Predictors of early neurological deterioration in patients with acute ischaemic stroke with special reference to blood urea nitrogen (BUN)/creatinine ratio & urine specific gravity

BACKGROUND & OBJECTIVES: Early neurological deterioration (END) occurs in about 20 to 40 per cent of patients with acute ischaemic stroke and results in increased mortality and functional disability. In recent studies relative dehydration has been found to be associated with END in patients with acute ischaemic stroke. This study was conducted to identify factors useful for predicting END and to assess the role of blood urea nitrogen/creatinine ratio (BUN/creatinine) and urine specific gravity (USG) as predictors of END in patients with acute ischaemic stroke. METHODS: The present study was an observational prospective study. Various parameters comprising demographic, clinical, laboratory and radiological variables along with stroke severity were assessed and studied as predictors of early neurological deterioration in 114 consecutive patients presenting to the Emergency department during 2012. BUN/creatinine >15 and USG >1.010 were studied as markers of relative dehydration contributing to END. RESULTS: Of the 114 patients enrolled in the study, END was observed in 25 (21.9%) patients. National Institutes Health Stroke Scale score (NIHSS) ≥ 12 at admission was found to be an independent risk factor for END. Amongst markers of relative dehydration, BUN/creatinine >15 at admission was found to be an independent risk factor for END, as also USG >1.010. Also, cerebral oedema and size of hypodensity >1/3(rd) of the middle cerebral artery territory on cranial CT were observed to be independent risk factors for END. INTERPRETATION & CONCLUSIONS: Our study findings highlighted a possible association of relative dehydration, as indicated by BUN/creatinine ratio >15, with END along with other parameters like stroke severity at presentation, extent of hypodensity >1/3(rd) of the middle cerebral artery (MCA) territory and cerebral oedema. Dehydration being a treatable condition, the use of BUN/creatinine >15 as a marker of relative dehydration, can be helpful in detecting patients with dehydration early and thus play a role in preventing END.