Reforge the Severed Meridians

In his previous life, the protagonist was an emergency-room doctor in the modern world. After a misdiagnosis led to a patient's death during resuscitation, he suffered a mental breakdown and unexpectedly transmigrated. What he gained after transmigrating was no golden finger, but a kind of “near-death experience” from the moment before he died in his previous life. Whenever he comes close to death in this world, he briefly returns to the scene of his former patient's death and, from an observer's perspective, reexamines every detail of that failure.