title: Hyponatremia in critically ill patients.
abstract: BACKGROUND
  Hyponatremia is a common electrolyte disturbance in critically ill hence understanding its implications is important.
  
  
  OBJECTIVE
  This study was carried out to ascertain frequency, predisposing conditions and outcome in critically ill patients with hyponatremia on intensive care unit (ICU) admission.
  
  
  METHODS
  This was an observational, prospective study of a series of ICU patients during a 12-month period.
  
  
  METHODS
  THE PATIENTS WERE DIVIDED INTO TWO GROUPS: Hyponatremic (serum sodium < 135 mmol/L) and Eunatremic groups (135-145 mmol/L). Clinical examination included volume status and drug history, biochemistries, clinical diagnosis and cause of hyponatremia.
  
  
  METHODS
  Fisher's exact test, unpaired t-tests Wilcoxon ranksum tests, profile-likelihood method, log-rank test and Kaplan-Meier curves were used. P < 0.05 were considered to be statistically significant.
  
  
  RESULTS
  In the hyponatremic group, the frequency of hyponatremia on ICU admission was 34.3%, most were euvolumic, 58.96%. Females comprised of 36.5%. The mean age was 60.4 ± 17.2. The Syndrome of inappropriate Antidiuretic Hormone (SIADH) criteria was met in ninety-one patients (36.25%), peumonia being the leading cause of SIADH. Patients with severe sepsis, elective surgery patients, renal failure and heart failure, cirrhosis of liver and subarachnoid hemorrhage were other more likely etiologic causes (P < 0.05). The hyponatremic group spent a longer time in the ICU (P = 0.02), had longer mechanical ventilator days (P < 0.05) and had an increased mortality rate (P = 0.01).
  
  
  CONCLUSIONS
  Hyponatremia present on admission to the ICU is independent risk factors for poor prognosis.
authors.affiliation: Department of Medicine, Division of Critical Care, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Padhi
authors.affiliation: Department of Medicine, Division of Critical Care, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India.
authors.forename: Baikuntha Nath
authors.initials: BN
authors.lastname: Panda
authors.affiliation: Department of Medicine, Division of Critical Care, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India.
authors.forename: Snehalata
authors.initials: S
authors.lastname: Jagati
authors.affiliation: Department of Anaesthesia, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India.
authors.forename: Subhas Chandra
authors.initials: SC
authors.lastname: Patra
keywords: Critically ill; epidemiology; hyponatremia