A 24-year-old man presents in septic shock from an empyema. He is febrile to 103degF, tachycardic in the 120s, and hypotensive to the 90s. His oxygen saturation is 98% on 2-L oxygen. His white blood cell count is 25,000/mL and creatinine is 0.8 mg/dL. His blood pressure does not respond to fluid administration despite a CVP of 15. Which of the following therapies is indicated in managing this patient?