Comparing incidence of major abdominal nonvascular surgery: associated AKI defined by the diagnoses criteria RIFLE, AKIN and KDIGO

Abstract

Acute kidney injury (AKI), a frequent complication in hospitalized patients, is a complex syndrome occurring in many clinical situations, which can be manifested from mild increases serum creatinine (SCr) to anuric kidney failure. In intensive care units (ICU) patients its frequency can reach up to 50%. It has been difficult to do comparisons among different studies and to generalize its results due to the large number of different definitions that have been used for AKI diagnosis. Therefore, new diagnosis criteria were proposed aiming to standardize AKI diagnosis, and two new definitions were developed, RIFLE (Risk, Injury, Failure, Loss and End-Stage Kidney Disease) and AKIN (Acute Kidney Injury Network). Both definitions use small and abrupt increase in SCr and urinary output decrease for AKI diagnosis. The recently launched AKI Kidney Disease: Improving Global Outcomes (KDIGO) Guidelines proposed a new criterion, aiming to harmonize the two previous definitions. According to KDIGO, AKI is defined as an increase of SCr e 0.3 mg/dL within 48 hours, or a SCr increase e 50% from baseline, which is known or presumed to have occurred within the prior 7 days, or urine volume < 0.5 mL/kg/h for 6 hours. We propose an exploratory study aimed to determine the differences in the incidence of AKI defined by the RIFLE criteria diagnoses, and AKIN, KDIGO in patients undergoing major, elective, abdominal, non-vascular surgeries. It will be a prospective, exploratory, quantitative field research study, to be performed in 1,000 patients e 18 years old, who were submitted to major, elective, abdominal, non-vascular surgeries, and who had their pos-op in two surgical ICUs for adults at the Hospital das Clínicas da Faculdade de Medicina da USP. These patients will be studied throughout the first seven days of ICU hospitalization (or until discharge, if it happens before seven days). SCr will be assessed at the pre-op time, at ICU admission, and daily for seven days after ICU admission, or up to discharge (if occurs before seven days). Patients with previous diagnosis of chronic kidney disease stages IV or V, patients who had used nephrotoxic drugs before the surgery, patients with ICU stay less than 48 hours with diagnosis of sepsis during ICU stay will be excluded. The project was approved by the Ethical Committee of the Hospital das Clínicas da Faculdade de Medicina da USP. Patients have to sign Free Informed Consent before entering the study.