A Multicentre, Double-blind, Randomized Controlled Trial of Inhaled Amikacin Versus Placebo in Critically Ill Patients With Ventilator-associated Tracheobronchitis

VAT will be defined using the following criteria: (i) duration of mechanical ventilation > 48 hours, (ii) purulent tracheobronchial secretions, (iii) no new or progressive persistent pulmonary infiltrate on chest X-ray, and (iv) bacterial growth on endotracheal aspirate (ETA) ≥10.5 colony-forming unit (CFU)/mL or on bronchoalveolar lavage ≥10.4 CFU/mL or on plugging telescopic catheter ≥10.3 CFU/mL. Inclusion and randomization will be performed after written informed consent, as soon as inclusion criteria are met, within 24 hours after VAT suspicion (ETA sampling) whenever possible. Patients in the experimental group will receive inhaled amikacin (once daily, 20 mg/kg of predicted body weight with a maximum of 2 grams) from Day 1 (inclusion, randomization and first nebulization) to Day 5 through an optimized and protocolized nebulization procedure (vibrating mesh nebulizer). Patients in the control group will receive inhaled placebo (NaCl 0.9%, once daily) from Day 1 (inclusion, randomization and first nebulization) to Day 5 through an optimized and protocolized nebulization procedure (vibrating mesh nebulizer). Nebulization will be performed according to a standardized procedure using a vibrating mesh nebulizer (Aerogen Solo, Aerogen, Galway, Ireland). A bedside checklist will be used to ensure optimal implementation practice. All staff involved in nebulization will be trained prior to their study involvement. The systemic diffusion and pharmacokinetics of inhaled amikacin will be assessed through measurement of peak and residual blood concentrations in a pre-planned subsample of patients. Study treatment will be discontinued before the 5th administration in the following cases: (i) documented acquired amikacin resistance in at least one pathogen responsible for VAT, (ii) occurrence of VAP before Day 5, (iii) occurrence of AKI stage 2 or 3 of the KDIGO classification before Day 5 (except for patients receiving renal replacement therapy), (iv) clinical indication for mandatory IV aminoglycoside therapy (amikacin, gentamicin, tobramycin) before Day 5, (v) extubation before Day 5, (vi) unexpected SAE deemed related to the IP and/or a patient's clinical condition that requires suspension of the treatment according to the local investigator. Patients will be followed-up until Day 28 for the primary study endpoint and up to Day 90 for certain secondary study endpoints (Day-90 mortality, and day-90 health-related quality of life [HRQoL] in survivors).