The Safety and Efficacy of One-Way Speaking Valves

Abstract

Patients with tracheostomies consume a lot of healthcare resources. These patients are amongst the most critically ill, they have longer lengths of stay, higher rates of morbidity and mortality, and for those that do survive, they can take up more Intensive Care Unit bed days than patients without tracheostomies. Tracheostomies also affect a number of physiological functions, including swallowing, olfaction, and secretion management. But probably what is most significant to patients, is that the presence of a tracheostomy inhibits speech, as air no longer passes through the larynx and across the vocal cords. For decades patients with tracheostomies were unable to communicate, resulting in frustration, anxiety, and reduced quality of life. That was until the Passy-Muir Valve was created in 1985, allowing patients with tracheostomies to speak. The Passy-Muir Valve is a simple one-way valve that redirects airflow past the vocal cords, to enable speech when the tracheostomy cuff is deflated. Due to this simple unique design, it has been proposed that there may be a number of other benefits to these valves, ranging from reducing aspiration, to improving quality of life. With any novel therapy that is introduced to patients, there needs to be adequate evidence to support the use, as well as identifying risks which may put patients at harm. The evidence around the use of Passy-Muir Valve for benefits other than speech, has not yet been evaluated. The aims of this thesis are to review the literature for use of one-way speaking valves, and to evaluate the evidence for the use across all physiological domains. A systematic review was completed, evaluating the evidence for a range of physiological outcomes, including vital signs, aspiration, olfaction, ventilation, tracheostomy weaning, length of stay and quality of life. A meta-analysis random-effect model (I2 =71.76, p = 0.006) found reduced instances of aspiration with the use of a one-way speaking valve, compared to without. There were also statistically significant improvements across other physiological domains, including olfaction, secretion management, and ventilation. For the remaining outcomes, the use of a one-way speaking valve demonstrated improvements that were not statistically significant, and no study demonstrated negative outcomes. Unfortunately, safety and adverse events were not well defined in any of the studies. Subsequently, an observational study was completed to evaluate the effect on cardiorespiratory parameters, including heart rate, respiratory rate, blood pressure and saturations of oxygen, in terms of safety and physiological efficacy, with prolonged use of one-way speaking valve. The results demonstrated that once patients achieve a threshold of 2-hours with no adverse events, there does not appear to be any limitations to extended use. The prolonged use of one-way speaking valves was safe in the ICU environment for periods up to 17 hours, whilst patients continued to participate in their normal ICU cares and therapies, including showering, eating and drink, mobilising, and participating therapy, all whilst having the ability to communicate as desired. In contrast to previous studies, there were no statically significant clinical improvements with the use of a one-way speaking valve, however only physiological efficacy was studied, and no assumption on psychological efficacy could be made. As clinical skills and knowledge have improved through research, so has the model of care of ICU. No longer are patients heavily sedated for prolonged periods of time, and ICU survivorship is no longer an optimal outcome. The short and long-term quality of life of ICU patients has been under surveillance in recent years, with a new focus on reducing long-term consequences of ICU admission. Although the results from both the systematic review and observational study demonstrated no adverse clinical events, and potential improvements across physiological domains, psychological efficacy has not yet been thoroughly explored. These results indicate there is a potential for further research, particularly into psychological, and patient and family centered outcomes. Exploring the benefits of earlier, and longer, communication for patients with tracheostomies may help to improve outcomes such as Post Intensive Care Syndrome and ICU delirium.