RASECAL-Bronchoscopic Ambusampler

Inclusion Criteria: (All are required) * Clinicians experienced in performing bronchoscopies (i.e. bronchoscopists should have performed a minimum 5 bronchoscopies in mechanically ventilated patients and a minimum of 5 bronchoscopies in a simulated or practice setting). * Clinicians who have undergone the online product-training module for the use of the Ambu Bronchosampler, with self-certification documented. * Clinicians who have simulated the online product training module using an Ambu Bronchosampler and Ambu Ascope4 a minimum of 5 times in a practice setting and have self-certified. Population * Patients ≥ 18 years old * Patients on mechanical ventilation with Acute respiratory failure for \>4h * Patients eligible for a clinically indicated bronchoscopy with fluid sampling. Patient information has been explained and verbal or written consent has been obtained Exclusion Criteria: Investigators * Investigators who have not completed product training in aScope BronchoSampler by online and hands-on from Ambu product specialists or an experienced user from the site. * Investigators with experience in \< 5 self-verified simulated fluid sampling procedures using the Ambu BronchoSampler 4.8.2 Population * Clinician concern regarding safety of bronchoscopy * Involved study personal not available to perform the procedure and enroll the patient