As computer systems grow in size and complexity, their integration, while a necessity, becomes more difficult. Service oriented architectures and middleware systems in general deal with the issue by decoupling the components. However, these architectures are still designed and enacted from a centralised perspective: a single process invokes remote services, unaware of being part of a larger, more complex workflow. We claim that the orchestration-based approach does not scale well with increasing complexity and heterogeneity of the components, such as those required in the enactment of medical guidelines and workflows. Medical guidelines encode different aspects of a medical procedures, and they specify different level of abstraction in the procedure. They have to be adapted to the realities of different clinics and hospitals, to advances in knowledge, and to the changing of available resources within an institution. We address the problem of representing and enacting medical guidelines using a fully distributed approach. The framework provided by OpenKnowledge, based on sharing choreographies among actors, allows the representation and enactment of the coordination aspect of guidelines and the discovery of the medical knowledge provided by the distributed actors.