Intensive versus Standard Care for In-Hospital AKI

Among hospitalized patients, the incidence of acute kidney injury (AKI) ranges from 4% to 21%, making AKI one of the most common and cost-intensive acute diseases in hospitalized patients. Patients with AKI frequently develop chronic renal failure or terminal renal failure. In Germany, the estimated prevalence of chronic renal failure is 2 million individuals.

Cardiorenal complications that include death, chronic dialysis, decline in renal function, heart failure, and stroke occur more frequently following AKI than after myocardial infarction. Undetected AKI (delayed treatment) is an independent risk factor for in-hospital mortality. Specialist medical societies are recommending urgent multimodal treatment for AKI that includes prompt detection of triggering factors and complications that indicate the need to consult expert advice on treatment. According to researchers in Germany, specialized treatment for AKI, initiated in response to an early-warning system, may be beneficial compared  with routine treatment.

The research team, led by Anja Haase-Fielitz, PharmD, and Saban Elitok, MD, conducted an explorative randomized controlled study to explore the variability of effect estimates and feasibility indicators of intensified treatment compared with routine care. Results were reported in Deutsches Ärzteblatt International [2020;117:289-296].

Patients with AKI in regular wards of a university hospital were treated either with routine care (control group) or with intensive treatment (intervention group). Patients were randomly assigned to one of the two groups. The more intensive treatment included an early warning system for a rise in serum creatinine concentration, immediate specialist consultation, and the issuance of a patient kidney passport.

The primary end point of interest was recovery of renal function after AKI during the index hospitalization. Recovery of renal function was defined as the proportion of patients who regained baseline renal function, or as the change in estimated glomerular filtration rate (eGFR) between admission and discharge during the index hospital stay. Attainment of baseline renal function was defined as an increase in eGFR to at least 90% of baseline by the time of hospital discharge. Secondary end points were renal complications and process indicators of clinical care and the time requirements of the study.

A total of 96 patients with AKI identified by the AKI early warning system were evaluated for study inclusion. Of those, 44 were excluded due to inability to consent (n=25), being treated in a nephrology or intensive care unit (n=9), participation in another study (n=3), other reasons and decline to participate (n=7). The remaining 52 patients were randomized to either the intervention group (n=26) or routine treatment (n=26). All 52 were included in the intention-to-treat analysis. The study groups were similar in demographic characteristics, comorbidities, admitting specialist department, status on admission, renal function at time of admission, AKI stage, and range of triggering factors.

Fifty percent of the patients in the intervention group and 42% of those in the control group regained baseline renal function (odds ratio with control group as reference: 1.14; 95% confidence interval, 0.5-4.0; P=.58). From admission to discharge, eGFR fell by 3 mL/min/1.73 m² in the intervention group and by 13 mL/min/1.73 m² in the control group (P=.09). Complications associated with AKI, including hyperkalemia, pulmonary edema, and renal acidosis, occurred less frequently in the intervention group than in the control group (15% vs 39%, respectively; P=.03); the difference was due primarily to higher incidence of hyperkalemia in the control group.

Patients in the intervention group received prompt specialist consultation more frequently than those in the control group (65% vs 4%; P<.001). In the intervention group, mean time of consultation was the day of AKI onset, compared with 2 days following AKI onset in the control group (P=.003).

The cause of AKI was more frequently identified in the intervention group compared with the control group (27% vs 4%; P=.05). In the intervention group, compared with the control group, drugs related to the kidney were discontinued more frequently (65% vs 31%; P=.01), and the diagnosis of AKI was more frequently documented in the patient’s chart (58% vs 37%; P=.03). Triggering factors for AKI were undocumented and untreated less often in the intervention group compared with the control group (4% vs 27%; P=.05).

The researchers cited the explorative design of the study and the small sample size as limitations to the findings.

In conclusion, the researchers said, “Within the constraints of the study limitations, the results of this explorative randomized investigation describe the feasibility and effects of specialist-supported AKI early warning systems on regular units. Studies with sufficient power are needed to demonstrate proof of efficacy for intensified treatment.”

Takeaway Points

1. Researchers in Germany conducted an explorative randomized controlled study to examine the efficacy of intensive treatment initiated in response to an early warning system of patients with AKI in a regular hospital ward.
2. In the intervention group, 50% of patients with AKI recovered renal function, compared with 42% of those in the group that received standard care (control group), and complications were rarer in the intervention group compared with the control group (15% vs 39%; P=.03).
3. In the intervention group, estimated glomerular filtration rate decreased from hospital admission to discharge by 3 mL/min/1.73 m² compared with 13 mL/min/1.73 m² in the control group.