Timing tourniquet-on to first stick and adding a 10-count breath, I saw visible flinches at about 12% this month (29/241) when I stayed under 45 seconds. Do you have a comfort benchmark for 21G vs 23G butterflies on adult ACs, or is the difference negligible?
I’ve found 21G on adult ACs feels the same as 23G if you soften the first tube’s vacuum — feather the holder for a second like easing a clutch — and release the tourniquet at flash. When I’m “under 45 seconds” that keeps flinches under about 10%; have you tried low‑vac tubes or timing a 4–6s exhale during the stick?
Quick warm pack 30–60 seconds cut 23G flinches for me; under 45 seconds, I also anchor skin firmly. @PhlebAna, ever compare with a low-vac pediatric tube first?
On ACs I treat 23G as a fragile-vein only; the dwell is longer and I see more micro-movement flinches, so 21G wins if the vein’s >=3 mm. Lock the wings to the skin with two fingers and rest your knuckle on the arm; that single stabilization step cut my “29/241”-type spikes by about half. Do you see a drop when you brace the hub versus just anchoring the skin?