Background and Aims: Hyponatremia is the predominant electrolyte abnormality with an incidence rate of approximately 22%. It is the leading cause of morbidity and mortality with scarce data in Indian intensive care settings. The aim of this study is to evaluate the clinical features and etiology of hyponatremia in patients admitted to an Intensive Care Unit (ICU) of a tertiary care hospital.
Materials and Methods: A 1-year prospective cross-sectional observational study was conducted, including 100 adult patients with moderate-to-severe hyponatremia admitted to the Medical ICU. Patients underwent investigations such as serum creatinine, blood urea nitrogen, serum osmolality, serum sodium, urine sodium, and urine osmolality, sputum culture, cerebrospinal fluid analysis, and neuroimaging. Data were analyzed using independent sample t-test, Chi-square test, and Fisher\'s exact test.
Results: Vomiting (28) followed by confusion (26) was the most common complaint. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) (46) was the most common etiology for hyponatremia, and euvolemic hypoosmolar hyponatremia (50) was the most common type of hyponatremia. Confusion was significantly high in patients with severe hyponatremia as compared to patients with moderate hyponatremia (22 vs. 4, P < 0.001). In majority of the patients (46), SIADH was the main cause of euvolemic type of hyponatremia (P < 0.001). Increased urine sodium levels were observed in patients with SIADH (46), renal dysfunction (12), and drug-induced etiology (8, P < 0.001).
Conclusion: Patients with hyponatremia secondary to an infectious cause should be meticulously screened for tuberculosis. The timely and effective treatment of hyponatremia is determined by the effective understanding of pathophysiology and associated risk factors of hyponatremia.
Fried LF, Palevsky PM. Hyponatremia and hypernatremia. Med Clin North Am 1997;81:585-609.
Fall PJ. Hyponatremia and hypernatremia. A systematic approach to causes and their correction. Postgrad Med 2000;107:75-82.
Freda BJ, Davidson MB, Hall PM. Evaluation of hyponatremia: A little physiology goes a long way. Cleve Clin J Med 2004;71:639-50.
Han DS, Cho BS. Therapeutic approach to hyponatremia. Nephron 2002;92 Suppl 1:9-13.
Pham PC, Pham PM, Pham PT. Vasopressin excess and hyponatremia. Am J Kidney Dis 2006;47:727-37.
Lindner G, Schwarz C. An update on the current management of hyponatremia. Minerva Med 2012;103:279-91.
Pillai BP, Unnikrishnan AG, Pavithran PV. Syndrome of inappropriate antidiuretic hormone secretion: Revisiting a classical endocrine disorder. Indian J Endocrinol Metab 2011;15 Suppl 3:S208-15.
Marupudi NI, Mittal S. Diagnosis and management of hyponatremia in patients with aneurysmal subarachnoid hemorrhage. J Clin Med 2015;4:756-67.
Rahil AI, Khan FY. Clinical profile of hyponatraemia in adult patients admitted to Hamad General Hospital, Qatar: Experience with 53 Cases. J Clin Diag Res 2009;(3):1419-25.
Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med 2000;342:1581-9.
Chowdhury R, Samanta T, Pan K, Sarkar A, Chakrabarti S. Can hyponatraemia predict mortality in Intensive Care Unit patients: A prospective study in a tertiary care hospital of Kolkata. Int J Med Pharm Sci 2013;3:26-30.
Boscoe A, Paramore C, Verbalis JG. Cost of illness of hyponatremia in the United States. Cost Eff Resour Alloc 2006;4:10.
Patni M, Humaney N, Jeswani J, Deoke S. Clinico-etiological profile of hyponatremia in patients admitted in Intensive Care Unit of tertiary health care rural center. JMSCR 2015;3:6975-82.
Rao MY, Sudhir U, Anil Kumar T, Saravanan S, Mahesh E, Punith K, et al. Hospital-based descriptive study of symptomatic hyponatremia in elderly patients. J Assoc Physicians India 2010;58:667-9.
Vandergheynst F, Sakr Y, Felleiter P, Hering R, Groeneveld J, Vanhems P, et al. Incidence and prognosis of dysnatraemia in critically ill patients: Analysis of a large prevalence study. Eur J Clin Invest 2013;43:933-48.
Sherlock M, O'Sullivan E, Agha A, Behan LA, Rawluk D, Brennan P, et al. The incidence and pathophysiology of hyponatraemia after subarachnoid haemorrhage. Clin Endocrinol (Oxf) 2006;64:250-4.
Mulloy AL, Caruana RJ. Hyponatremic emergencies. Med Clin North Am 1995;79:155-68.
Waikar SS, Mount DB, Curhan GC. Mortality after hospitalization with mild, moderate, and severe hyponatremia. Am J Med 2009;122:857-65.
Chitsazian Z, Zamani B, Mohagheghfar M. Prevalence of hyponatremia in Intensive Care Unit patients with brain injury in Kashan Shahid-Beheshti hospital in 2012. Arch Trauma Res 2013;2:91-4.
Chatterjee N, Sengupta N, Das C, Chowdhuri AR, Basu AK, Pal SK, et al. A descriptive study of hyponatremia in a tertiary care hospital of Eastern India. Indian J Endocrinol Metab 2012;16:288-91.
Agarwal SM, Agrawal A. A comparative study of the clinico-aetiological profile of hyponatremia at presentation with that developing in the hospital. Indian J Med Res 2011;134:118-22.
Miyashita J, Shimada T, Hunter AJ, Kamiya T. Impact of hyponatremia and the syndrome of inappropriate antidiuresis on mortality in elderly patients with aspiration pneumonia. J Hosp Med 2012;7:464-9.
Vurgese TA, Radhakrishan SB, Mapkar OA. Frequency and etiology of hyponatremia in adult hospitalized patients in medical wards of a general hospital in Kuwait. Kuwait Med J 2006;38:211-3.
Padhi R, Panda BN, Jagati S, Patra SC. Hyponatremia in critically ill patients. Indian J Crit Care Med 2014;18:83-7.
Laczi F. Etiology, diagnostics and therapy of hyponatremias. Orv Hetil 2008;149:1347-54.
Panicker GI, Joseph S. A prospective study on clinical profile of hyponatremia in ICU hospitalized patients. Int J Biomed Adv Res 2014;5:297-303.
Vorherr H, Massry SG, Fallet R, Kaplan L, Kleeman CR. Antidiuretic principle in tuberculous lung tissue of a patient with pulmonary tuberculosis and hyponatremia. Ann Intern Med 1970;72:383-7.
Bryant DH. The syndrome of inappropriate secretion of antidiuretic hormone in infectious pulmonary disease. Med J Aust 1972;1:1285-8.
Cockcroft DW, Donevan RE, Copland GM, Ibbott JW. Miliary tuberculosis presenting with hyponatremia and thrombocytopenia. Can Med Assoc J 1976;115:871-3.
Weiss H, Katz S. Hyponatremia resulting from apparently inappropriate secretion of antidiuretic hormone in patients with pulmonary tuberculosis. Am Rev Respir Dis 1965;92:609-16.
Merrill C, Elixhauser A. Hospitalization in the United States, 2002: HCUP Fact Book no. 6. AHRQ Publication no. 05-0056, June 2005. Rockville, MD: Agency for Healthcare Research and Quality; 2005.
Thurman JM, Berl T. Therapy in Nephrology and Hypertension, a Companion to Brenner & Rector's the Kidney. Therapy of dysnatremic disorders. 3rd ed. Philadelphia: Saunders; 2008. p. 337-52.
Liamis G, Kalogirou M, Saugos V, Elisaf M. Therapeutic approach in patients with dysnatraemias. Nephrol Dial Transplant 2006;21:1564-9.
Sharma SK, Mohan A, Banga A, Saha PK, Guntupalli KK. Predictors of development and outcome in patients with acute respiratory distress syndrome due to tuberculosis. Int J Tuberc Lung Dis 2006;10:429-35.