Hyponatremia in critically ill patients

Abstract

Context:Hyponatremia is a common electrolyte disturbance in critically ill hence understanding its implications is important.Aims:This study was carried out to ascertain frequency, predisposing conditions and outcome in critically ill patients with hyponatremia on intensive care unit (ICU) admission.Settings and Design:This was an observational, prospective study of a series of ICU patients during a 12-month period.Materials and 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.Statistical Analysis Used: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.

Hyponatremia in critically ill mechanically ventilated children

“…This observation is similar to study done by Padhi R et al in which septicemia was the leading cause of hyponatremia in this study; no significant difference was noted in study groups regarding serum sodium levels. 4 Already admitted subjects showed significantly higher duration of illness (23.7±59.3 days) compared to newly admitted subjects (9.4±19.8 days) (p <0.01). Frequency of subjects with different systems involved was noted in both study groups.…”

“…Padhi R et al conducted a prospective study of series of ICU patient for 12 month period in total 730 patients and found the frequency of hyponatremia on ICU admission was 34.3%. 4 Alicia K. Au et al performed a retrospective analysis of postoperative admission to pediatric intensive care unit in total 145 children (116 received hypotonic and 29 received normotonic fluid) 11% were hyponatremic. 8 A study by Fenk et al involving 151486 adult patients from 77 ICU's over 10 years noted that severity of hyponatremis in ICU is associated with poor outcome in graded fashion.…”

“…36.25% of hyponatremic patients met the criteria of SIADH, (Padhi R et al). 4 Severe sepsis (sepsis with acute organ dysfunction) was the most common leading to hyponatremia probably due to SIADH, although the cause is not known but it may be related to dilution of extracellular space and retained exogenous fluid. Valentine SL et al on study of 168 children with acute lung injury got positive fluid balance on day 3 is independent associated with fewer ventilator-free days and greater fluid load at initiation of continuous renal replacement therapy associated with higher mortality.…”

“…2,3 Hyponatremia can be classified on the basis of serum osmolality, volume status and urinary sodium into hypertonic, isotonic and hypotonic types. Hyponatremia may also be classified into hypervolemic, euvolemic and hypovolemic as follows: 4  Hypovolemic hyponatremia: Decreased total body sodium and decreased total body water. The sodium deficit exceeding water deficit.…”

To Study the Clinical Outcome of Hyponatraemia in Icu Setting

“…1 Prevalence of hyponatraemic patients is 3.5%-40.0%. [2][3][4] The commonest cause of euvolemic hyponatremia is SIADH, other causes being diuretics, CCF and liver disorder, etc. [5][6] Hyponatremia is classified as hypovolemic, euvolemic and hypervolemic.…”