low”, “possible” or “high”. The physician recorded the management he would have given before the test and the management he actually gave after the test, knowing the diagnostic performance reported in previous studies.
ResultsOver one year, 43 patients were included, of whom eight had SA (18.6%). Sensitivity, negative predictive value (PV) and negative likelihood ratio (LR) were respectively of 75%, 93% and 0.32 when analysing for “high” and “possible” septic risk while specificity, positive PV and positive LR were respectively of 94%, 67% and 8.75 when analysing for “high” septic risk only. The test helps to avoid hospitalisations in 1/29 patients and to defer antibiotic in 1/7 patients. Follow-up and drug management remained unchanged in 95% and 89% of patients, respectively.
ConclusionSynofast® seems to be a valuable tool for the exclusion of SA. The results need to be confirmed in a larger population, especially the impact on management.