Good news already this morning. I arrived in the ICU to find the respiratory therapist "power weaning" Levi off the nitric oxide, which was treating his pulmonary hypertension. In 45 minutes they had dropped him from 20 ppm to 4 ppm. They have also further dropped his oxygen to 30 percent coming through the ventilator, the level at which they typically extubate patients (we breathe 21 percent oxygen). His oxygen saturation levels remain at 100 percent.
Don't know what might change after surgery, but to us this is a promising sign.