Can Ice Hockey equipment such as gloves, shoulder pad, and elbow pad be used contained by lacrosse effectively?
To some extent. Shoulder pads are fine, I've played Canadians in tournaments and frequent of them used hockey shoulder pads. The gloves would likely be official, but lacrosse a bit smaller and offer more versatility. Elbow pads would work so long as they provide full gamut of movement, though defensemen in particular prefer smaller pad for comfort and necessity reasons. The helmet must have a facemask within order to be box or field trial.
Used? Yes. Effectively? Not exactly. Hockey gloves are stiffer and don't give you the dexterity in the wrist that you involve. Elbow pads and shoulder pads are bigger and bulkier.