The end credit "In memory of Michael C. Claypool" commemorates the death of the show's set decorator. Claypool died of cancer in March 2000, the second series contributor to die of the disease in the sixth season (the other being Christopher Salamunovich who received a similar credit in 6x01 "Leave It to Weaver").
An intraosseous line is used to inject blood, fluids and medication directly into the bone marrow, where it is then distributed through the venous system. Intraosseous access is typically done in infants when high fluid volume is needed, as their veins are too small; and also in adults when standard intravenous access is not available or possible, such as massive blood loss causing the veins to collapse. Access can be done with either a standard large-bore IV needle inserted into the tibia or a special intraosseous device that is designed to rapidly insert a line into the sternum. Intraosseous access devices have become standard in military medical kits, as they are easy to use and allows anyone with basic first aid training to administer fluids and intravenous drugs, it also has the advantage of allowing combat medics rapid access to the venous system in situations where there isn't time to properly locate a vein, like in the middle of combat.
Addison's disease is a rare long-term endocrine disorder, specifically it is an auto-immune disorder where the immune system attacks a person's own adrenal glands preventing them from producing steroid hormones like cortisol. Symptoms include abdominal pain and gastrointestinal abnormalities, weakness, weight loss and skin darkening; extremely low cortisol levels can cause an adrenal crisis which presents with low blood pressure, vomiting, lower back pain, and loss of consciousness. Treatment involves replacing the absent hormones, people with Addison's have to take corticosteroids for the rest of their lives, the most commonly used steroids are hydrocortisone, prednisone, prednisolone and fludrocortisone.
Morris Chestnut would later play Dr Prentiss in Nurse Jackie
Julianna Margulies (Carol Hathaway) & John Cullum (David Greene) also worked together on episode 4.18, Death of a Client (2013), as Alicia Florrick & Cardinal James respectively.