Hello. Well its very difficult to quantitate the pain that someone is to feel during a procedure but I can break it down to the way it will be handled. As you already know the you will receive a local injection at the site of the procedure so you will feel at least a needle before you get numb. Things like technique and size of the needle can help reduce the first stinging sensation. If allowed to settle in and if the depth is correct, there should not be unbearable pain afterwards. All you might feel tugging sensation at the sight of the procedure. The pleura that lines the inside of the chest (AKA parietal pleura) is a sensitive lining and does transmit pain. So deeper injections tend to reduce the sensations of the lining. I have heard my patients complain of a second pricking sensation once the needle for pleurocenthesis is inserted but never has the pain been more than a quick prick. Once the needle is in and the movement stops and the effusion starts flowing out, all you need to do is just stay still and relax and breath normally. For the pain after the procedure, well again it depends on the size of the needle used for the procedure, redness at the insertion site and adequate analgesics for pain control. Local wears off pretty quickle by 20 minutes or so. Therefore taking your first pain killer while in the hospital is recommended. I have had patients who did not even take their pain medications after the procedures while some call back for a stronger pain killer. Most of my patients fare well with a simple paracetamol, some need non steroidals. Very rarely have I prescribed anything stronger. I am sure you must be in good hands and I have no reason to believe that you will have a painful procedure. All should be well by tomorrow. Therefore I wish you a good health