Oksana Grigorieva 911 "He's Losing Blood Badly!"

8/23/2011 10:13 AM PDT

Oksana Grigorieva 911 Call -- "He's Losing Blood Badly!"

TMZ has obtained the 911 call made by Oksana Grigorieva -- moments after her teenage son put his hand through a stained glass window in July, slashing his arm wide open.

Oksana screams frantically into the phone, "A huge chunk of meat is missing out of his arm!" 14-year-old Sasha faints in the middle of the phone call.

According to reports, Sasha -- Oksana's son with actor Timothy Dalton -- was treated at a local hospital and released soon after his bloody accident ... but not without several stitches.