title: Dysnatremia, its correction, and mortality in patients undergoing continuous renal replacement therapy: a prospective observational study.
abstract: BACKGROUND
  Although dysnatremia has been reported to be correlated with mortality risk, this issue remains unresolved in patients undergoing continuous renal replacement therapy (CRRT). Furthermore, it has not been determined whether change in or correction of sodium is related to mortality risk in this subset.
  
  
  METHODS
  A total of 569 patients were prospectively enrolled at the start of CRRT between May 2010 and September 2013. The patients were divided into 5 groups: normonatremia (135-145 mmol/L), mild hyponatremia (131.1-134.9 mmol/L), moderate to severe hyponatremia (115.4-131.0 mmol/L), mild hypernatremia (145.1-148.4 mmol/L), and moderate to severe hypernatremia (148.5-166.0 mmol/L). The non-linear relationship between sodium and mortality was initially explored. Subsequently, the odds ratios (ORs) for 30-day mortality were calculated after adjustment of multiple covariates.
  
  
  RESULTS
  The relationship between baseline sodium and mortality was U-shaped. The mild hyponatremia, moderate to severe hyponatremia, and moderate to severe hypernatremia groups had greater ORs for mortality (1.65, 1.91, and 2.32, respectively) than the normonatremia group (all P values < 0.05). However, later sodium levels (24 and 72 h after CRRT) did not predict 30-day mortality. Furthermore, the changes in sodium over 24 or 72 h, including the appropriate correction of dysnatremia, did not show any relationships with mortality, irrespective of baseline sodium level.
  
  
  CONCLUSIONS
  Sodium level at the start of CRRT was a strong predictor of mortality. However, changes in sodium level and the degree of sodium correction were not associated with the mortality risk in the patients with CRRT.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea.
authors.forename: Seung Seok
authors.initials: SS
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea.
authors.forename: Eunjin
authors.initials: E
authors.lastname: Bae
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea.|Kidney Research Institute, Seoul National University College of Medicine, 03080, Seoul, South Korea.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea.|Kidney Research Institute, Seoul National University College of Medicine, 03080, Seoul, South Korea.
authors.forename: Yon Su
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea.|Kidney Research Institute, Seoul National University College of Medicine, 03080, Seoul, South Korea.
authors.forename: Jin Suk
authors.initials: JS
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehakro, Jongno-gu, Seoul, 03080, South Korea. junephro@snu.ac.kr.|Kidney Research Institute, Seoul National University College of Medicine, 03080, Seoul, South Korea. junephro@snu.ac.kr.
authors.forename: Kwon Wook
authors.initials: KW
authors.lastname: Joo
mesh_terms: D058186:Acute Kidney Injury / Q000628:therapy; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006955:Hypernatremia / Q000097:blood* / Q000401:mortality*; D007010:Hyponatremia / Q000097:blood* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017582:Renal Replacement Therapy; D012720:Severity of Illness Index; D012964:Sodium / Q000097:blood*
chemical_list: D012964:Sodium