Hyper/hypoglycemia and acute kidney injury in critically ill patients

Background & aims: Abnormalities of blood glucose (BG) concentration (hyper- and hypoglycemia), now referred to with the cumulative term of dysglycemia, are frequently observed in critically ill patients, and significantly affect their clinical outcome. Acute kidney injury (AKI) may further complicate glycemic control in the same clinical setting. This narrative review was aimed at describing the pathogenesis of hyper- and hypoglycemia in the intensive care unit (ICU), with special regard to patients with AKI. Moreover, the complex relationship between AKI, glycemic control, hypoglycemic risk, and outcomes was analyzed. Methods: An extensive literature search was performed, in order to identify the relevant studies describing the epidemiology, pathogenesis, treatment and outcome of hypo- and hyperglycemia in critically ill patients with AKI. Results and conclusion: Patients with AKI are at increased risk of both hyper-and hypoglycemia. The available evidence does not support a protective effect on the kidney by glycemic control protocols employing Intensive Insulin Treatment (IIT), i.e. those aimed at maintaining normal BG concentrations (80-110 mg/dl). Recent guidelines taking into account the high risk for hypoglycemia associated with IIT protocols in critically ill patients, now suggest higher BG concentration targets (<180 mg/dl or 140-180 mg/dl) than those previously recommended (80-110 mg/dl). Notwithstanding the limited evidence available, it seems reasonable to extend these indications also to ICU patients with AKI.