COMA by Michael Crichton

Nancy Greenly is admitted to the Boston Memorial Hospital for a curettage and suddenly lapses into a coma during reanimation. Her best friend Susan Wheeler, an intern at the hospital, wants to find the cause no matter what. During her investigation, a dumbfounded Susan discovers that there are ten similar cases registered in the Boston Memorial Hospital this year. The warden, who knows of Susan’s investigation, puts an end her quest. Concerned about her wellbeing, he asks her to go and pay a visit to the psychiatrist. A few hours later Susan finds out that an American football player, brought in for minor surgery, also lapsed into a coma.