The good news is that Chicago Med has survived and even thrived after losing longtime regulars, as proven by the departure of Colin Donnell’s Connor, Norma Kuhling due to Ava’s bloody ending, and Rachel DiPillo’s Sarah.
Med will have a vacancy for both an ED pediatrician and a nurse, but Natalie definitely isn’t the only ED doctor who treats kids, so her departure doesn’t necessarily mean that Med needs to add another pediatrician character.
As a nurse, April has been able to pitch in on just about every kind of case, so any new nurse wouldn’t necessarily need a specialty.