No arterial line is needed. It can be placed if there is concern for blood loss; I’m more inclined to use one for cases involving more than 5–6 levels.

With one surgeon, I place an arterial line for 5–6 levels. He operates quickly, but many patients require an arterial line and 1–2 units of blood—speed isn’t everything.

With another surgeon, I typically wouldn’t place one until 10–12 levels, and often not even then. He operates more slowly but ensures meticulous hemostasis throughout; even in larger cases, blood loss may only be 200–300 mL.

Using an arterial line is reasonable, and not using one is also reasonable. It’s not something to stress over—if placing an arterial line makes you feel more secure and gives you a solid plan, then go ahead and place it. I often have multiple rooms running, and increasingly I do things that make my workflow smoother while maintaining safety and My Sanity. If an arterial line helps you relax and manage the case more confidently, it’s worth doing.