@RafaistheKingofClay
There isn't a differential diagnosis.
I guess with NEC, we look for distended abdomen, prominent veins, discolouration but it's a dusky colour on the abdomen. And more often than not comes with lead up symptoms such as temp instability, increase in FiO2. Baby would be pale/mottled
Same with sepsis, and we are very hot on septic screens in nicu. A slight change in temp/ HR we screen and start antibiotics
If a baby slips or dislodges their breathing tube no nicu nurse on the planet would wait for them to self correct. I think she's done herself there too. They have a breathing tube for a reason, because they can't self correct. So you take the tube out. You neopuff and maybe they'll either be stepped down to non invasive or a new tube would like to be inserted. Baby's on nicu are rarely completely sedated when intubated. Only in the severely sick generally they will have morphine running via infusion but as little as 8mcgs an hour. So it's possible for these babies to set extubated but we would never leave them self correct.