CCU staffing ratio criteria or guidelines for acuity

Hello. I am an RN in a coronary care unit in Canada. Our hospital is a regional cardiac center and our unit is 8 beds. Patient acuity ranges - we can have cardiac arrests, hypothermia patients, ST elevation myocardial infarctions, intubated patients, patients with intraortic baloon pumps, etc.

We are currently having issues with our management with respect to adequate staffing for acuity and what criteria / guidelines are appropriate for doubling patients for one staff nurse (i.e. what is the acceptable acuity of two critical care patients to be suitable for one nurse).

I welcome any input as to what other nurses out there are doing and what tools / criteria / guidelines are used in your own critical areas to determine staffing ratio.

Regards