How to keep dad out of tangled blankets, and thus falling?

If the blankets are tucked solidly on the opposite side of the bed and not tucked in on the exit side, this should help stop him getting tangled.

From what I have seen in facilities is the bedding is to small to deeply tuck under the mattress. You may have to provide full size blankets for him. However, if you aren't local to him, save your money. The bedding will disappear in the laundry.

Two common use items are bed alarms & lowering beds.

Bed alarm: will beep to alert staff - but only once he has moved off the bed.

Lowering bed: if he falls from bed - it's a much shorter fall. (Often onto a 'crash mat' next to the bed).

These strategies are not suitable for everyone in every situation. May even cause MORE falls sometimes - depending on cause of falls.

Neither will prevent him getting tangled in the blankets either. I'm sorry I can't think of anything to prevent that!

Hopefully it was just a 'one off' 🤞

He said so. Of course he often mixes thing up, but he has stuck with this reason.

You could ask about a bed assist rail, it's a short rail positioned by the head of the bed so it doesn't impede getting in and out but provides a support to aid standing and sitting.

https://www.agingcare.com/products/ez-adjustable-bed-rail-136320.htm

https://www.agingcare.com/products/bedcane-136322.htm

Bed rails are not permitted in managed care anyway, so.....
This may be an odd event with dad getting tangled in his blanket, and not something to be concerned with on an ongoing basis, if thats what caused his fall in the first place. How was it determined what caused this fall?

Why do you think that it's tangled blankets that caused the fall?