Federal regulators are giving themselves an extra four months to perform a surprise do-or-die inspection of Parkland Memorial Hospital. Under the original safety oversight agreement with the public hospital, struck in late 2011, Parkland was supposed to undergo such a survey some time before April 30, 2013. It could still happen any day now. But regulators recently realized that not enough time was built into the agreement to allow for the element of surprise, said David Wright, deputy regional administrator for the U.S. Centers for Medicare & Medicaid Services.