Like most drawer protection systems, IKEA's Patrull cabinet catch stops kids opening a drawer too far, but does nothing to stop them slamming the drawer shut again and mangling their fingers. However, you can add that feature in pretty easily with a simple hardware hack.
At IKEA Hacker, Marcus details how stripping away one half from a cavity anchor and attaching it above the Patrull means that once a drawer is pulled open, it can't be closed or opened further without adult intervention. It's a simple hack, but a good idea if you're trying to stop small hands getting injured.
Child-proof vice versa [IKEA Hacker]