title: [Hyponatremia upon admission in patients over 65 years of age. Relation with medium length of stay and hospital mortality].
abstract: OBJECTIVE
  To determine the relation between natremia levels equal to or lower than 130 mEq/l upon admission, and average length of stay and hospital mortality in patients with more than 65 years of age.
  
  
  METHODS
  Prospective case-control study lasting one year.
  
  
  METHODS
  Complejo Hospitalario San Millán-San Pedro (second-level hospital) in Logroño (La Rioja).
  
  
  METHODS
  
  
  
  METHODS
  patients with more than 65 years of age and natremia levels equal to or lower than 130 mEq/l upon admission.
  
  
  METHODS
  normonatremic patients matched by age and sex.
  
  
  METHODS
  average length of stay and hospital mortality. Comparative tests: Z-test comparing two mean values and Yate's chi-square continuity correction.
  
  
  RESULTS
  With a 95% confidence, we have verified that the average length of stay of hyponatremic patients is between 1.44 and 9.2 days longer than in the case of normonatremic patients and the mortality rate is between 2.1 and 28.1% greater.
  
  
  CONCLUSIONS
  Patients with hyponatremia upon admission have a longer average length of stay and a greater mortality. Plasmatic sodium levels equal to or lower than 130 mEq/l upon admission are associated to a poor prognosis in the latter evolution of the patient.
authors.affiliation: Unidad Docente de Medicina Familiar y Comunitaria, Complejo Hospitalario, San Millán-San Pedro, Logroño.
authors.forename: A
authors.initials: A
authors.lastname: García Segura
authors.forename: C
authors.initials: C
authors.lastname: Gadea Ruiz
authors.forename: B
authors.initials: B
authors.lastname: Oliva Fanlo
authors.forename: R
authors.initials: R
authors.lastname: Ruiz Rodríguez
authors.forename: F
authors.initials: F
authors.lastname: Antón Botella
authors.forename: J
authors.initials: J
authors.lastname: Pinilla Moraza
authors.forename: J
authors.initials: J
authors.lastname: San Román Lazcano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007010:Hyponatremia; D007297:Inpatients; D007902:Length of Stay; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies
vernacular_title: Hiponatremia al ingreso en pacientes mayores de 65 años. Relación con la estancia media y la mortalidad hospitalaria.