Outcomes of cancer patients admitted to intensive care units with severe acute kidney injury

Introduction

Critically ill cancer patients are at increased risk for acute kidney injury (AKI), but studies on these patients are scarce and were all single centered, conducted in specialized ICUs. The aim of this study was to evaluate the characteristics and outcomes in a prospective cohort of ICU cancer patients with AKI.

Methods

Prospective multicenter cohort study conducted in ICUs from 28 hospitals in Brazil over a 2-month period. Univariate and multivariate logistic regression were used to identify factors associated with hospital mortality.

Results

Out of all 717 ICU admissions, 87 (12%) had AKI and 36% of them received dialysis. Kidney injury developed more frequently in patients with hematological malignancies than in patients with solid tumors (26% vs 11%, P = 0.003). Ischemia/shock (76%) and sepsis (67%) were the main contributing factors, and kidney injury was multifactorial in 79% of the patients. The ICU mortality was 61% (53/87) and hospital mortality was 71% (62/87). Despite the lack of statistical significance, hospital mortality was higher in patients who received RRT later on during the ICU stay (92%) in comparison with those who received RRT on the first day in the ICU (78%) and those who were not dialyzed (64%) (P = 0.105). End-of-life decisions (to withhold or to withstand therapies) were taken in 18 (23%) patients. General and renal-specific severity-of-illness scores were inaccurate in predicting outcomes for these patients. In a multivariate analysis, length of hospital stay prior to ICU, acute organ dysfunctions, need for mechanical ventilation and a poor performance status were associated with increased mortality. Moreover, cancer-related characteristics were not associated with outcomes.

Conclusions

The present multicenter study confirmed that AKI in critically ill patients with cancer is frequent, usually multifactorial and still associated with high mortality rates. On the other hand, the current study also suggests that ICU admission and RRT should be considered in selected patients. Mortality in these patients is mostly dependent on the severity of acute illness and the performance status, rather than cancer-related characteristics.