Incidence, Risk Factors, and Prognosis of Gastrointestinal Hemorrhage Complicating Acute Renal Failure

Background: Few prospective data are currently available on acute gastrointestinal hemorrhage (AGIH) as a complication of acute renal failure (ARF). The aim of the present study was to define incidence, sources, risk factors, and outcome of AGIH in patients with ARF.

Methods: We performed a prospective study on an inception cohort of 514 patients admitted for ARF to a nephrology intermediate care unit. Data on clinical risk factors for bleeding, frequency of occurrence of AGIH, length of hospital stay, and in-hospital mortality were collected. Independent predictors of AGIH were identified. The relative odds of death and the relative increase in length of hospital stay associated with AGIH were calculated after adjusting for baseline comorbidities.

Results: Sixty-nine patients out of 514 [13.4% (95% CI, 10.6 to 16.7)] had AGIH as a complication of ARF; 59 were upper AGIH. Forty patients had clinically important bleeding. Erosions and/or ulcers accounted for 71% of cases of upper AGIH. Independent baseline predictors of AGIH were represented by severity of illness [odds ratio 1.45 (95% CI, 1.05 to 2.01) for every 10 point increase in APACHE II score], low platelet count [<50,000 mm3; 3.71 (1.70 to 8.11)], noncirrhotic chronic hepatic disease [2.22 (1.09 to 4.55)], liver cirrhosis [3.38 (1.50 to 7.60)], de novo ARF [2.77 (1.30 to 5.90)], and severe ARF [2.07 (1.10 to 3.88)]. In-hospital mortality was 63.8% in patients with AGIH and 34.2% in the other patients; after adjusting for baseline confounders, AGIH remained significantly associated with an increase in both mortality [2.57 (1.30 to 5.09), P = 0.006] and length of hospital stay [37% (1 to 87%), P = 0.047].

Conclusions: AGIH and clinically important bleeding are frequent complications of ARF. In this clinical condition, AGIH is more often due to upper gastrointestinal bleeding and is associated with a significantly increased risk of death and length of hospital stay. Both renal and extrarenal risk factors are related to the occurrence of AGIH.