Dataset Information

Association of Oliguria With Acute Kidney Injury Diagnosis, Severity Assessment, and Mortality Among Patients With Critical Illness

ABSTRACT: Key Points

Question

What is the contribution of the oliguria-based Kidney Disease: Improving Global Outcomes (KDIGO) criteria to diagnosis, severity assessment, and outcomes in acute kidney injury (AKI)?

Findings

In this cohort study of 15 620 patients admitted to an intensive care unit, consideration of oliguria-based criteria, in addition to those based on serum creatinine levels alone, enabled identification of AKI or an increase in its severity in 51.7% of critically ill patients. Moreover, oliguria-based stages 2 and 3 AKI appeared to be statistically significantly associated with 90-day mortality after correction for serum creatinine level, comorbidities, and illness severity.

Meaning

These findings suggest that oliguria, as defined by the KDIGO criteria, is associated with mortality in AKI and should be accounted for by clinicians at the bedside and clinical researchers while designing trials. This cohort study examines the association of oliguria with diagnosis, severity assessment, and short- and long-term outcomes of acute kidney injury among patients admitted to an adult intensive care unit.

Importance

The current definition and staging of acute kidney injury (AKI) considers alterations in serum creatinine (sCr) level and urinary output (UO). However, the relevance of oliguria-based criteria is disputed.

Objective

To determine the contribution of oliguria, as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, to AKI diagnosis, severity assessment, and short- and long-term outcomes.

Design, Setting, and Participants

This cohort study included adult patients admitted to a multidisciplinary intensive care unit from January 1, 2010, to June 15, 2020. Patients receiving long-term dialysis and those who declined consent were excluded. Daily sCr level and hourly UO measurements along with sociodemographic characteristics and severity scores were extracted from electronic medical records. Long-term mortality was assessed by cross-referencing the database with the Swiss national death registry. The onset and severity of AKI according to the KDIGO classification was determined using UO and sCr criteria separately, and their agreement was assessed.

Main Outcomes and Measures

Using a multivariable model accounting for baseline characteristics, severity scores, and sCr stages, the association of UO criteria with 90-day mortality was evaluated. Sensitivity analyses were conducted to assess how missing sCr, body weight, and UO values, as well as different sCr baseline definitions and imputations methods, would affect the main results.

Results

Among the 15 620 patients included in the study (10 330 men [66.1%] with a median age of 65 [IQR, 53-75] years, a median Simplified Acute Physiology Score II score of 40.0 [IQR, 30.0-53.0], and a median follow-up of 67.0 [IQR, 34.0-100.0] months), 12 143 (77.7%) fulfilled AKI criteria. Serum creatinine and UO criteria had poor agreement on AKI diagnosis and staging (Cohen weighted κ, 0.36; 95% CI, 0.35-0.37; P < .001). Compared with the isolated use of sCr criteria, consideration of UO criteria enabled identification of AKI in 5630 patients (36.0%). Those patients had a higher 90-day mortality than patients without AKI (724 of 5608 [12.9%] vs 288 of 3462 [8.3%]; P < .001). On multivariable analysis accounting for sCr stage, comorbidities, and illness severity, UO stages 2 and 3 were associated with a higher 90-day mortality (odds ratios, 2.4 [95% CI, 1.6-3.8; P < .001] and 6.2 [95% CI, 3.7-10.5; P < .001], respectively). These results remained significant in all sensitivity analyses.

Conclusions and Relevance

The findings of this cohort study suggest that oliguria lasting more than 12 hours (KDIGO stage 2 or 3) has major AKI diagnostic implications and is associated with outcomes irrespective of sCr elevations.

SUBMITTER: Bianchi N

PROVIDER: S-EPMC8569487 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The cardiorenal syndrome generally focuses on left ventricular function, and the importance of the right ventricle as a determinant of renal function is described less frequently. In a cohort of critically ill patients with echocardiographic measurements obtained within 24 hours of admission to the intensive care unit, we examined the association of right ventricular function with acute kidney injury (AKI) and AKI-associated mortality. We also examined whether clinical measurement of volume overload modified the association between ventricular function and AKI in a subpopulation with documented admission physical examinations.Among 1879 critically ill patients with echocardiographic ventricular measurements, 43% (n = 807) had ventricular dysfunction-21% (n = 388), 9% (n = 167), and 13% (n = 252) with isolated left ventricular dysfunction, isolated right ventricular dysfunction, and biventricular dysfunction, respectively. Overall, ventricular dysfunction was associated with a 43% higher adjusted risk of AKI (95% confidence interval [CI] 1.14-1.80; P = 0.002) compared with those with normal biventricular function, whereas isolated left ventricular dysfunction, isolated right ventricular dysfunction, and biventricular dysfunction were associated with a 1.34 (95% CI 1.00-1.77, P = 0.05), 1.35 (95% CI 0.90-2.10, P = 0.14) and 1.67 (95% CI 1.23-2.31, P = 0.002) higher adjusted risk. Although an episode of AKI was associated with an approximately 2-fold greater risk of hospital mortality in those with isolated left ventricular dysfunction and biventricular dysfunction, in those with isolated right ventricular dysfunction, AKI was associated with a 7.85-fold greater risk of death (95% CI 2.89-21.3, P < 0.001). Independent of ventricular function, peripheral edema was an important determinant of AKI.Like left ventricular function, right ventricular function is an important determinant of AKI and AKI-associated mortality. Volume overload, independently of ventricular function, is a risk factor for AKI. Whether establishment of euvolemia might mitigate AKI risk will require further study.

Project description:Acute kidney injury (AKI) is a frequent complication after living donor liver transplantation (LDLT), and is associated with increased mortality. However, the association between intraoperative oliguria and the risk of AKI remains uncertain for LDLT. We sought to determine the association between intraoperative oliguria alone and oliguria coupled with hemodynamic derangement and the risk of AKI after LDLT. We evaluated the hemodynamic variables, including mean arterial pressure, cardiac index, and mixed venous oxygen saturation (SvO₂). We reviewed 583 adult patients without baseline renal dysfunction and who did not receive hydroxyethyl starch during surgery. AKI was defined using the Kidney Disease Improving Global Outcomes criteria according to the serum creatinine criteria. Multivariable logistic regression analysis was performed with and without oliguria and oliguria coupled with a decrease in SvO₂. The performance was compared with respect to the area under the receiver operating characteristic curve (AUC). Intraoperative oliguria <0.5 and <0.3 mL/kg/h were significantly associated with the risk of AKI; however, their performance in predicting AKI was poor. The AUC of single predictors increased significantly when oliguria was combined with decreased SvO₂ (AUC 0.72; 95% confidence interval (CI) 0.68⁻0.75 vs. AUC of oliguria alone 0.61; 95% CI 0.56⁻0.61; p < 0.0001; vs. AUC of SvO₂ alone 0.66; 95% CI 0.61⁻0.70; p < 0.0001). Addition of oliguria coupled with SvO₂ reduction also increased the AUC of multivariable prediction (AUC 0.87; 95% CI 0.84⁻0.90 vs. AUC with oliguria 0.73; 95% CI 0.69⁻0.77; p < 0.0001; vs. AUC with neither oliguria nor SvO₂ reduction 0.68; 95% CI 0.64⁻0.72; p < 0.0001). Intraoperative oliguria coupled with a decrease in SvO₂ may suggest the risk of AKI after LDLT more reliably than oliguria alone or decrease in SvO₂ alone. Intraoperative oliguria should be interpreted in conjunction with SvO₂ to predict AKI in patients with normal preoperative renal function and who did not receive hydroxyethyl starch during surgery.

Project description:ObjectivesAcute kidney injury frequently complicates critical illness and is associated with high morbidity and mortality. Frailty is common in critical illness survivors, but little is known about the impact of acute kidney injury. We examined the association of acute kidney injury and frailty within a year of hospital discharge in survivors of critical illness.DesignSecondary analysis of a prospective cohort study.SettingMedical/surgical ICU of a U.S. tertiary care medical center.PatientsThree hundred seventeen participants with respiratory failure and/or shock.InterventionsNone.Measurements and main resultsAcute kidney injury was determined using Kidney Disease Improving Global Outcomes stages. Clinical frailty status was determined using the Clinical Frailty Scale at 3 and 12 months following discharge. Covariates included mean ICU Sequential Organ Failure Assessment score and Acute Physiology and Chronic Health Evaluation II score as well as baseline comorbidity (i.e., Charlson Comorbidity Index), kidney function, and Clinical Frailty Scale score. Of 317 patients, 243 (77%) had acute kidney injury and one in four patients with acute kidney injury was frail at baseline. In adjusted models, acute kidney injury stages 1, 2, and 3 were associated with higher frailty scores at 3 months (odds ratio, 1.92; 95% CI, 1.14-3.24; odds ratio, 2.40; 95% CI, 1.31-4.42; and odds ratio, 4.41; 95% CI, 2.20-8.82, respectively). At 12 months, a similar association of acute kidney injury stages 1, 2, and 3 and higher Clinical Frailty Scale score was noted (odds ratio, 1.87; 95% CI, 1.11-3.14; odds ratio, 1.81; 95% CI, 0.94-3.48; and odds ratio, 2.76; 95% CI, 1.34-5.66, respectively). In supplemental and sensitivity analyses, analogous patterns of association were observed.ConclusionsAcute kidney injury in survivors of critical illness predicted worse frailty status 3 and 12 months postdischarge. These findings have important implications on clinical decision making among acute kidney injury survivors and underscore the need to understand the drivers of frailty to improve patient-centered outcomes.

Project description:BACKGROUNDSerum creatinine concentrations (SCrs) are used to determine the presence and severity of acute kidney injury (AKI). SCr is primarily eliminated by glomerular filtration; however, most mechanisms of AKI in critical illness involve kidney proximal tubules, where tubular secretion occurs. Proximal tubular secretory clearance is not currently estimated in the intensive care unit (ICU). Our objective was to estimate the kidney clearance of secretory solutes in critically ill adults.METHODSWe collected matched blood and spot urine samples from 170 ICU patients and from a comparison group of 70 adults with normal kidney function. We measured 7 endogenously produced secretory solutes using liquid chromatography-tandem mass spectrometry. We computed a composite secretion score incorporating all 7 solutes and evaluated associations with 28-day major adverse kidney events (MAKE28), defined as doubling of SCr, dialysis dependence, or death.RESULTSThe urine-to-plasma ratios of 6 of 7 secretory solutes were lower in critically ill patients compared with healthy individuals after adjustment for SCr. The composite secretion score was moderately correlated with SCr and cystatin C (r = -0.51 and r = -0.53, respectively). Each SD higher composite secretion score was associated with a 25% lower risk of MAKE28 (95% CI 9% to 38% lower) independent of severity of illness, SCr, and tubular injury markers. Higher urine-to-plasma ratios of individual secretory solutes isovalerylglycine and tiglylglycine were associated with MAKE28 after accounting for multiple testing.CONCLUSIONAmong critically ill adults, tubular secretory clearance is associated with adverse outcomes, and its measurement could improve assessment of kidney function and dosing of essential ICU medications.FUNDINGGrants from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK/NIH) K23DK116967, the University of Washington Diabetes Research Center P30DK017047, an unrestricted gift to the Kidney Research Institute from the Northwest Kidney Centers, and the Vanderbilt O'Brien Kidney Center (NIDDK 5P30 DK114809-03). The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.

Project description:BackgroundRisk for acute kidney injury (AKI) in older adults has not been evaluated systematically. We sought to delineate the determinants of risk for AKI in older compared with younger adults.Study designRetrospective analysis of patients hospitalized in July 2000 to September 2008.Setting & participantsWe identified all adult patients admitted to an intensive care unit (n=45,655) in a large tertiary-care university hospital system. We excluded patients receiving dialysis or a kidney transplant prior to hospital admission and patients with baseline creatinine levels ≥ 4mg/dL, liver transplantation, indeterminate AKI status, or unknown age, leaving 39,938 patients.PredictorWe collected data for multiple susceptibilities and exposures, including age, sex, race, body mass, comorbid conditions, severity of illness, baseline kidney function, sepsis, and shock.OutcomesWe defined AKI according to KDIGO (Kidney Disease: Improving Global Outcomes) criteria. We examined susceptibilities and exposures across age strata for impact on the development of AKI.MeasurementsWe calculated area under the receiver operating characteristic curve (AUC) for prediction of AKI across age groups.Results25,230 (63.2%) patients were 55 years or older. Overall, 25,120 (62.9%) patients developed AKI (69.2% aged ≥55 years). Examples of risk factors for AKI in the oldest age category (≥75 years) were drugs (vancomycin, aminoglycosides, and nonsteroidal anti-inflammatories), history of hypertension (OR, 1.13; 95% CI, 1.02-1.25), and sepsis (OR, 2.12; 95% CI, 1.68-2.67). Fewer variables remained predictive of AKI as age increased and the model for older patients was less predictive (P<0.001). For the age categories 18 to 54, 55 to 64, 65 to 74, and 75 years or older, AUCs were 0.744 (95% CI, 0.735-0.752), 0.714 (95% CI, 0.702-0.726), 0.706 (95% CI, 0.693-0.718), and 0.673 (95% CI, 0.661-0.685), respectively.LimitationsAnalysis may not apply to non-intensive care unit patients.ConclusionsThe likelihood of developing AKI increases with age; however, the same variables are less predictive for AKI as age increases. Efforts to quantify risk for AKI may be more difficult in older adults.