Changes in Regional Lung Ventilation Following Mechanical Insufflation-Exsufflation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 32
- 试验地点
- 2
- 主要终点
- Reduction in the regional ventilation delays and Increase in homogeneity of ventilation post MIE vs baseline.
研究概览
简要总结
Patients with NMD can suffer from a range of respiratory problems due to respiratory muscle weakness. Cough muscle weakness worsens secretion clearance from the airways, and increases the risk of infection. As a result, these patients often require chest physiotherapy or are supported with devices to aid clearance (such as mechanical insufflation-exsufflation) to reduce the risk of infection. Although evidence supports the use of these devices, the optimal technique or settings on the device are not clear.
Electrical impedance tomography (EIT) is a new technology that involves wearing a belt of sensors around the chest that provides information on how well the lungs are being filled with air. It allows a non-invasive assessment of the effect of each secretion clearance technique on lung ventilation in real-time.
This study aims to compare how well the lung is filled with air between three different techniques for secretion clearance (clearing mucus and phlegm from the airways), in order to determine which of the techniques is the most effective, in patients with NMD.
详细描述
Electrical Impedance Tomography (EIT) is a non-invasive, bedside monitoring technique that provides semi-continuous, real-time information about the regional distribution of the changes in electrical resistivity of the lung tissue due to variations in ventilation in relation to a reference state.
Information is gained by repeatedly injecting small alternating electric currents (usually 5 mA) at high frequency of 50 - 80 kHz through a system of skin electrodes (usually 16) applied circumferentially around the thorax in a single plane between the 4th and 6th intercostal space. While an adjacent pair of electrodes 'injects' the current ('adjacent drive configuration'), all the remaining adjacent passive electrode pairs measure the differences in electric potential. A resistivity (impedance) image is reconstructed from this data by a mathematical algorithm using a two dimensional model and a simplified shape to represent the thoracic cross-section.
The resulting image possesses a high temporal and functional resolution making it possible to monitor dynamic physiological phenomena (e.g., delay in regional inflation or recruitment) on a breath by breath basis. It is important to realize that the EIT images are based on image reconstruction techniques that require at least one measurement on a well-defined reference state. All quantitative data are related to this reference and can only indirectly quantify (relative) changes in local lung impedance (but not absolute).
Patients with respiratory muscle weakness have reduced cough strength and this can cause difficulties with clearing respiratory secretions. This impaired secretion clearance can lead to respiratory infections and acutely can causing small airway occlusion with subsequent ventilation-perfusion mismatch adversely effecting pulmonary mechanics. The use of cough assist devices, such as mechanical insufflation-exsufflation (MIE) can improve secretion clearance. Although there is evidence that these devices can improve secretion clearance the optimal pressures or technique required to provide effective secretion clearance is not known. Furthermore the use of high pressure swings that are now frequently used in clinical practice could lead to lung derecruitment. The use of EIT would allow a novel and effective method of assessing the ability to clear secretions and optimise ventilated lung in neuromuscular patients with poor cough and assess post procedure derecruitment.
MIE: A pilot physiological study will be performed in patients with neuromuscular disease with acute (10 patients) and chronic (10 patients) secretion management issues that require clinical use of MIE. These patients will be studied using 3 different clearance strategies low pressure MIE, higher pressure MIE and standard airway techniques. The project will assess differences in regional ventilation following augmented airway clearance and inform potential endpoints and feasibility for a larger trial regarding speed of recovery from respiratory infections in patients with neuromuscular disease.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Neuromuscular disease e.g. muscular dystrophy, motor neurons disease
- •Respiratory muscle weakness (FVC <60%, snip <60%, sleep disordered breathing)
- •Clinical evidence of respiratory secretions or cough PEF <270 and history of LRTI
- •Documented clinical stability by supervising clinician
- •Inclusion Criteria: ACUTE
- •Neuromuscular disease e.g. muscular dystrophy, motor neurons disease
- •Respiratory muscle weakness (FVC <60%, snip <60%, sleep disordered breathing)
- •Clinical evidence of respiratory secretions or cough PEF <270
- •Admitted with respiratory deterioration
排除标准
- •Decompensated respiratory failure (pH < 7.35)
- •Pregnancy
- •Aged <18, >80
- •Change in ventilator settings in preceding 4 weeks
- •Significant physical or psychiatric co-morbidity that would prevent compliance with trial protocol
- •Exclusion Criteria: ACUTE
- •Decompensated respiratory failure (pH < 7.35), at time of recruitment
- •Pregnancy
- •Aged <18, >80
- •Significant physical or psychiatric co-morbidity that would prevent compliance with trial protocol
结局指标
主要结局
Reduction in the regional ventilation delays and Increase in homogeneity of ventilation post MIE vs baseline.
时间窗: 1 day
次要结局
- Change in neural respiratory drive (EMGpara) pre to post clearance(1 day)
- Change in gas exchange (SpO2 and tcCO2)(1 day)
- Subjective patient comfort (Visual analogue scale - VAS)(1 day)