I have a question and would like some insight with regard to triage and how your facility uses the 5 level triage model in order to place patients waiting in the Emergency Room.

I work in a busy ER and have been filling in as a charge nurse when our regular ones are out for vacation or illness. I have noticed a very large gap in people's definitions of what nurses consider specifically level 2-4 triage patients.
Our policy at the facility is unfortunately very vague and leaves a lot to interpretation by each person and the online resources I've found break the triage into two obvious models.

One specifically delineates patients based on their medical appearance and response to questions presented by the triage nurse, and then bases their triage level on how long they can wait to see a physician.
Level 1: they need to see a physician immediately (active seizure, cardiac arrest, etc)
Level 2: they can wait 15 minutes to see a physician
Level 3: they can wait up to 30 minutes to see a physician
Level 4: they can safely wait up to one hour
Level 5: they can safely wait up to four hours

The second model I've seen starts out much the same way:
Level 1: they need immediate life saving intervention
Level 2: they are in distress and their vital signs indicate that a rapid decline may be imminent if they aren't treated expeditiously
Then, this model changes to triage based on the resources that may be needed while in the department:
Level 3: they may require several resources in the department in order to properly diagnose and treat their complaint/illness (abdominal pain requiring lab, xray or ultrasound)
Level 4: they may require one resource to properly diagnose (an xray or only lab work)
Level 5: they should not require any resources in the department other than evaluation and treatment by a physician (prescription refill, referral to outsourced care like a dentist)

It seems like nurses in our department are using pieces from each triage model and using them to make judgements about their own triage. We have several nurses who work at different facilities and some who have brought different experiences with them, and being a charge nurse makes it difficult to decide if patients are being 'over' or 'under' triaged.

An example: a patient had lab work done at his physicians office. The results arrived to the physician and they called the patient at home and told them to go to the ER because his potassium was 6. There was no indication in triage that he would have any reason for an elevated potassium, his vital signs were normal, and his EKG was read as Normal Sinus Rhythm.
Personally, I would consider this patient a 4. He needs to have his lab work repeated (an elevated potassium is a common finding on a hemolyzed specimen), but is otherwise in no distress with a normal EKG and normal vital signs. The triage nurse on duty at the time made him a 2.

Another example: a patient comes in by rescue as a restrained passenger in a motor vehicle accident. The collision was on the driver's side and the patient is complaining of shoulder and head pain. He denied loss of consciousness and was awake, alert, oriented x 4, remembered the collision and denies any changes in vision. His vital signs are stable. A nurse filling in from a trauma hospital nearby made him a 4 after triage. Another nurse argues with him about his triage level, indicating that the physician would order an xray and probably a CT head, so that would make him a 3.

I understand the second nurse is using the second model and was triaging based on the resources, but my question is... has anyone experienced the same sort of disparity in their practice with regard to triage, and what solutions or recommendations have you used in order to increase consistency in your hospital's triage practices?