TOF Question

Our center does about 650 cardiac surgeries a year. I can't remember the last time I cared for a child with TOF who had a BT shunt. (Years ago in another city, the unit I worked in had two infants with BT shunts who died because they were handventilated with 100% O2... very ugly situations.) Most of our kiddies will have an RV-to-PA conduit instead. (I think it's a surgeon preference.) Most of the kiddies we see with TOF have their definitive repair fairly early. Tet spells can be terrifying, and I can certainly understand why the surgeons like to fix them early.

Modified BT shunts move blood from the subclavian artery to the ipsilateral pulmonary artery. RV to PA conduit is a similar shunt but moves blood directly from the right ventricle to the pulmonary artery. Oxygen is a potent vasodilator. When you have a nonphysiologic circulation such as with a BT shunt or an RV to PA conduit, you don't want to tinker with the hemodyamics too much. Dilating the PAs with 100% O2 will flood the lungs, causing severe symptoms of CHF and the onset of pulmonary hypertension as the pulmonary vasculature tries to control the volume of blood within itself. In inexperienced hands this becomes a vicious circle of overcirculation, vasoconstriction, cyanosis, more handventilation and so on. The first child I remember who died from this was an ex-prem who had not only had a cardiac defect, but NEC and ROP. The hospital I worked at had had a cardiac surgery program but it had closed 5 years previously and all cardiac surgical patients were sent to another facility. The baby had gone to the OR for what was expected to be routine closure of colostomy. Either the anaesthetist forgot about the BT shunt or forgot the significance of it. We were told the kiddie was almost ready to come out to us, when suddenly the anaesthetist came running into the unit calling for an epi infusion NOW! The child had begun the swift descent to arrest and they ended up opening his chest to do internal compressions. He came to the unit four hours later than originally expected, with an open sternum, to await transfer to the cardiac center. He died en route. The autopsy findings, coupled with a chart review, pointed solidly at ventilation with 100% oxygen as the proximal cause of death. I make it a practice to check that my JR bag is on a blender whenever I have responsibility for a kiddie with a cyanotic defect, even though in the unit where I work now the RTs are totally responsible for ventilation including the set-up and monitoring. I don't want anything to do with starting that cascade of events that would lead to tragedy.

How very tragic. Thank you for sharing out of your vast wealth of experience. I will share these concepts with my students; hopefully in sharing, tragedies like these can be prevented.

That would be the best outcome in a situation like this, I think. I for one would prefer to learn from someone else's mistakes... not that I would ever hope that a coworker of mine would cause a child's death. You know what I mean. Good luck with your students. If you need any more "help" let me know...