Prognosis for long-term survival and renal recovery in critically ill patients with severe acute renal failure: a population-based study

INTRODUCTION: Severe acute renal failure (sARF) is associated with considerable morbidity, mortality and use of healthcare resources; however, its precise epidemiology and long-term outcomes have not been well described in a non-specified population. METHODS: Population-based surveillance was conducted among all adult residents of the Calgary Health Region (population 1 million) admitted to multidisciplinary and cardiovascular surgical intensive care units between May 1 1999 and April 30 2002. Clinical records were reviewed and outcome at 1 year was assessed. RESULTS: sARF occurred in 240 patients (11.0 per 100,000 population/year). Rates were highest in males and older patients (≥65 years of age). Risk factors for development of sARF included previous heart disease, stroke, pulmonary disease, diabetes mellitus, cancer, connective tissue disease, chronic renal dysfunction, and alcoholism. The annual mortality rate was 7.3 per 100,000 population with rates highest in males and those ≥65 years. The 28-day, 90-day, and 1-year case-fatality rates were 51%, 60%, and 64%, respectively. Increased Charlson co-morbidity index, presence of liver disease, higher APACHE II score, septic shock, and need for continuous renal replacement therapy were independently associated with death at 1 year. Renal recovery occurred in 78% (68/87) of survivors at 1 year. CONCLUSION: sARF is common and males, older patients, and those with underlying medical conditions are at greatest risk. Although the majority of patients with sARF will die, most survivors will become independent from renal replacement therapy within a year

Severe bloodstream infections: A population-based assessment

Objective: Although bloodstream infection commonly results in critical illness, population-based studies of the epidemiology of severe bloodstream infection are lacking. We sought to define the incidence and microbiology of severe bloodstream infection (bloodstream infection associated with intensive care unit admission within 48 hrs) and assess risk factors for acquisition and death. Design: Population-based surveillance cohort. Setting: Multidisciplinary and cardiovascular surgical intensive care units. Patients: All adults with severe bloodstream infection in the Calgary Health Region (population ≈1 million) during 2000-2002. Interventions: None. Measurements and Main Results: Three hundred forty patients had 342 episodes of severe bloodstream infection (15.7 per 100,000 population/year). Several demographic and chronic conditions were significant risk factors for acquiring severe bloodstream infection (relative risk, 95% confidence interval) including age ≥65 yrs (7.0, 5.6-8.7), male gender (1.3, 1.1-1.6), urban residence (2.4, 1.2-5.6), hemodialysis (208.7, 142.9-296.3), diabetes mellitus (5.9, 4.4-7.8), alcoholism (5.6, 3.8-8.0), cancer (7.5, 5.3-10.3), and lung disease (3.8, 2.6-5.4). The most common etiologies were Staphylococcus aureus, Escherichia coli, and Streptococcus pneumoniae (3.0, 3.0, and 1.9 per 100,000/year, respectively). The case-fatality rate was 142 of 340 (42%) for an annual mortality rate of 6.5 per 100,000. Increased Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.1 per point; 95% confidence interval, 1.1-1.2) and presence of a co-morbidity (odds ratio, 2.5; 95% confidence interval, 1.4-4.3) were significant independent predictors of death. Conclusions: Bloodstream infections are commonly severe enough to require management in an intensive care unit and are associated with a high mortality rate. Identification of risk factors for severe bloodstream infection may allow targeting of preventive efforts to individuals at greatest potential benefit.</p

One-Year Mortality in Critically Ill Patients by Severity of Kidney Dysfunction: A Population-Based Assessment

Background: Kidney dysfunction in the intensive care unit (ICU) results in increased morbidity, mortality, and health care costs; however, long-term mortality has not been described across strata of severity in kidney dysfunction. Methods: The primary objective is to describe and assess factors associated with 1-year mortality in critically ill patients stratified by severity of kidney dysfunction during admission to the ICU. Kidney dysfunction is defined by peak serum creatinine values and stratified by: (1) no dysfunction (creatinine < 1.7 mg/dL [<150 μmol/L]), (2) mild dysfunction (creatinine, 1.7 to 3.4 mg/dL [150 to 299 μmol/L]), (3) moderate dysfunction (creatinine ≥ 3.4 mg/dL [≥ 300 μmol/L]), (4) severe acute dysfunction requiring renal replacement therapy (acute renal failure), or (5) preexisting end-stage kidney disease. Population-based surveillance was of adult residents of the Calgary Health Region (population, 1 million) admitted to any multidisciplinary ICU and a cardiovascular surgery ICU from May 1, 1999, to April 30, 2002. Results: Of 5,693 admissions, 62% were men, median age was 64.9 years (interquartile range, 50.6 to 74.5 years), and mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 24.9 ± 8.7 (SD). Case fatality rates stratified by renal dysfunction were 17% (763 of 4,411), 47% (370 of 790), 48% (77 of 160), 64% (153 of 240), and 40% (37 of 92) for no, mild, and moderate dysfunction; severe acute renal failure; and end-stage kidney disease, respectively. By means of multivariate analysis, 1-year mortality was associated independently with advancing age, medical diagnosis, higher APACHE II score, and presence and severity of kidney dysfunction, although no difference was evident comparing those with mild to moderate dysfunction. End-stage kidney disease was not associated independently with 1-year mortality. Conclusion: Severity of kidney dysfunction in patients in the ICU is associated with an incremental increase in long-term mortality. Although patients classified with either mild or moderate kidney dysfunction had an increased risk for death, use of serum creatinine level alone was poor at discriminating long-term outcome, suggesting this measure alone should not be used for defining long-term prognosis.</p