RT Journal Article SR Electronic T1 The lost sponge: patient safety in the operating room JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1275 OP 1278 DO 10.1503/cmaj.110900 VO 184 IS 11 A1 Amanda Grant-Orser A1 Paul Davies A1 Sukhbir Sony Singh YR 2012 UL http://www.cmaj.ca/content/184/11/1275.abstract