The reason why RNs can't push Propofol is because Propofol is a potent sedative hypnotic agent that is very capable of producing rapid and deep sedation as well as general anesthesia.
Propofol also carries high risks of severe hypotension and respiratory arrest.
The drug Propofol also has no reversal agent and the administration of Propofol also requires specialized airway management training to "rescue" patients that often falls outside of the scope of practice for non anesthesia trained RNs.
Propofol can very quickly move a patient from moderate sedation to deep sedation, where the patient can no longer maintain their own airway.
And unlike fentanyl also known as naloxone or midazolam also known as flumazenil, there's no drug that can be used to reverse the effects of Propofol if the patient happens to stop breathing.
The drug propofol often also causes rapid hypotension or low blood pressure, which also requires special advanced skills to manage properly.
And many state boards of nursing as well as professional organizations also define the administration of anesthetic agents like propofol as well as etomidate, ketamine etc, as the practice of anesthesia, which is also reserved for Certified Registered Nurse Anesthetists or CRNAs or anesthesiologists.
And while many institutions restrict IV push propofol to anesthesiology, there are exceptions that do exist like in Intensive Care Units or ICU and Emergency Departments where the staff are highly trained in airway management and a physician is immediately available.
Although whether an RN is allowed to push propofol often also depends on the specific state regulations and the specific policies of the hospital.
In some cases, RNs that have specialized, documented training and certification in moderate sedation can administer propofol for short procedures.