A real-world prospective study on dialysis-requiring acute kidney injury

Abstract

Background Current information about acute kidney injury (AKI) epidemiology in developing nations derives mainly from isolated centers, with few quality multicentric epidemiological studies. Our objective was to describe a large cohort of patients with dialysis-requiring AKI derived from ordinary clinical practice within a large metropolitan area of an emerging country, assessing the impact of age and several clinical predictors on patient survival across the spectrum of human life. Methods We analyzed registries drawn from 170 hospitals and medical facilities in Rio de Janeiro, Brazil, in an eleven-year period (2002–2012). The study cohort was comprised of 17,158 pediatric and adult patients. Data were analyzed through hierarchical logistic regression models and mixed-effects Cox regression for survival comparison across age strata. Results Severe AKI was mainly hospital-acquired (72.6%), occurred predominantly in the intensive care unit (ICU) (84.9%), and was associated with multiple organ failure (median SOFA score, 11; IQR, 6–13). The median age was 75 years (IQR, 59–83; range, 0–106 years). Community-acquired pneumonia was the most frequent admission diagnosis (23.8%), and sepsis was the overwhelming precipitating cause (72.1%). Mortality was 71.6% and was higher at the age extremes. Poor outcomes were driven by age, mechanical ventilation, vasopressor support, liver dysfunction, type 1 cardiorenal syndrome, the number of failing organs, sepsis at admission, later sepsis, the Charlson score, and ICU admission. Community-acquired AKI, male gender, and pre-existing chronic kidney disease were associated with better outcomes. Conclusions Our study adds robust information about the real-world epidemiology of dialysis-requiring AKI with considerable clinical detail. AKI is a heterogeneous syndrome with variable clinical presentations and outcomes, including differences in the age of presentation, comorbidities, frailty state, precipitation causes, and associated diseases. In the cohort studied, AKI characteristics bore more similarities to upper-income countries as opposed to the pattern traditionally associated with resource-limited economies.

Socioeconomic Influences on the Outcomes of Dialysis-Requiring Acute Kidney Injury in Brazil

“… 27 Furthermore, it was not our intention to produce a population-level analysis regarding the incidence and prevalence of AKI-D. As stated, the institutions involved do not represent the whole scope of Rio de Janeiro’s medical facilities, as can be gathered by the higher prevalence of private hospitals in the cohort. 15 It is also important to note that the hospitals studied in the manuscript were unequally distributed in the city of Rio de Janeiro, showing higher concentrations in neighborhoods with higher human development index and not according to population distribution. This uneven distribution of hospitals may be indicative of existing inequities in the accessibility and availability of healthcare services within the city, which could impact the generalizability of our findings.…”

“…Our previous publications with the same cohort showed a significant association between preexisting CKD and these adverse kidney outcomes. 15 The higher median age of the cohort may partly explain these findings. However, we acknowledge that the lack of long-term follow-up of the patients may have affected our analysis of kidney recovery outcomes.…”

“…We performed a retrospective analysis of the NefroWeb database, an 11 year (2002–2012) prospective, multicenter study on clinical characteristics and outcomes of AKI-D in the metropolitan area of Rio de Janeiro, Brazil. 15 The study included 170 private and public hospitals and medical institutions. Personally sponsored or company-sponsored private health plans or insurance (market oriented) were the primary source of funding in private governance hospitals.…”

“…After nephrology consultation and AKI-D diagnosis, data were entered into the clinical module of NefroWeb, a customized Microsoft SQL Server database, by the attending nephrologist at the time of renal replacement therapy (RRT) initiation. 15 Because the study was noninterventional, the institutional research ethics board approved the study protocol and waived the need for informed consent. This paper follows the STROBE guidelines for cohort studies ( Supplementary File S1 , Appendix )…”

“…The study protocol was previously described in detail. 15 Briefly, we collected patient demographic data (age, sex, and race) and clinical variables (primary clinical or surgical diagnosis, renal diagnosis, and comorbidities [the Charlson comorbidity score was derived from the database's extensive list of comorbidities and clinical diagnoses available in the database], precipitant cause of AKI-D, and severity of presentation and organ failures), AKI-D phenotype (e.g., de novo AKI vs. acute-on-chronic kidney disease [ACKD] and hospital-acquired vs. community-acquired AKI), dialysis indication, and modality at the time of dialysis initiation. By conducting detailed medical histories and laboratory studies at enrollment, we identified and excluded patients with CKD who were beginning dialysis at the time of hospital admission.…”