title: Hyperchloremia is associated with 30-day mortality in major trauma patients: a retrospective observational study.
abstract: BACKGROUND
  Chloride is important for maintaining acid-base balance, muscular activity, osmosis and immunomodulation. In patients with major trauma, chloride levels increase after fluid therapy; this is associated with poor clinical outcomes. The purpose of this study was to determine whether hyperchloremia was associated with increased mortality in patients who had sustained major trauma.
  
  
  METHODS
  This study enrolled 266 major trauma patients by retrospective chart review, from January 2011 to December 2015. Patients were older than 16 years; were admitted to an intensive care unit; survived more than 48 h; and had sustained major trauma, defined as an injury severity score ≥ 16. Hyperchloremia was defined as a chloride level > 110mEq/L. Delta chloride (Δchloride) was defined as the difference between the serum chloride level measured 48-h post-admission and the initial level. Clinical and laboratory variables were compared between survivors (n = 235) and non-survivors (n = 31). A multivariate logistic regression analysis was performed to assess the association between hyperchloremia 48-h post-admission (hyperchloremia-48) and 30-day mortality.
  
  
  RESULTS
  The overall 30-day mortality was 11.7 % (n = 31). Hyperchloremia-48 occurred in 65 patients (24.4 %) and the incidence was significantly different between survivors and non-survivors (19.6 vs. 61.3 %, respectively, p < 0.001). Multivariate logistic analysis identified hyperchloremia-48 and Δchloride as independent predictive factors for 30-day mortality in major trauma patients.
  
  
  CONCLUSIONS
  Infusion of chloride-rich solutions, such as normal saline, is itself associated with hyperchloremia, which has been associated with poor patient outcomes. Patients receiving normal saline were more likely to suffer major postoperative complications, acute kidney injury, and infections. Moreover, large changes in serum chloride levels correlated with greater in-hospital mortality.
  
  
  CONCLUSIONS
  Hyperchloremia 48-h post-admission and Δchloride was associated with 30-day mortality in major trauma patients. These indices may be useful prognostic markers.
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Tae Hwa
authors.initials: TH
authors.lastname: Hong
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Kyung Won
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Myung Jae
authors.initials: MJ
authors.lastname: Jung
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Jae Gil
authors.initials: JG
authors.lastname: Lee
authors.affiliation: Division of Critical Care and Trauma Surgery, Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea. seunghwan@yuhs.ac.|Trauma Training Center, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea. seunghwan@yuhs.ac.
authors.forename: Seung Hwan
authors.identifier: http://orcid.org/0000-0001-7710-114X
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000137:Acid-Base Imbalance / Q000097:blood / Q000150:complications* / Q000401:mortality*; D000328:Adult; D000368:Aged; D002712:Chlorides / Q000097:blood*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000097:blood* / Q000150:complications / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D002712:Chlorides
keywords: Chloride; Mortality; Normal saline; Resuscitation; Trauma