Yup, that's her!

Britney Spears was rushed to the emergency room on Thursday night after a stand-off with police.

Cops were called to the trainwreck's house after she refused to hand over custody of her kids to Kevin Federline's bodyguard.

The showdown lasted almost FOUR hours and K-Fed showed up, as did his lawyer and a representative for Spears law firm, you know, the ones that want to quit.

Police have said that Spears was discovered to be under the influence of an unknown substance.

Thankfully the children are back with K-Fed now and Spears will be held for psychiatric evaluation at the hospital.

Hopefully the court will order Britney to undergo 30 days - or more - of mental evaluation.

Update: Spears was taken to Cedars Medical Center, we're hearing.