My current job says we have to have LR as a main line. They use anesthesia tubing, connected directly to IV site hanging by gravity and clamped off. Then hang another LR infusing on pump at 75 ml/hr and magnesium on second chamber infusing at 50 ml/hr. Per management, this is awhonn standard to have a mainline of LR. I've never worked anywhere else that we had to have a bag of LR connected to infuse by gravity but clamped off. Is this really an awhonn standard? I've always just considered my LR infusing on a pump to be my primary line. Is mainline and primary line two different things? How do you hang magnesium at your hospital?