I've been in ER for the past 4 years and a floor nurse before that. I've come to a point where I wanted a change in my career and decided to pursue OR nursing. Before taking a dive into OR nursing, I recommend doing a shadow/observation shift if you are able to do so - I did this before I made my decision. It will allow you to have a better idea of how the flow of OR works and the different roles the nurse has. I've recently completed my training (additional schooling/certification - depends on the institution if required) and about to start in the OR shortly. As for the hours, it also depends on the institution - at my institution the nurses work 8 hour shifts. Depending on the case, will depend on how long the scrub nurse stands - could be 1-2 hours or even 8+ hours. As for the different roles, at my institution there are only RNs therefore nurses scrub or circulate. I'm still learning the ropes of the OR and excited for this new path in my career. Good luck with your decision!