The 23-year-old patient is brought to the emergency department after contacting emergency services to report profound weakness that started in his feet and worsened and spread cranially over the past few days. He reports severe diarrhea after a camping trip a week ago. Upon assessment, strength, sensation, and deep tendon reflexes are significantly reduced, with the lower extremities more severely affected than his upper extremities. There is increased protein in the cerebrospinal fluid found after a lumbar puncture. The patient begins taking more shallow breaths and becomes confused. The patient is intubated and mechanically ventilated. Once the patient is stable, the nurse anticipates administering which medication?