Can noble metal coating reduce the incidence of ventilator associated pneumonia (VAP): A multicenter double blind randomized pilot study

Introduction: Ventilator associated pneumonia is still a problem in the intensive care unit (ICU) Noble metal coating of endotracheal tubes reduces the adhesion of bacteria and could reduce the incidence of VAP Methods: A controlled prospective randomized, double blind, multicenter study was launched in November 2018 in Liege, Belgium enrolling 324 patients from 8 ICUs from 4 sites of two hospital institutions using endotracheal tubes for ventilated patients from Bactiguard These tubes with subglottic suctioning had, for half of them, a thin coating of noble metals (gold, silver and palladium) firmly attached to their surfaces, preventing bacteria from adhering and forming biofilm Coated tubes were indistinguishable from control tubes Coated and control tubes were coded and remained blinded for all the participants Patients were followed during ventilation and ICU stay up to 28 days Tracheal colonization, incidence of VAP, and antibiotic consumption were recorded Results: The study ended on 5 March 2020 before the Covid-19 pandemic occurrence in Liege Data are given as a whole because the code is not yet broken This will be done before the European convention Among the 324 patients with a median age of 67 5 (IQR 56,5- 74,6), there were 179 men (55 4%) Their mean Charlson score was 2 (IQR 1-4) and the mean saps II score, calculated the day of intubation, was 50 5 ± 17 5 The median length of ventilation through both uncoated and coatedtubes was 5 days (IQR 3-9) totaling 2202 ventilatory days No bacteria were found in tracheal sputum from 122 patients during ventilation Persistence of bacteria already present in tracheal sputum the day of intubation was documented in 38 patients and new bacteria were found in 76 patients No sampling was done in 88 patients, partially because of too short ventilation (n = 26) During ventilation and 2 days after extubation, there were 55 suspected episodes of VAP The analysis of these episodes based on the presence of new infiltrate on X-ray exam, fever, leucocytosis, increase of the FiO2 or Peep level, quantitative bacteriological result and CRP change, leads to reject 25 suspicions and classifies the 30 other as confirmed (n = 2), probable (n = 12) or possible (n = 16) The overall incidence of VAP was 13 7/1000 ventilatory days or 9 3/100 patients Antibiotic from any kind was used during 68 7 % of ventilatory days and 61 7% of ICU days ICU mortality was 41 9 % and hospital mortality was 50 8% Conclusion: This is the first report of a randomized double blind study with Bactiguard tubes which will allow to define the number of patients for a confirmatory larger study