Prevalence of Hyponatremia in Neurosurgical Patients in South India – An Institution-Based Observational Study

Abstract

BACKGROUND Hyponatremia is the most frequently encountered electrolyte abnormality in hospitalized patients, especially those with neurological injury. Acute onset hyponatremia is common in patients with any type of cerebral insult including traumatic brain injury (TBI), subarachnoid haemorrhage (SAH) and brain tumours. Also seen as a complication of intracranial procedures, contributing to increased morbidity and mortality. Early diagnosis and effective management can reduce mortality associated with this condition. This study was done to estimate the prevalence of hyponatremia in neurosurgical patients in our institution. METHODS This is an observational study that analysed the adult patients admitted to the neuro intensive care unit (ICU) after having undergone the neurosurgical procedure from January 2019 to July 2019. A structured questionnaire was used for data collection. The prevalence of hyponatremia was calculated with preoperative serum sodium levels in the study population. RESULTS In this study with 61 patients undergoing neurosurgical procedures, the prevalence of hyponatremia was 34.4 %. The majority of patients for surgery comes between 41 to 50 years. 57.4 % cases were with traumatic brain injury, 11.5 % cases were with sub arachnoid haemorrhage and 31.1 % were with intracranial tumour. 26 % of hyponatremia patients belonged to mild grade while 8 % to moderate grade. 62.5 % of patients above 70 years, 44.4 % of patients between 51 to 60 years and 40 % of patients between 61 and 70 years presented with mild hyponatremia. 37.5 % of patients above 70 years and 10 % of patients between 61 and 70 years presented with moderate hyponatremia. CONCLUSIONS Our study showed an increased prevalence of hyponatremia in neurosurgical patients which demand effective approaches for an accurate and timely diagnosis of this electrolyte disorder. Hyponatremia frequently occurs in patients with TBI, SAH and intracranial tumours. It is also essential to differentiate between syndrome of inappropriate antidiuretic hormone (SIADH) and cerebral salt wasting syndrome (CSW) as the treatment modalities are entirely different for these two entities. Early detection, close monitoring, etiological evaluation and prompt treatment based on aetiology can reduce the complications and improve patient’s outcomes. KEYWORDS Electrolyte Abnormality; Brain Injury, Morbidity