CLINICO ETIOLOGICAL PROFILE OF HYPONATREMIA IN IMCU OF KANNIYAKUMARI GOVERNMENT MEDICAL COLLEGE

Eunice S 1 , Christopher Nesamony 2 , Thirukumareswaran Vijayan 3 , Suhas Raj Sivakumar 3 and Sindhu Neelakandan 3 . 1. Assistant Professor of Medicine, Kanniyakumari Govt. Medical College. 2. Professor of Medicine , Kanniyakumari Govt. Medical College. 3. Postgraduate in General Medicine , Kanniyakumari Govt. Medical College. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


Materials and Methods:-
100 consecutive cases who had serum Sodium levels of <130 mmol/L were identified and studied during a period of 12 months from Jan 2016 to Dec 2016. The patients of age 15 years or more and who were hyponatremic on admission were included in the study. Patients who developed hyponatremia during hospital stay were excluded. Detailed history including onset , duration, and progression of symptoms, history of illnesses such as congestive cardiac failure, chronic kidney disease, chronic liver disease, hypothyroidism, hypopituitarism, pneumonia, malignancies were recorded. History of drugs causing hyponatremia like diuretics, antidepressants, anticonvulsants, chemotherapeutic agents, and NSAIDS were taken and detailed general and physical examinations of the patients were done.

Na-Sodium; K-Potassium; BUN-Blood urea nitrogen
Other tests included urine sodium, osmolality, serum cortisol, ACTH level, thyroid function test, liver function test.
After establishing the diagnosis of hyponatremia, the patients were categorized based on the level of hyponatremia into mild, moderate and severe hyponatremia. [6][7][8] 126-130 mmol/l -Mild 121-125 mmol/l -Moderate ≤ 120 mmol/l -Severe They were then further evaluated to find out the etiology. Serum and urine osmolality was calculated. Normal serum osmolality is 275-295 mosm/kg H 2 O (13) . They were then assessed clinically to find out the volume status clinically if they had low serum osmolality.
Those patients who had no signs mentioned above was considered to be euvolemic. Student's t-test and analysis of variance (ANOVA) were statistical methods used to analyse continous variables. Chi square test and Fisher's exact test were used to analyse categorical variables. The study protocol was approved by the ethical committee.

Results:-
In the present study of 100 patients 48 were males and 52 were females.

Sex distribution
The patients were between 15-85 years of age, predominantly between 65-85 years.

Discussion:-
Hyponatremia is a common clinical problem which is being increasingly recognized in all departments. The management is highly rewarding as the patient comes back to a near normal state of health. At the same time, over treatment is also dangerous as it can lead to permanent neurological damage. As hyponatremia is becoming an increasingly common clinical state, a proper systematic study of the causes, management and outcome of hyponatremia is timely. Our study throws light to all the aspects.
Of the 100 patients studied, 48% were male 52% were female. The female preponderance in our study correlates well with most of the other studies. Mean age group is 68.34 years. It is well known that older group patients are more liable for metabolic abnormalities and a small tilt in metabolic stability will make them more symptomatic.
The prevalence of severe hyponatremia (<120 mmol/L), formed the major group which is in contrast to other studies by Thomas et al 9 , Gross et al 10 and Hochman et al 11 who had mild to moderate cases as the predominant group. This stresses the fact that hyponatremia is recognized and diagnosed quite late in our country. Lowest serum sodium was 100 mmol/L. Mean serum sodium at the time of presentation was 118mmol/L.

Causes of hypoosmolar hypervolemic hyponatremia
Causes of hypoosmolar hypervolemic hyponatremia 1269 In our study SIADH was the commonest cause of hyponatremia. Respiratory diseases like pneumonia (25.64%) followed by CVA (23.07%) was the commonest etiological factor for SIADH. This is comparable with other studies by Thomas et al 9 , Gross et al 10 , and Hochman et al 11 .
Cardiac failure was one of the important causes in other studies. In our study it was only 2%, which is in contrast to 18%, 13% and 25% by Thomas et al 9 , Hochman et al 10 and Gross et al 11 respectively. Other possible explanation being, patients with mild congestive heart failure are increasingly being treated in outpatient clinics. But our study is comparable with the study by Minneke. J. Coenradl et al 12 .
Majority of patients (62.9%) with hypoosmolar hypovolemic hyponatremia is due to extra renal loss which is comparable with other studies.
Many drugs produce SIADH. In our study anti depressants were the commonest cause which is comparable with other studies. Six patients who had hypoosmolar euvolemic hyponatremia were due to hypothyroidism which is comparable with other studies.
It is not difficult to diagnose hyponatremia who present with acute symptoms. It is important to recognize those patients without much symptoms, some of them having chronic hyponatremia and it is important to correct them at a slower pace.
63% of our patients were symptomatic and the rest 37% were asymptomatic. The major clinical presentation among those symptomatic was altered sensorium accounting for 45%.
23% had chronic hyponatremia which included patients with serum sodium <125 mmol/L and mild or no symptoms. The major causes include chronic renal failure and cirrhosis. Hence it is evident that it is very important to study serum electrolytes in patients who are having chronic illness.
We followed up the patient till the discharge or death of the patient with twice daily measurement of serum sodium and serial monitoring of other parameters. No complications of treatment was noted in our study.
The mean hospital stay of our patients was 11.6 days. The morality is our study group was 5%. The cause of morality include squamous cell carcinoma of lung, sepsis, hepatic failure, meningitis and periampullary carcinoma. It is well observed that death is due to underlying primary conditions and not due to hyponatremia itself.

1270
Our study shows that many people had serum sodium of <120mmol/L which we considered as severe hyponatremia. Such severe hyponatremia was not observed in many foreign studies. Treatment of hyponatremia is highly rewarding.
The mortality in our study group is 5% and most of them were due to the underlying primary disease and not due to hyponatremia itself.
It is necessary to recognize such an increasing electrolyte abnormality and to correct them. The common causes and the management protocol should be available in every IMCU.