<s>[INST] Hi yes… i am a retired OB nurse, my girlfriends husband just had knee surgery on a recent total knee… they found a tumor inside the bone…. 1 day post op at home with lower chest pain in ribs area and in his back. He had general anesthesia for 1 and a half hours….. but finding it hard to breathe… i told them to call the Dr. i am concerned about possible blood clot to the lung??? what do you think [/INST] Hello dear, thanks for your question on HCM.Yes, you are right about possibility of blood clots in lung. This is known as Pulmonary Embolism (PE). And he is having following risk factors for PE1. General anesthesia2. Knee surgery3. Bone tumourHis symptoms are also favouring possibility of PE.So better to get done CT pulmonary angiography to rule out PE.Another possibility is fat embolism. As it is also seen after long bone surgery. In this instead of blood clots, fat globules from bone marrow reach the pulmonary artery and cause blockage.So consult pulmonologist and discuss about these possibilities. </s>