Global epidemiology and outcomes of acute kidney injury

Abstract

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to decreased kidney function. In addition to retention of waste products, impaired electrolyte homeostasis and altered drug concentrations, AKI induces a generalized inflammatory response that affects distant organs. Full recovery of kidney function is uncommon, which leaves these patients at risk of long-term morbidity and death. Estimates of AKI prevalence range from <1% to 66%. These variations can be explained by not only population differences but also inconsistent use of standardized AKI classification criteria. The aetiology and incidence of AKI also differ between high-income and low-to-middle-income countries. High-income countries show a lower incidence of AKI than do low-to-middle-income countries, where contaminated water and endemic diseases such as malaria contribute to a high burden of AKI. Outcomes of AKI are similar to or more severe than those of patients in high-income countries. In all resource settings, suboptimal early recognition and care of patients with AKI impede their recovery and lead to high mortality, which highlights unmet needs for improved detection and diagnosis of AKI and for efforts to improve care for these patients.

Alternate abstract:

Key points

Acute kidney injury (AKI) is a syndrome encompassing a wide variety of aetiologies and pathophysiologic processes leading to decreased kidney function.

The Kidney Disease: Improving Global Outcomes classification stages AKI into three levels of severity on the basis of increases in serum creatinine level, decreased urine output or need for renal replacement therapies.

In high-resource settings, AKI occurs in one in five hospitalized adult patients, which is approximately half of adult patients receiving intensive care, and in one in four paediatric patients receiving intensive care.

Each episode of AKI is associated with considerable mortality and long-term adverse outcomes, including cardiovascular complications, chronic kidney disease and end-stage renal disease.

In low-resource settings, AKI is often caused by environmental factors such as contaminated water and endemic infections; public health interventions are essential to decrease its incidence and complications.

In low-resource settings, AKI recognition, diagnosis and treatment initiation are often delayed or inadequate, leading to avoidable increases in mortality, severe complications and cost.