Title: Choosing the right tracheostomy tube for patients in the intensive care unit: size matters
Funder: Health Education England

Abstract: Research Question: What factors should be considered when selecting the size of tracheostomy tube (TT) for adult patients in ICU? Background: Tracheostomy is an increasingly common procedure on ICU. It is commonly used where dependency on mechanical ventilation (MV) is prolonged, to facilitate weaning from MV, and where the airway is threatened, compromised or dysfunctional. The size of TT is important. A tube should be large enough to facilitate delivery of MV, long enough to remain safely within the trachea, but not so large as to cause damage to the windpipe (trachea). Larger tubes can prevent the restoration of speech and cause long-term damage. The loss of speech can have a significant emotional and psychological impact on patients as well as affecting treatment decisions. There are currently no guidelines detailing how to select the size of TT. Aims and Objectives: Primary aim: to provide practical guidance on factors to consider when selecting the size of TT for adult patients in ICU that takes into account i) anatomical, physiological and physical properties of the trachea and TTs, and ii) patients' priorities in terms of physical and psychological outcomes. Secondary aim: to propose strategies to support implementation of recommendations by clinicians involved in the insertion of TTs and decisions relating to the management of TTs, e.g. ICU and ENT Consultants, speech and language therapists, physiotherapists and nurses. Methods: A multiphase mixed methods project comprising of: 1. a metasynthesis of the literature on patient experience of having a tracheostomy that will reveal the tracheostomy related outcomes that are most important to patients; 2. an observational cohort workstream to test a hypothesis relating to correlations between tracheal diameter and biometrics that can be easily measured at bedside; 3. a bench top workstream investigating resistance to airflow through and around a TT to determine the sizes of tracheostomy that can meet requirements for MV and speech, and 4. a qualitative workstream that uses focus groups of different healthcare professionals involved in the insertion and management of TTs, to feedback findings and identify potential barriers to change in practice. Timelines for delivery: The project will take 42 months to complete. Anticipated impact and dissemination: development of the world's first evidence-based guidance for the selection of TT size at time of insertion, enabling clinicians to make decisions based on achieving important physical and psychological patient outcomes. Dissemination will be via professional networks, conferences, peer reviewed publication, plain English summaries for patient groups and social media.

Lay abstract: Aims:The main aim of this research is to create guidance for Health Care Professionals (HCPs) on how to select the right size tracheostomy tube (TT) for patients in an intensive care unit (ICU). The second aim is to identify ways to best ensure that HCPs follow the guidance. Background:Some patients on ICU need a machine to help them breathe (mechanical ventilation, MV). If they need MV for more than two weeks, guidance is that doctors should insert a plastic tube via a small incision at the front of the neck. This tube is called a tracheostomy tube (TT). In the long term this is more comfortable and safer than having a breathing tube via the mouth. Many patients with TTs can use a one-way speaking valve (SV) that redirects air over the vocal folds, to help them to talk. Selecting the right size TT is important. A poorly fitting TT can cause harm to patients and increase costs to the NHS. For a MV patient the TT must be big enough to breathe through it easily. It must also be small enough for air to pass around it when the patient wants to talk, or to be able to use a SV. Not being able to talk can be incredibly distressing for patients on ICU (1). It can also prevent them expressing choices about their treatment. SVs have other benefits for patients. They can help patients move towards breathing for themselves again and the removal (weaning) of the TT (2). They can also help patients swallow food and drink more safely. TTs that are too large or too small are likely to sit in the wrong position in the windpipe (trachea). This can cause scarring and long-term narrowing of the trachea. If the narrowing is severe, the patient may need surgery to correct it (3). There is currently no detailed guidance on how to select the best size tube for patients on ICU. Design and Methods:This research consists of four separate but linked workstreams. I will first look at what matters most to patients when it comes to having a TT. I will do this by looking at existing research into patients' experiences of having a TT. I will summarise the information and identify common themes. Secondly, I will investigate information that HCPs can get at the bedside to give an idea of the size of a patient's trachea. I will measure the trachea of outpatient volunteers. I will then compare measurements to the patients' height, shoulder width, age and sex. Thirdly, I will use hi-tech models of the trachea and lungs to find what sizes will allow patients to breathe through and around the TT comfortably. Lastly, I will present the findings of workstreams 1-3 to HCPs and ask for their feedback. I will also look for possible barriers and enablers for changing practice. Patient and Public Involvement:Feedback from patients and families indicated that this research is necessary. They reported that being able to talk and wean quickly from MV and the TT was important to them. I will involve patients and the public throughout the research project, e.g. I will ask for help in recruiting people for the workstream involving tracheal measurement, in analysing results of each workstream and for ideas about sharing the findings. Dissemination:I will share results of the project through patient forums and support groups. I will share results with HCPs through their professional networks, at conferences, in scientific journals and on the National Tracheostomy Safety Project website.

Research activity codes: 6.3 MEDICAL DEVICES;6.4 SURGERY
Health categories: GENERIC HEALTH RELEVANCE