ROS generation

My first encounter with thermoplasticity in human biology I first became aware of this seeming paradox as a neurosurgical resident in my first year of training. We were doing a real "gnarly" brain surgery case. It was a young mother who had a massive basilar tip aneurysm. Back in the mid 90's before endovascular coiling procedures we use today, this was the most risky operation that existed in all of medicine. I spent a month prepping for this case. We had to enlist the cardiovascular surgeons to come in and surgically open the patients chest wide open to stop her heart on purpose temporarily and place her on complete cardiopulmonary bypass to stop all the blood flow to her brain. We had less than 20 minutes to then place a clip across the aneurysm to save her life. To complete this herculean surgical task, we had to fill her entire chest cavity with ice to preserve her heart muscle and cool her core temperature so that we could have 20 minutes to complete the brain surgery. Simultaneously, we would open her skull and split the Sylvian fissure in the brain and approach her basilar artery in the geographic center of her head and attempt to put a clip on it without disturbing any of her surrounding anatomy. The best mental image I can give you for this is the ultimate game of "Operation" you used to play as a kid. You must avoid hitting the sides or the nose lights up!!!! One problem in this case, in this game there was live bullets. This maneuver was deadly if not performed correctly the first time. This is one of the most delicate surgeries one can do on a human. Moreover, even if we were successful with the clip obliteration of the aneurysm, we had to restart her frozen heart, get her off cardio pulmonary bypass without an air embolus and awake. In this case everything went well until the last part and this taught me a lesson I would never forget. She died after the operation was a complete success. Her head was already closed up surgically and dressed, the intraoperative angiogram looked awesome, and we restarted her heart and got her off cardio pulmonary bypass without any evidence of a stroke and then she died suddenly. She received two units of cooled banked blood because our surgical team felt she lost some ability to carry oxygen in her blood because several of the monitors showed she had a low oxygen carrying capacity of her hemoglobin. This concerned us because we were worried about her risk of having a stroke because of low oxygenation due to her loss of blood flow for 20 minutes when she was on full bypass. So we did what any surgeon would do. We gave her blood to restore her oxygen carrying capacity and the oxygen monitors showed her oxygenation had totally returned to normal. We were all happy until I noticed her pupils were fixed and dilated when I was putting on her dressings. She also had blue fingers. And then all of a sudden she got a fatal heart rhythm, and she died right there in my arms. I was devastated. I will never forget talking to her family later that day.