This is a single centre, open-label, feasibility randomised controlled trial. The study aims to assess the feasibility of conducting an RCT to compare the PneuX ETT with standard care in hospitalised patients requiring mechanical ventilation. The patient population for this study are those who are experiencing critical illness requiring intubation and ventilatory support. Patients will be randomised in equal proportions into one of 2 arms: to be intubated using a Venner PneuX Endotracheal Tube (ETT) or using the standard tube. For this feasibility study, a total of 50 patients will be randomised into two groups (25 in each). All patients will be recruited at a single site (University Hospital of Wales, part of Cardiff \& Vale UHB). The study will investigate several feasibility measures including recruitment, delivery of the intervention (including device-related adverse events), acceptability and adherence to the intervention and sampling, use of Peptest to measure microaspiration events, rate of pepsin positive samples, rate of tracheobronchial colonisation, volume of sub-glottic aspirate, rate of VAP, length of ICU and hospital stay, demonstrate the validity of study documentation and provide preliminary data for 50 patients. The data will inform the pilot and main phase of the study.