Incidence, risk factors, and clinical outcomes of mannitol-induced acute kidney injury among acute stroke patients admitted to East Avenue Medical Center

BackgroundIn the Philippines, stroke is the second most common cause of mortality and is among the five leading causes of disability. Mannitol, a hyperosmolar agent, is a mainstay for the treatment of brain edema caused by elevated intracranial pressure in acute stroke patients. It is a potent diuretic that may trigger intravascular volume depletion, electrolyte imbalance, and renal tubular damage, which may lead to acute kidney injury in acute stroke. ObjectiveThis study aims to describe the incidence, identify the risk factors, and determine the clinical outcomes of mannitol-induced acute kidney injury among acute stroke patients admitted to East Avenue Medical Center from January 1, 2019, to December 31, 2021. MethodsThis is a retrospective study conducted at the East Avenue Medical Center, a tertiary training hospital in Quezon City, Philippines. A three-year chart review of acute stroke patients who developed mannitol-induced acute kidney injury (MI-AKI) was conducted. ResultA total of 348 eligible acute stroke patients were included in the study. Of these, 60 patients (17%) developed MI-AKI during confinement. There was a higher predominance among males than females with more than half of patients (65%) belonging to the 40 to 59 years age group. The risk factors identified were high National Institutes of Health Stroke Scale (NIHSS) score, chronic kidney disease, possibly cardiovascular disease, such as heart failure, intraparenchymal type hemorrhagic stroke, and high mannitol infusion dose >0.40g/kg in more than 48 hours. A high mortality rate was observed among MI-AKI patients in the study as compared with those without AKI (61.67% vs 27.43%, P<0.001) whereas spontaneous resolution of AKI was seen in 25 patients (41.67%, P<0.001). Only 4 patients (6.67%, P=0.001) who had renal replacement therapy had worsening renal function compared to the 27 patients (45%, P<0.001) who did not receive renal replacement therapy. ConclusionRisk factors for MI-AKI include moderate to severe NIHSS score, chronic kidney disease 3 and above, cardiovascular disease, and high-dose mannitol infusion. Early nephrology referral among patients with mannitol infusion for stroke is a must among patients who have co-morbidities including chronic kidney disease stage 3 and above, and cardiovascular disease such as heart failure. Serial monitoring of renal function should be performed especially for those patients with moderate to severe NIHSS scores and high-dose mannitol infusion for appropriate dosing to prevent MI-AKI.