Telemedicine systems currently have increased the volume of information stored in their databases. A centralized telemedicine system project covers datasets that ranges from personal patient's information, physicians and institutions to all images of examinations performed. As they store large amounts of examinations, the medical databases can reach several terabytes of volume. This paper presents a contribution characterized by an asynchronous replication model for medical distributed databases. The model, called PostgresReplication, is an extension to the relational database PostgreSQL. In our experiment, an engine has been created to manage all integration operations and information replication for the medical databases. The early results indicate that the model and its implementation have successfully reached a good performance level and interoperability.