Why are they giving tripp halstead baclofen instead of a pain killer like oxycodone or hydrocodone? why did they install a pump instead of oral meds?

Beats me: You need to be asking these questions to whoever "they" are who are giving it to whoever they are giving it to, for whatever condition. It is not possible without knowing the underlying issues involved in this illness or injury. Baclofen is a strong muscle relaxant, and if the pain involved is related to muscle spasm would be a reason to give it. Why in a pump? I have no idea. Ask your doctor!

Baclofen: Baclofen can be used for muscle spasms. Sometimes an intrathecal pump is used with opioids as well for uncontrolled pain when someone is not responding to oral pain meds. Intrathecal pump is last resort for controlling pain and there can be a lot of problems from them including infection. I don't know the specifics of what kind of pump they placed in tripp but i hope he is doing better.