SAFETY OF BRONCHOALVEOLAR LAVAGE IN HEMATOLOGICAL PATIENTS WITH THROMBOCYTOPENIA – A RETROSPECTIVE COHORT STUDY

Background Hospitalized hematological patients often require bronchoalveolar lavage (BAL). Paucity of evidence exists as to the potential risks in patients with very-severe thrombocytopenia (VST). Methods This retrospective-cohort study included adult hematological in-patients with VST, defined as platelets<20x103/μL, undergoing BAL during 2012-2021. Mechanically-ventilated patients or those with known active bleeding were excluded. Primary outcomes included major bleeding halting the BAL or deemed significant by the treating physician, need for any respiratory support other than low flow O2 or death within 24 hours. Any other bleeding were recorded as secondary outcomes.    Results Of the 507 patients included in the final analysis, the 281 patients with VST had lower hemoglobin (Md=0.3, p=0.003), longer prothrombin-time (Md=0.7s, p=0.025), higher chances of preprocedural platelet transfusion (RR 3.68, 95%CI[2.86,4.73]), and only one primary-outcome event (death of septic shock 21h postprocedurally) - compared with 3 (1.3%) events (two bleedings halting procedure and one need for non-invasive-ventilation) in patients with platelets ≥20x103/μL (p=0.219). Risk of minor, spontaneously resolved bleeding was higher (RR=3.217, 95%CI[0.919,11.262]) in patients with VST (4.3% vs 1.3%, p=0.051). No association was found between any of the complications recorded and preprocedural platelets, age, aPTT, PT, hematological status, or platelet transfusion.  Conclusions This data suggests BAL to be safe even when platelet counts are <20x103/μL