ORIGINAL ARTICLE
Acute Kidney Injury Predicts Outcomes of Non-Critically Ill Patients

https://doi.org/10.4065/84.5.410Get rights and content

OBJECTIVE

To evaluate whether acute kidney injury (AKI), defined as an increase in the serum creatinine level of 0.3 mg/dL or more within 48 hours, predicts outcomes of non-critically ill patients.

PATIENTS AND METHODS

Among the adults admitted from June 1, 2005, to June 30, 2007, to the medical wards of a community teaching hospital, 735 patients with AKI and 5089 controls were identified. Demographic and health information, serum creatinine values, and outcomes were abstracted from patients' computerized medical records. Outcomes of patients with AKI were compared with those of controls. In an additional case-control analysis, more detailed clinical information was abstracted from the medical records of 282 pairs of randomly selected, age-matched AKI cases and controls. Conditional multivariate logistic regression analyses were used to adjust for potential confounders of AKI effect on outcomes.

RESULTS

Overall, patients with AKI had higher in-hospital mortality (14.8% vs 1.5%; P<.001), longer lengths of stay (median 7.9 vs 3.7 days; P<.001), and higher rates of transfer to critical care areas (28.6% vs 4.3%; P<.001); survivors were more likely to be discharged to an extended care facility (43.1% vs 20.3%; P<.001). Conditional multivariate logistic regression analyses of the 282 pairs of cases and controls showed that patients with AKI were 8 times more likely to die in hospital (odds ratio [OR], 7.9; 95% CI [confidence interval], 2.9-15.3) and were 5 times more likely to have prolonged (≥7 days) hospital stays (OR, 5.2; 95% CI, 3.5-7.9) and require intensive care (OR, 4.7; 95% CI, 2.7-8.1), after adjustment for age, comorbidities, and other potential confounders.

CONCLUSION

In this study, AKI was associated with adverse outcomes in non-critically ill patients.

Section snippets

PATIENTS AND METHODS

This combined retrospective cohort and case-control study was conducted after approval by the institutional review board of Bridgeport Hospital, a 350-bed community teaching hospital affiliated with the Yale New Haven Health System. All adults admitted to the hospital medical wards from June 1, 2005, to June 30, 2007, were potentially eligible for inclusion. Patients were excluded if they had less than 2 creatinine measurements during their hospital stay, had undergone RRT in the 12 weeks

Characteristics and Outcomes of the Overall Cohort

Of the 16,039 patients admitted to medical wards during the study period, the following were excluded: 5406 patients for whom this was not a first admission, 128 patients who received RRT before admission or within the first 48 hours of hospitalization, 1968 patients who were initially admitted to the ICU, and 2504 patients who had no or only 1 creatinine measurement. Of the 6033 remaining eligible patients, 209 (3.5%) were excluded who had increases in serum creatinine level of 0.3 mg/dL or

DISCUSSION

This study confirms that AKI, defined as an increase in serum creatinine level of 0.3 mg/dL or more within 48 hours, predicts clinical outcomes of non-critically ill patients. Acute kidney injury was associated with a nearly 7-fold (adjusted OR, 7.9; 95% CI, 2.9-15.3) increased odds of death, a more than 4-fold increased odds of prolonged (≥7 days) LOS, and a nearly 4-fold increased odds of transfer to critical care units. These findings are consistent with our findings in a cohort of

CONCLUSION

An abbreviated definition of AKI (ie, an increase in serum creatinine level of 0.3 mg/dL or more within 48 hours) is associated with adverse clinical outcomes, including in-hospital mortality, prolonged hospital LOS, need for intensive care, and discharge to an ECF. If our findings can be replicated at other centers, then the Acute Kidney Injury Network criteria for AKI provide a simple, scientifically valid definition that could foster research in this field.

Acknowledgments

The authors are grateful to Ryan O'Connell, MD, for his assistance coordinating with hospital informatics and Ms. Joan Huff for data acquisition from hospital information systems.

REFERENCES (25)

  • EA Hoste et al.

    Acute kidney injury: epidemiology and diagnostic criteria

    Curr Opin Crit Care

    (2006)
  • RL Mehta et al.

    Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

    Crit Care

    (2007)

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    Drs Barrantes and Feng contributed equally to first authorship.

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    Copyright © 2009 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.