Fibrinolytic Capacity and Risk of Bleeding in Intensive Care Patients with Acute Kidney Injury

Acute kidney injury (AKI) is common among intensive care unit (ICU) patients and is associated with increased bleeding risk. The impact of fibrinolysis in AKI-related bleeding has not been explored previously.

(1) Compare fibrinolytic capacity in ICU patients with and without AKI. (2) Investigate the association between fibrinolytic capacity, as well as other laboratory and clinical variables, and bleeding within the first 7 ICU days in AKI patients.

Adult ICU patients were prospectively enrolled and stratified by AKI presence and severity at ICU admission. On the morning after admission, fibrinolytic capacity was assessed using a modified rotational thromboelastometry (ROTEM-tPA) assay. The primary outcome was the difference in ROTEM-tPA lysis time on day 1 of ICU admission between AKI and non-AKI patients.

AKI patients ( n  = 160) had more bleedings and higher 30-day mortality than non-AKI patients ( n  = 99). ROTEM-tPA analysis showed progressively impaired fibrinolysis with increasing AKI severity. AKI stage 3 patients ( n  = 53) demonstrated significant impairment across all fibrinolysis parameters compared with non-AKI patients. Among AKI stage 2 to 3 patients ( n  = 106), bleeding patients ( n  = 61) had more pronounced fibrinolytic impairment than non-bleeding patients ( n  = 45). Bleeding risk in AKI stage 2 to 3 was associated with increasing severity of illness (OR: 1.21 (95%CI 1.04-1.42) per 1 point increase in non-renal Sequential Organ Failure Assessment (SOFA) score, p  = 0.01).

AKI severity in ICU patients was associated with progressively impaired fibrinolysis. Despite this, AKI patients had more bleedings within the first 7 days of ICU admission.