title: Insights about serum sodium behavior after 24 hours of continuous renal replacement therapy.
abstract: OBJECTIVE
  The aim of this study was to investigate the clinical and laboratorial factors associated with serum sodium variation during continuous renal replacement therapy and to assess whether the perfect admixture formula could predict 24-hour sodium variation.
  
  
  METHODS
  Thirty-six continuous renal replacement therapy sessions of 33 patients, in which the affluent prescription was unchanged during the first 24 hours, were retrieved from a prospective collected database and then analyzed. A mixed linear model was performed to investigate the factors associated with large serum sodium variations (≥ 8mEq/L), and a Bland-Altman plot was generated to assess the agreement between the predicted and observed variations.
  
  
  RESULTS
  In continuous renal replacement therapy 24-hour sessions, SAPS 3 (p = 0.022) and baseline hypernatremia (p = 0.023) were statistically significant predictors of serum sodium variations ≥ 8mEq/L in univariate analysis, but only hypernatremia demonstrated an independent association (β = 0.429, p < 0.001). The perfect admixture formula for sodium prediction at 24 hours demonstrated poor agreement with the observed values.
  
  
  CONCLUSIONS
  Hypernatremia at the time of continuous renal replacement therapy initiation is an important factor associated with clinically significant serum sodium variation. The use of 4% citrate or acid citrate dextrose - formula A 2.2% as anticoagulants was not associated with higher serum sodium variations. A mathematical prediction for the serum sodium concentration after 24 hours was not feasible.
authors.affiliation: Unidade de Terapia Intensiva, Hospital Sírio-Libanês, São Paulo, SP, Brazil.
authors.forename: Thiago Gomes
authors.initials: TG
authors.lastname: Romano
authors.affiliation: Unidade de Terapia Intensiva, Hospital Baia Sul, Florianópolis, SC, Brazil.
authors.forename: Cassia Pimenta Barufi
authors.initials: CP
authors.lastname: Martins
authors.affiliation: Unidade de Terapia Intensiva, Hospital Sírio-Libanês, São Paulo, SP, Brazil.
authors.forename: Pedro Vitale
authors.initials: PV
authors.lastname: Mendes
authors.affiliation: Unidade de Terapia Intensiva, Departamento de Emergência, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Bruno Adler Maccagnan Pinheiro
authors.initials: BA
authors.lastname: Besen
authors.affiliation: Unidade de Terapia Intensiva, Departamento de Emergência, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Fernando Godinho
authors.initials: FG
authors.lastname: Zampieri
authors.affiliation: Unidade de Terapia Intensiva, Departamento de Emergência, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D019343:Citric Acid / Q000008:administration & dosage; D016208:Databases, Factual; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D006955:Hypernatremia / Q000150:complications* / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017582:Renal Replacement Therapy / Q000379:methods*; D012964:Sodium / Q000097:blood*
chemical_list: D000925:Anticoagulants; C002113:acid citrate dextrose; D019343:Citric Acid; D012964:Sodium; D005947:Glucose