Severe bleeding events among critically ill patients with haematological malignancies

Background Bleeding events are common complications in critically ill patients with haematological malignancies. The objective of this study was to assess the incidence and identify determinants of ICU-acquired severe bleeding events in critically ill patients with haematological malignancies. We conducted a single-center retrospective study including all adult patients with a history of haematological malignancy requiring unplanned ICU admission over a 12-year period (2007-2018). The primary endpoint was the occurrence of ICU-acquired (i.e. after the first 24 h in the ICU) severe bleeding events, as defined as grades 3 or 4 of the World Health Organization classification. Results A total of 1012 patients were analysed, mainly with a diagnosis of lymphoma (n = 434, 42.9%) and leukaemia or myelodysplastic syndrome (n = 266, 26.3%). Most patients were recently diagnosed (n = 340, 33.6%) and under active cancer treatment within the last 3 months (n = 604, 59.7%). The main cause for admission was infection (n = 479, 47.3%), but a significant proportion of patients were admitted for a primary haemorrhage (n = 99, 10%). ICU-acquired severe bleeding events occurred in 109 (10.8%) patients after 3.0 days [1.0-7.0] in the ICU. The main source of bleeding was the gastrointestinal tract (n = 44, 40.3%). Patients experiencing an ICU-acquired severe bleeding event displayed prolonged in-ICU length of stay (9.0 days [1.0-6.0] vs. 3.0 [3.5-15.0] in non-bleeding patients, p < 0.001) and worsened outcomes with increased in-ICU and in-hospital mortality rates (55% vs. 18.3% and 65.7% vs. 33.1%, respectively, p < 0.001). In multivariate analysis, independent predictors of ICU-acquired severe bleeding events were chronic kidney disease (cause-specific hazard 2.00 [1.19-3.31], p = 0.008), a primary bleeding event present at the time of ICU admission (CSH 4.17 [2.71-6.43], p < 0.001), non-platelet SOFA score (CSH per point increase 1.06 [1.01-1.11], p = 0.02) and prolonged prothrombin time (CSH per 5-percent increase 0.90 [0.85-0.96], p = 0.001) on the day prior to the event of interest. Conclusions Major bleeding events are common complications in critically ill patients with haematological malignancies and are associated with a worsened prognosis. We identified relevant risk factors of bleeding which may prompt closer monitoring or preventive measures.