Cerebral salt wasting syndrome (CSWS) and Syndrome of Inappropriate Anti Diuretic Hormone secretion (SIADH) are the most common aetiological factors for developing hyponatremia following stroke. The differentiation of these two entities is crucial as the treatment options are completely different. Hence the knowledge on predictors of CSWS is important to make a more accurate diagnosis of CSWS.
Two hundred and fourty six patients with confirmed stroke were prospectively observed throughout the hospital stay in a tertiary referral center in Sri Lanka to identify the possible predictors of CSWS. Hyponatremia was defined as serum Na+ level less than 131mmo/l. Serum osmolality, urine osmolality, urinary Na+, serum cortisol and thyroid function tests were performed on all the hyponatremic patients. Differentiation of the CSWS and SIADH was based on physical examination findings and laboratory parameters.
The incidence of hyponatremia in our study population was 19.1% (95% Confidence Interval 14.39-24.58). The majority of patients (24, 51%) were attributed to CSWS. SIADH group comprised of 17 (36.2%) patients and 6 (12.7%) patients had other undetermined causes. There was a significant statistical difference between the aetiologies of hyponatremia and laboratory investigations like urinary Na+, urinary osmolality and serum osmolality. Demographic characteristics, comorbidities, imaging findings and clinical parameters like systolic blood pressure, diastolic blood pressure, on admission GCS were considered in the multivariable logistic regression model and the overall model was not significant.
The incidence of CSWS is higher than the incidence of SIADH. The demographic characteristics, comorbidities, imaging and clinical parameters like blood pressure, on admission GCS could not predict the occurrence of CSWS