Clinical features, outcome and cost of hyponatremia-associated admission and hospitalization in elderly and very elderly patients: a single-center experience in Turkey.
OBJECTIVE
Hyponatremia is a common electrolyte disorder in hospitalized patients. Clinical features, outcome and cost of hyponatremia-associated admission and hospitalization in elderly and very elderly patients are not well known.


METHODS
Elderly (>64 years) patients admitted to the emergency department (ED) and hospitalized between January 1, 2010, and December 31, 2010, were evaluated. Hyponatremia was defined as serum sodium level below 135 mmol/L. Hyponatremic patients were divided into two groups: group 1 (n = 150, 65-74 years old) and group 2 (n = 103, >74 years old).


RESULTS
A total of 4,960 patients above 65 years of age admitted to ED and hospitalized were included. Prevalence of ED in group 1 and group 2 was 4.1 % (150/3,651) and 7.8 % (103/1,309), respectively (p < 0.001). Vomiting and diarrhea were the most important complaints. A total of 111 (43.8 %) patients were being treated with renin-angiotensin system (RAS) blockers. Mortality, morbidity and hospital cost increased in parallel to decrease in serum Na(+) level and increase in age. Group 2 subjects had not only higher intensive care need (p < 0.01) and mortality rates (p < 0.01), but also higher hospital cost burden (p < 0.05) compared to group 1. Alzheimer's disease was one of the most common co-morbidity in patients, particularly in group 2 (5.3 % vs. 21.3 %, p < 0.001).


CONCLUSIONS
Hyponatremia-associated hospitalization is an important and potentially lethal condition in elderly and very elderly patients. Clinicians should be careful when prescribing RAS blockers and diuretics in elderly patients.
Division of Nephrology, Department of Internal Medicine, School of Medicine, Mersin University, 33079 Mersin, Turkey. k.turgutalp@hotmail.com
K
K
Turgutalp
O
O
Ozhan
E
E
Gok Oguz
M
M
Horoz
A
A
Camsari
A
A
Yilmaz
A
A
Kiykim
M
M
Arici
D058186:Acute Kidney Injury / Q000453:epidemiology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D057911:Angiotensin Receptor Antagonists / Q000009:adverse effects; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects; D016470:Bacteremia / Q000453:epidemiology; D003422:Critical Care / Q000706:statistics & numerical data; D003967:Diarrhea / Q000150:complications; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D017721:Hospital Costs / Q000706:statistics & numerical data*; D006801:Humans; D007010:Hyponatremia / Q000191:economics / Q000209:etiology* / Q000401:mortality*; D007902:Length of Stay / Q000191:economics / Q000706:statistics & numerical data; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012964:Sodium / Q000097:blood; D049993:Sodium Chloride Symporter Inhibitors / Q000009:adverse effects; D018709:Statistics, Nonparametric; D013997:Time Factors; D014421:Turkey / Q000453:epidemiology; D014839:Vomiting / Q000150:complications
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D049993:Sodium Chloride Symporter Inhibitors; D012964:Sodium