As they move to exchange patient information with hospitals and other health care partners, doctors are suffering sticker shock: The vendors of the health care software want thousands of dollars to unlock the data so they can be shared. It may take an act of Congress to provide relief. The fees are thwarting the goals of the $30 billion federal push to get doctors and hospitals to digitize health records. The exorbitant prices to transmit and receive data, providers and IT specialists say, can amount to billions a year. And the electronic health record industry is increasingly reliant on this revenue.