Debbie Branson appeared cool and calm Monday as she offered a glimpse of the immediate future of Parkland Memorial Hospital. It had been five days since Dallas County's public hospital passed a critical government survey that would assure future federal payments for patient care. Seated in a small office in the hospital's executive suite, Branson acknowledged the intense pressure she felt as chairwoman of Parkland's board of managers the past 18 months. "It's been stressful, very stressful," she said of overseeing a hospitalwide improvement process. It included revamping the Parkland emergency department, hiring more nurses and retraining nearly the entire hospital staff.