Hello, I am Dr. Aditya Gudhate and try my best to answer your question. Drainage of a lung fluid collection is a relatively safe procedure and only requires local anesthesia. Your father will feel sore for a while but that's it. Some patients may be given sedation if they are too anxious. In any case there is nothing to be worried on that front. I hope you are satisfied with my answer. I hope your father feels better soon!