title: Proper coding of the Abbreviated Injury Scale: can clinical parameters help as surrogates in estimating blood loss?
abstract: OBJECTIVE
  The Abbreviated Injury Scale (AIS) requires the estimation of the lost blood volume for some severity assignments. This study aimed to develop a rule of thumb for facilitating AIS coding by using objective clinical parameters as surrogate markers of blood loss.
  
  
  METHODS
  Using the example of pelvic ring fractures, a retrospective analysis of TraumaRegister DGU(®) data from 2002 to 2011 was performed. As potential surrogate markers of blood loss, we recorded the hemoglobin (Hb) level, systolic blood pressure (SBP), base excess (BE), Quick's value, units of packed red blood cells (PRBCs) transfused before intensive care unit (ICU) admission, and mortality within 24 h.
  
  
  RESULTS
  We identified 11,574 patients with pelvic ring fractures (Tile/OTA classification: 39 % type A, 40 % type B, 21 % type C). Type C fractures were 73.1 % AISpelvis 4 and 26.9 % AISpelvis 5. Type B fractures were 47 % AISpelvis 3, 47 % AISpelvis 4, and 6 % AISpelvis 5. In type C fractures, cut-off values of <7 g/dL Hb, <90 mmHg SBP, <-9 mmol/L BE, <35 % Quick's value, >15 units PRBCs, and death within 24 h had a positive predictive value of 47 % and a sensitivity of 62 % for AISpelvis 5. In type B fractures, these cut-off values had poor sensitivity (48 %) and positive predictive value (11 %) for AISpelvis 5.
  
  
  CONCLUSIONS
  We failed to develop a rule of thumb for facilitating a proper future AIS coding using the example of pelvic ring fractures. The estimation of blood loss for severity assignment still remains a noteworthy weakness in the AIS coding of traumatic injuries.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. Mac.Burkhardt@t-online.de.
authors.forename: M
authors.initials: M
authors.lastname: Burkhardt
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. joerg.holstein@uks.eu.
authors.forename: J H
authors.initials: JH
authors.lastname: Holstein
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. philipp.moersdorf@uks.eu.
authors.forename: P
authors.initials: P
authors.lastname: Moersdorf
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. alexander.kristen@icloud.com.
authors.forename: A
authors.initials: A
authors.lastname: Kristen
authors.affiliation: Institute for Research in Operative Medicine (IFOM), Faculty of Health, University of Witten/Herdecke, Cologne Merheim Medical Centre, Ostmerheimer Straße 200, 51109, Cologne, Germany. Rolf.Lefering@uni-wh.de.
authors.forename: R
authors.initials: R
authors.lastname: Lefering
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. tim.pohlemann@uks.eu.
authors.forename: T
authors.initials: T
authors.lastname: Pohlemann
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Kirrbergerstraße 100, 66421, Homburg, Germany. antonius.pizanis@uks.eu.
authors.forename: A
authors.initials: A
authors.lastname: Pizanis
keywords: Abbreviated Injury Scale (AIS); Coding; Estimated blood loss; Pelvic ring fracture; Rule of thumb
references.citation: Arch Surg. 2003 May;138(5):504-8; discussion 508-9
references.pmid: 12742953
references.citation: J Trauma. 2006 Jun;60(6):1228-36; discussion 1236-7
references.pmid: 16766965
references.citation: Clin Orthop Relat Res. 2012 Aug;470(8):2090-7
references.pmid: 22354608
references.citation: J Am Acad Orthop Surg. 1996 May;4(3):143-151
references.pmid: 10795049
references.citation: J Trauma. 2006 Dec;61(6):1400-7
references.pmid: 17159683
references.citation: Unfallchirurg. 1996 Oct;99(10):734-43
references.pmid: 9005561
references.citation: Injury. 2011 Oct;42(10):997-1002
references.pmid: 21513936
references.citation: Vox Sang. 2011 Feb;100(2):231-8
references.pmid: 20735809
references.citation: Acad Emerg Med. 2011 Jun;18(6):637-43
references.pmid: 21676063
references.citation: Crit Care. 2012 Aug 22;16(4):R163
references.pmid: 22913820