Whittington Health has gone live with its Medway patient administration and A&E system from System C, a McKesson company.
The trust was running the legacy Totalcare PAS from McKesson and went live with the Medway PAS at the end of September.
Eleven trusts running Totalcare are due to deploy the Medway PAS before the support contract for the system expires at the end of March 2014.
Whittington is the first of these sites to go-live and looks likely to be closely followed by a further four Totalcare sites over the next two months.
Whittington plans to be one of the first paperless NHS trusts by 2015 by rolling out a full electronic patient record system over the next two years.
It deployed the Medway maternity module in May this year, but waited to go live with the PAS and A&E systems in the second of its three-phase deployment.
The third phase of its deployment will be a GP portal with an integrated community module, due to be implemented in late 2014.
The maternity module is being trialled on iPads and interfaces with child health, radiology and results reporting, as well as the new PAS and A&E systems.
EHI reported last month that a number of Totalcare sites due to go-live with Medway this spring and summer had postponed their deployments.
Nottingham University Hospitals NHS Trust is on track to go-live at the end of this month.
Southend is looking to deploy the system at the end of November, sharing a go-live weekend with Barking, Havering and Redbridge University Hospitals NHS Trust.
Basildon and Thurrock University Hospitals NHS Foundation Trust is also planning a November go-live of Medway.
Colchester was originally due to go-live in April 2013, but pushed this back to mid-October. The trust told EHI it is now unlikely to go-live before April next year.