Acute kidney injury

Acute kidney injury (AKI), previously called acute renal failure (ARF), is an abrupt loss of kidney function that develops within 7 days.

Its causes are numerous. Generally it occurs because of damage to the kidney tissue caused by decreased kidney blood flow (kidney ischemia) from any cause (e.g., low blood pressure), exposure to substances harmful to the kidney, an inflammatory process in the kidney, or an obstruction of the urinary tract that impedes the flow of urine. AKI is diagnosed on the basis of characteristic laboratory findings, such as elevated blood urea nitrogen and creatinine, or inability of the kidneys to produce sufficient amounts of urine.

AKI may lead to a number of complications, including metabolic acidosis, high potassium levels, uremia, changes in body fluid balance, and effects on other organ systems, including death. People who have experienced AKI may have an increased risk of chronic kidney disease in the future. Management includes treatment of the underlying cause and supportive care, such as renal replacement therapy.

acute kidney injury (AKI) is due to: a) decreased extracellular volume+vasoactive substances→renal vasoconstriction and

b) ferrihemate, which is formed from myoglobin at a pH < 5.6

Eagle et al., performed a post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial data set (clinical trial registration no.: NCT00111085, https://clinicaltrials.gov). The primary outcome of interest was the development of acute kidney injury, which was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Secondary outcomes of interest were death and a modified Rankin Scale score greater than 2 at 12 weeks post-aSAH. Propensity score matching was used to assess for a significant treatment effect related to clazosentan administration and AKI. Univariate analysis, locally weighted scatterplot smoothing (LOWESS) curves, and stepwise logistic regression models were used to evaluate for associations between baseline or disease-related characteristics and study outcomes.

One hundred fifty-six (38%) of the 413 patients enrolled in the CONSCIOUS-1 trial developed AKI during their ICU stay. A history of hypertension (p < 0.001) and the number of nephrotoxic medications administered (p = 0.029) were independent predictors of AKI on multivariate analysis. AKI was an independent predictor of death (p = 0.028) but not a poor functional outcome (p = 0.21) on multivariate testing. Unresolved renal dysfunction was the strongest independent predictor of death in this cohort (p < 0.001).

AKI is a common complication following aneurysmal subarachnoid hemorrhage. Patients with premorbid hypertension and those treated with nephrotoxic medications may be at greater risk for renal dysfunction. Acute kidney injury (AKI) appears to confer an increased probability of death after aSAH ¹⁾.

It is a clinically common and severe complication of ischemia reperfusion injury, associated with high morbidity and mortality rates, and prolonged hospitalization. Rapamycin is a type of macrolide, primarily used for anti‑rejection therapy following organ transplantation and the treatment of autoimmune diseases. Rapamycin has been identified to exert a protective effect against AKI induced by renal I/R as an autophagy inducer. However, whether rapamycin preconditioning may relieve AKI following cerebral I/R (CIR) remains to be fully elucidated. The purpose of the present study was to investigate the effects of CIR on the renal system of rats and the role of rapamycin in AKI following CIR. In the present study, a CIR model was established in Sprague‑Dawley rats via a 90‑min period of middle cerebral artery occlusion and 24 h reperfusion, and pretreatment with an intraperitoneal injection of rapamycin (dosage: 1 mg/kg; 0.5 h) prior to CIR. The levels of serum creatinine and blood urea nitrogen (BUN), and the expression of inflammation‑, apoptosis‑ and autophagy‑associated markers were subsequently measured. In addition to certain histopathological alterations to the kidney, it was identified that CIR significantly increased the levels of serum creatinine, BUN, tumor necrosis factor‑α and interleukin‑1β, and significantly induced apoptosis and autophagy. It was observed that rapamycin induced autophagy through the mammalian target of rapamycin complex 1/autophagy‑related 13/unc‑51 like autophagy activating kinase 1 signaling pathway, and that rapamycin pre‑treatment significantly improved renal function and alleviated renal tissue inflammation and cell apoptosis in rats following CIR. In conclusion, the results suggested that rapamycin may alleviate AKI following CIR via the induction of autophagy ²⁾.