Complications Associated with Osmotic Therapy in Acute Stroke Patients- A Prospective Longitudinal Observational Study

Introduction: Mannitol is one of the most frequently used drugs to treat cerebral oedema resulting from ischemic and haemorrhagic strokes. Mannitol administration is associated with complications such as Acute Kidney Injury (AKI) and electrolyte imbalance. Aim: To study effect of mannitol therapy on electrolyte levels and renal function in acute stroke patients. Materials and Methods: The present prospective longitudinal observational study was carried out from January 2019 till September 2019 in Father Muller Medical College, Mangalore, India. After taking informed consent, patients with acute stroke who received mannitol were recruited into the study. Nature of the stroke, presence of comorbidities and dosage of mannitol given were recorded. Serum electrolytes, Serum urea and creatinine were recorded at admission and on fifth day. Serum urea was measured by enzymatic photometric method using urease and glutamate dehydrogenase and serum creatinine was measured by Jaffe’s kinetic method. Comparison of data among different groups was performed using student t-test, ANOVA test, Mann-whitney test and Pearson test. The p-values <0.05 were taken as statistically significant. Results: Total of 72 patients were included in the study. Mean age was 57.7±14.6 years and male: female ratio was 2.27:1. Of the total study subjects, 16 suffered from diabetes (22.22%), 40 from hypertension (55.55%). Ischemic stroke was seen in 41.66% patients and haemorrhagic stroke was seen in 58.33% of the patients. The dose of mannitol administered to all the patients was less than 1 gram/kg/day (low dose mannitol). Cumulative dose of mannitol was 180±177.3 grams. Serum sodium levels were significantly lower on fifth day compared to admission (p-value 0.030) whereas serum potassium and chloride levels were not significantly changed during therapy. There was statistically significant elevation in serum urea levels from admission to fifth day (p-value <0.001) whereas creatinine levels were not significantly altered. Total cumulative dose was compared to serum electrolyte levels and urea and creatinine at admission and fifth day and no significant changes were found. On analysing comorbidities, electrolyte fluctuations were more common in diabetics and Chronic Kidney Disease (CKD) patients whereas renal function parameters were abnormal in diabetics, CKD and hypertensive patients. None of the patients needed any corrective measures to treat the dyselectrolytemias or altered renal function. Conclusion: Low dose mannitol therapy does not produce any significant electrolyte or renal function abnormality in patients with acute stroke. Careful monitoring may be required while treating patients with additional comorbidities.