Inclusion Criteria:  Routine bronchoscopy Patient in perioperative setting Age >=18 years Consent  Exclusion Criteria:  Active or recent (in past 7 days) bleeding in upper airways Recent traumatic injury of the lung associated with (micro-)hemorrhage Blood aspiration Pregnancy Age<18 years Acute kidney injury / Chronic kidney failure / Dialysis Transplantation HIV Hematologic diseases Immunosuppression Anti-Platelet-Therapy