I had one of those moments recently. I admitted an infant from an outlying hospital who had been seen in the ED for decreased urine output. Further history revealed a several day history of being unwell, a slight cough, some vomiting. The baby was also diaphoretic, small for age, mottled and significantly tachypneic. A chest x-ray revealed massive cardiomegaly so the kiddie was sent to us for assessment and maybe some HFNC. On arrival there was much crying and squirming, as one would expect from someone in the second half of their first year. The cardiology resident was already on the unit waiting for the kid so the echo was started right after we'd moved from the transport stretcher to the crib. About 10 minutes before the eventual end of the echo, the baby fell asleep... and my spidey senses started really tingling. The nap lasted only a few minutes and then the crying started again, but much less vigorously. Then, in the time it took the resident to call his attending, the baby's heart rate dropped from 140 to 120... then 100... then 70 and I was calling for the crash cart. We did CPR on and off for more than an hour with the inevitable cannulation for ECMO. The kiddie's mother and grandmother were in the room for the first part of the resus, and I remember hearing the mom say, "Is my baby dead?" several times. We moved them into the next room and let them watch through the doorway while we carried on with what needed doing. Every so often one of us would go to them and update them on what was happening. Both of them had been up since early the previous morning and were exhausted, but they stayed put. By 4 am things had settled down and I was able to really explain what had happened and what would likely happen next.
This baby had a witnessed arrest and got good CPR. It's nothing short of a miracle that the outcome was virtually a complete recovery. The underlying extremely rare cardiac defect was repaired and after a few days of ongoing support, decannulation and extubation followed with the kiddie back to baseline neurologically. Sometimes we win one!