Algorithms for monitoring warfarin use: Results from Delphi Method

Abstract

Warfarin stands as the most prescribed oral anticoagulant. New oral anticoagulants have been approved recently; however, their use is limited and the reversibility techniques of the anticoagulation effect are little known. Thus, our study's purpose was to develop algorithms for therapeutic monitoring of patients taking warfarin based on the opinion of physicians who prescribe this medicine in their clinical practice. The development of the algorithm was performed in two stages, namely: (i) literature review and (ii) algorithm evaluation by physicians using a Delphi Method. Based on the articles analyzed, two algorithms were developed: "Recommendations for the use of warfarin in anticoagulation therapy" and "Recommendations for the use of warfarin in anticoagulation therapy: dose adjustment and bleeding control." Later, these algorithms were analyzed by 19 medical doctors that responded to the invitation and agreed to participate in the study. Of these, 16 responded to the first round, 11 to the second and eight to the third round. A 70% consensus or higher was reached for most issues and at least 50% for six questions. We were able to develop algorithms to monitor the use of warfarin by physicians using a Delphi Method. The proposed method is inexpensive and involves the participation of specialists, and it has proved adequate for the intended purpose. Further studies are needed to validate these algorithms, enabling them to be used in clinical practice.

Elaboration and validation of an algorithm for treating peripheral intravenous infiltration and extravasation in children

“…The 22 potential participants were invited via email, e-mail messages, obtaining consent from 14 participants and, of these, 13 remained until the third assessment. According to studies of algorithm validation, the number of participants varies between 19 and 38 ( 15 - 16 , 19 - 20 ). However, it is verified in the literature that there is no consensus regarding the number of participants to make up the panel of experts ( 21 ) .…”

Farmacoterapia da trombose arterial

“…Em estudo realizado por Kano et al (2017), a warfarina passou a ser comercializada no ano de 1954 e até os dias atuais, vem sendo o anticoagulante oral mais prescrito para profilaxia e tratamento da trombose.…”

“…Outros pontos positivos no uso da warfarina para eventos trombóticos é que, apresenta eficácia acima de 90%, é de baixo custo e tem fácil acesso tornando-se importante alternativa terapêutica na prevenção da trombose para todos os níveis populacionais, sobretudo os de baixa renda (Kano et al, 2017).…”

“…Segundo Stergiopoulos e Brown o monitoramento do RNI em conjunto com os protocolos clínicos validados de anticoagulação e a adesão do paciente, surge como uma forma viável no uso da warfarina (Kano et al 2017). Chun et al (2020) através de um estudo relataram que pacientes diagnosticado com síndrome respiratória aguda, COVID-19 estão ligados a complicações tromboembólicas concomitantes e hipercoagoabilidade.…”

“…A farmacoterapia com a warfarina inicia-se com uma dose padrão, sendo ajustada através do RNI do tempo de protombina. Estudos trazem discordância a respeito da dose inicial, a frequência do monitoramento do RNI e o ajuste da dose em evento adverso (Kano et al, 2017).…”