Tolerability and performance of BIP endotracheal tubes with noble metal alloy coating – a randomized clinical evaluation study

Gunilla Björling, Dorota Johansson, Linda Bergström, Shah Jalal, Ivar Kohn, Claes Frostell, Sigridur Kalman

Hospital acquired infections worsen the outcome of patients treated in intensive care units and are costly. Coatings with silver or metal alloys may reduce or alter the formation of biofilm on invasive medical devices. An endotracheal tube (ETT) is used to connect the patient to a ventilator and coated tubes have been tested in relation to bacterial colonization and respiratory infection. In the present study, we aimed to evaluate and compare a coated and uncoated ETT for patient symptoms and local tracheal tolerability during short term clinical use. Degree of bacterial colonization was also described. A silver-palladium-gold alloy coating ('Bactiguard®'Infection Protection, BIP) has been extensively used on urinary tract catheters and lately also on central venous catheters. We performed a randomised, single-blinded, controlled, first in man, post Conformité Européenne (EC) certification and CE marking study, focused on Bactiguard® coated ETTs (BIP ETT). Thirty patients at a tertiary university hospital scheduled for upper abdominal elective surgery with an expected duration of anaesthesia of at least 3 h were randomised; BIP ETT (n = 20) or standard ETT (n = 10). The tolerability was assessed with a modified version of Quality of Life Head and Neck Module, QLQ-H&N35 and by inspection of the tracheal mucosa with a fibre-optic bronchoscope before intubation and at extubation. Adverse Events (AE) and bacterial adherence were also studied. Statistical evaluations were carried out with the Fisher's Exact Test, the Clopper-Pearson method, as well as a Proportional Odds Model. Differences between groups were identified in 2 of 8 patient related symptoms with regard to tolerability by QLQ-H&N35 (cough, p = 0.022 and dry mouth, p = 0.014 in the treatment group.). No mucosal damage was identified with bronchoscopy. A low level of bacterial colonization with normal flora, equal between groups, was seen after short-term of intubation (median 5 h). No serious Adverse Events related to the use of an ETT were observed. The results should be treated with caution due to statistical confounders, a small study size and large inter-individual variability in bacterial adhesion. The new device BIP ETT is well tolerated and has good clinical performance during short-term intubation. Studies with larger sample sizes and longer intubation periods (>24 h) in the ICU-setting are needed and can now be planned in order to identify possible differences in clinical outcomes. Registered in ClinicalTrials.gov, NCT01682486 , Date of Registration: August, 30, 2012.