Based off of previous experience with Colonel O'Neill, she knows there is little she can do but monitor his vitals and provide him with a high dosage of fluids and vitamins...waiting for the eventual outcome.
Stevenson does eventually die, but his physiology is just beyond that of normal Humans, on the very edge of the Repository's operational range, and his condition barely stabilizes as his dead body begins to lose its core energy.
Once past the precipice, the programming is able to reactivate his overloaded mind and restart his biological functions before it is too late. To Dr. Lam's surprise, her deceased patient comes back to life!
Afterward, she oversees to his needs in the infirmary as he gradually grows stronger, all the while studying him and learning what she can on behalf of the SGC, medical science in general, and her own curiosity.