public ReturnCode AtomicPublish(string userName, string password, string virtualHost, string hostName, string exchangeName, string queueName, string message)
{
    using (IConnection conn = new ConnectionFactory()
    {
        UserName = userName,
        Password = password,
        VirtualHost = virtualHost,
        HostName = hostName
    }.CreateConnection())
    {
        using (IModel model = conn.CreateModel())
        {
            model.ExchangeDeclare(exchangeName, ExchangeType.Fanout, true);
            model.QueueDeclare(queueName, true, false, false, null);
            model.QueueBind(queueName, exchangeName, "", null);
            byte[] messageBodyBytes = System.Text.Encoding.UTF8.GetBytes(message);
            model.BasicPublish(exchangeName, string.Empty, null, messageBodyBytes);
        }
    }
    return ReturnCode.OK;
}

private static IConnection _connection {get;set;}
private static object LockObject = new object();
private static IConnection GetConnection (string username, string password, string virtualHost, string hostName)
    get{
        // do work here in case the connection is closed as well.
        if (_connection == null){
            lock(LockObject){
                if (_connection == null){
                    _connection = new ConnectionFactory
                       {
                           UserName = userName,
                           Password = password,
                           VirtualHost = virtualHost,
                           HostName = hostName

                       }.CreateConnection();
                }
            }

        }
        return _connection;
    }
}

public ReturnCode AtomicPublish(string userName, string password, string virtualHost, string hostName, string exchangeName, string queueName, string message)
{

        using (IModel model = GetConnection(userName, password, virtualHost, hostName).CreateModel()) //lazy loads the get connection
        {
            model.ExchangeDeclare(exchangeName, ExchangeType.Fanout, true);
            model.QueueDeclare(queueName, true, false, false, null);
            model.QueueBind(queueName, exchangeName, "", null);

            byte[] messageBodyBytes = System.Text.Encoding.UTF8.GetBytes(message);
            model.BasicPublish(exchangeName, string.Empty, null, messageBodyBytes);
        }

    return ReturnCode.OK;
}