Mouthpiece ventilation in neuromuscular disorders: Narrative review of technical issues important for clinical success

Home Noninvasive Ventilation in COPD

Evidence is increasing that long-term noninvasive ventilation (LTNIV) can improve outcomes in individuals with severe, hypercapnic COPD. Although the evidence remains unclear in some aspects, LTNIV seems to be able to improve patient-related and physiologic outcomes like dyspnea, FEV1 and partial pressure of carbon dioxide (Pco2) and also to reduce rehospitalizations and mortality. Efficacy generally is associated with reduction in Pco2. To achieve this, an adequate interface (mask) is essential, as are appropriate ventilation settings that target the specific respiratory physiologic features of COPD. This will ensure comfort, synchrony, and adherence that will result in physiologic improvements. This article briefly reviews the newest evidence and current guidelines on LTNIV in severe COPD. It describes an actual patient who benefitted from the therapy. Finally, it provides strategies for initiating and optimizing this LTNIV in COPD, discussing high-pressure noninvasive ventilation, optimization of triggering, and control of inspiratory time. As demand increases, clinicians will need to be familiar with this therapy to reap its benefits, because inadequately adjusted LTNIV will not be tolerated or effective.

The feasibility of using mouthpiece ventilation in the intensive care unit for post-extubation breathing support after acute tetraplegia

STUDY DESIGN

A prospective cohort of patients with acute tetraplegia.

OBJECTIVES

This study aimed to determine the feasibility of using mouthpiece ventilation (MPV) in the intensive care unit (ICU) for patients who are extubated after suffering an acute cervical spinal cord injury (CSCI).

SETTING

ICU, Princess Alexandra Hospital, Brisbane Australia.

METHODS

New admissions to ICU in the 14 months between April 2017 and June 2018 with a CSCI who underwent intubation were assessed for inclusion. MPV was provided to consenting participants (who were deemed likely to be able to maintain ventilation on their own) at the time of extubation and was utilised in addition to standard care while participants were awake. MPV settings, usage, and support hours to educate and facilitate MPV were collected. Feedback from participants and clinical staff was gathered throughout the study. Pre- and post-extubation measures of forced vital capacity (FVC), the frequency of endotracheal suction of sputum, and gas exchange using ventilation-perfusion ratios were recorded along with the incidence of reintubation.

RESULTS

Fourteen participated in utilising MPV with 16 episodes of extubation. The average time per participant to have MPV titrated and bedside data collected was 178 minutes. Data from 16 episodes of extubation have been included. Three of the 14 participants failed initial extubation. Feedback from participants and clinicians has been positive and constructive, enabling MPV settings to be adapted to the person with acute CSCI during this pilot study.

CONCLUSION

MPV is feasible to use post-extubation for people with CSCI in ICU. Pressure control mode MPV was deemed the most suitable for newly extubated acute CSCI patients. Intensive clinical support is required initially to provide education prior to MPV, and at the time of extubation for both patient and treating clinicians. Both report it to be a useful adjunct to ICU treatment.

What Circuits, Masks and Filters Should Be Used in Home Non-Invasive Mechanical Ventilation

Most of the published reviews about non-invasive home ventilation mainly reflect the technical aspects of ventilators. There is much less information about the consumables most used at home. However, the choice of a good interface or tubing system can lead to physiological changes in the patient–ventilator interaction that the clinician should be aware of. These physiological changes may affect the performance of the ventilator itself, the reliability of monitoring and, of course, the comfort of the patient. The use of different circuits, masks or filters is therefore related to the concepts of rebreathing, compressible volume, instrumental dead space or leak estimation and tidal volume. Through certain bench experiments, it is possible to determine the implications that each of these elements may have in clinical practice.

Chronic Neuromuscular Respiratory Failure and Home Assisted Ventilation

Chronic respiratory failure is a common, important complication of many types of neuromuscular and chest wall disorders. While the pathophysiology of each disease may be different, these disorders can variably affect all muscles involved in breathing, including inspiratory, expiratory, and bulbar muscles, ultimately leading to chronic respiratory failure and hypoventilation. The use of home assisted ventilation through noninvasive interfaces aims to improve the symptoms of hypoventilation, improve sleep quality, and, when possible, improve mortality. An increasing variety of interfaces has allowed for improved comfort and compliance. In a minority of scenarios, noninvasive ventilation is either not appropriate or no longer effective due to disease progression, and a transition to tracheal ventilation should be considered.

Building a home ventilation programme: population, equipment, delivery and cost

Home mechanical ventilation (HMV) improves quality of life and survival in patients with neuromuscular disorders (NMD). Developing countries may benefit from published evidence regarding the prevalence, cost of equipment, technical issues and organisation of HMV in NMD, facilitating the development of local turn-key HMV programmes. Unfortunately, such evidence is scattered in the existing literature. We searched Medline for publications in English and French from 2005 to 2020. This narrative review analyses 24 international programmes of HMV. The estimated prevalence (min-max) of HMV is ±7.3/100 000 population (1.2-47), all disorders combined. The prevalence of HMV is associated with the gross domestic product per capita in these 24 countries. The prevalence of NMD is about 30/100 000 population, of which ±10% would use HMV. Nocturnal (8/24 hour), discontinuous (8-16/24 hours) and continuous (>16/24 hours) ventilation is likely to concern about 60%, 20% and 20% of NMD patients using HMV. A minimal budget of about 168€/patient/year (504€/100 000 population), including the cost of equipment solely, should address the cost of HMV equipment in low-income countries. When services and maintenance are included, the budget can drastically increase up to between 3232 and 5760€/patient/year. Emerging programmes of HMV in developing countries reveal the positive impact of international cooperation. Today, at least 12 new middle, and low-income countries are developing HMV programmes. This review with updated data on prevalence, technical issues, cost of equipment and services for HMV should trigger objective dialogues between the stakeholders (patient associations, healthcare professionals and politicians); potentially leading to the production of workable strategies for the development of HMV in patients with NMD living in developing countries.