Acute Kidney Injury, Mortality, Length of Stay, and Costs in Hospitalized Patients

Abstract

The marginal effects of acute kidney injury on in-hospital mortality, length of stay (LOS), and costs have not been well described. A consecutive sample of 19,982 adults who were admitted to an urban academic medical center, including 9210 who had two or more serum creatinine (SCr) determinations, was evaluated. The presence and degree of acute kidney injury were assessed using absolute and relative increases from baseline to peak SCr concentration during hospitalization. Large increases in SCr concentration were relatively rare (e.g., >2.0 mg/dl in 105 [1%] patients), whereas more modest increases in SCr were common (e.g., >0.5 mg/dl in 1237 [13%] patients). Modest changes in SCr were significantly associated with mortality, LOS, and costs, even after adjustment for age, gender, admission International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis, severity of illness (diagnosis-related group weight), and chronic kidney disease. For example, an increase in SCr >0.5 mg/dl was associated with a 6.5-fold (95% confidence interval 5.0 to 8.5) increase in the odds of death, a 3.5-d increase in LOS, and nearly $7500 in excess hospital costs. Acute kidney injury is associated with significantly increased mortality, LOS, and costs across a broad spectrum of conditions. Moreover, outcomes are related directly to the severity of acute kidney injury, whether characterized by nominal or percentage changes in serum creatinine. A cute kidney injury (AKI) has been reported in 5 to 7%of hospitalized patients on the basis of several singlecenter reports (1,2). Despite the perception that AKI is relatively common, there is no uniform definition for AKI, and relatively few data regarding its incidence in hospitalized patients are available. Moreover, the relative effects of AKI on mortality, hospital length of stay (LOS), and costs have not been well described. Most studies that have explored downstream effects of AKI have either considered AKI requiring dialysis or homogenous patient populations, such as those who were exposed to radiocontrast agents or undergoing cardiothoracic surgery.In the context of a computer-based intervention in which data were collected on kidney function, severity of illness, drug prescription, and outcomes in hospitalized patients (3), we linked changes in serum creatinine (SCr) with in-hospital mortality, LOS, and costs. We hypothesized that relatively small changes in SCr would be common and associated with adverse outcomes, even after adjustment for severity of disease. Materials and Methods Study SettingThe study was conducted at Brigham and Women's Hospital, a 720-bed urban academic medical center in Boston, MA. Data were obtained for a study to examine the effects of a computer-order entrybased decision tool on drug prescribing for hospitalized patients with impaired kidney function (3). As part of the data library collected for evaluation of the appropriateness of drug prescription, serial SCr determinations were collected on a consecutive series of hospitalized pat...

A multicenter, retrospective study of acute kidney injury in adult patients with nonmyeloablative hematopoietic SCT

“…In a consecutive sample of 19 982 adults admitted to an urban medical center, Chertow et al 11 found that patients with an increase in SCr of just 0.3-0.4 mg per 100 ml had a 70% higher multivariable-adjusted odds of death than did patients with little or no change in SCr. Other investigators have reported similar findings in patients with congestive heart failure.…”

“…[7][8][9] Recently, several investigators have shown that small changes in kidney function in hospitalized patients are important and have an impact on outcome. [10][11][12] Subsequently, the terminology of ARF has been shifted to acute kidney injury (AKI). The Acute Kidney Injury Network (AKIN) criteria provide a uniform definition of AKI and are increasingly used in the literature.…”

Nephrotoxicity Of Polymyxin B: Experimental Study In Cells And Implications For Nursing Practice

“…Clinical features include oliguria or anuria, elevation of serum creatinine and electrolyte disturbances (17) . The incidence of AKI may be associated with periods of prolonged hospitalization resulting in increased morbidity and mortality and, consequently, increase of hospital costs of these patients (18) .…”

Protective effect of indomethacin in renal ischemia-reperfusion injury in mice

“…In native kidneys, IRI is a common cause of acute kidney injury (AKI) in patients who are undergoing cardiac surgery or with critical illness, and it is associated with high mortality and morbidity (Levy et al, 1996;Schiffl et al, 2002;Chertow et al, 2005;Bellomo et al, 2008;Kellum et al, 2008;Kinsey et al, 2008). For decades, non-steroidal antiinflammatory drugs (NSAIDs) have been used successfully in the treatment of numerous clinical diseases for their anti-inflammatory and analgesic effects.…”