This is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in people with bulbar insufficiency; children and infants) and recommends when and how each technique should be applied.
There is general agreement that noninvasive ventilation (NIV) prolongs survival in amyotrophic lateral sclerosis (ALS) and that the main cause of NIV failure is the severity of bulbar dysfunction. However, there is no evidence that bulbar impairment is a contraindication for NIV. The aim of this study was to determine the effect of bulbar impairment on survival in ALS patients with NIV.ALS patients for whom NIV was indicated were included. Those patients who refused NIV were taken as the control group.120 patients who underwent NIV and 20 who refused NIV were included. The NIV group presented longer survival (median 18.50 months, 95% CI 12.62–24.38 months) than the no-NIV group (3.00 months, 95% CI 0.82–5.18 months) (p<0.001) and also in those patients with severe bulbar dysfunction (13.00 months (95% CI 9.49–16.50 months)versus3.00 months (95% CI 0.85–5.15 months), p<0.001). Prognostic factors for ALS using NIV, adjusted for NIV failure, were severity of bulbar dysfunction (hazard ratio (HR) 0.5, 95% CI 0.92–0.97; p=0.001) and time spent with oxygen saturation measured by pulse oximetry <90% (%sleepSpO2<90) using NIV (HR 1.12, 95% CI 1.01–1.24; p=0.02).Severe bulbar impairment in ALS does not always prevent NIV from being used, but the severity of bulbar dysfunction at NIV initiation and %sleepSpO2<90 while using NIV appear to be the main prognostic factors of NIV failure in ALS.
Decreased cough capacity during a respiratory infection is one of the main causes of acute respiratory failure and hospitalisation in amyotrophic lateral sclerosis (ALS). Objective: To determine whether a respiratory measurement could identify the effectiveness of cough capacity in ALS during a respiratory infection. Methods: This was a prospective study of all ALS patients who were treated at a respiratory care unit due to a respiratory infection from 2012 to 2016. The effectiveness of unassisted and assisted coughing was evaluated and respiratory function tests were performed during the acute episode. Results: Forty-eight ALS patients were enrolled, with only four having an effective unassisted cough. The variable which predicted unassisted cough effectiveness was peak cough flow (PCF) (OR 4499.27; 95%CI 3.60–3219086.19; p = 0.022) with a cut-off point of 2.77 L/s (166 L/min). For manually assisted coughing, the predictor of cough effectiveness was manually assisted PCF (cut-off point of 2.82–169 L/min) (OR 2198.602; 95% CI 3.750–1351691.42; p = 0.019). Mechanically assisted PCF (cut-off point of 2.95–177 L/min) was found to be the predictor of mechanically assisted coughing effectiveness (OR 23.40; 95% CI 2.11–258.96; p = 0.010). Conclusions: During a respiratory infection in ALS patients, the effectiveness of assisted and unassisted cough capacity depends on the PCF generated.
BACKGROUND: Mechanically assisted coughing with mechanical in-exsufflation (MI-E) is recommended for noninvasive management of respiratory secretions in amyotrophic lateral sclerosis (ALS). To improve the effectiveness of the technique, a new device combining MI-E with high-frequency oscillations (HFO) has been developed. This work aimed to assess the effect of HFO on the cough peak flow generated by MI-E in medically stable subjects with ALS. METHODS: This was a prospective study that included subjects with ALS in a medically stable condition. Cough peak flow generated by MI-E was measured in 4 situations: without HFO, with HFO during insufflation, with HFO during exsufflation, and with HFO in both cycles. The parameters used were: insufflation pressure of +40 cm H 2 O, exsufflation pressure of −40 cm H 2 O, insufflation time 2 s, exsufflation time 3 s, amplitude of oscillations 10 cm H 2 O, and frequency of oscillations 15 Hz. RESULTS: Forty-seven subjects with ALS were included: 66% males, 68.2 ± 9.2 y, 40% with bulbar onset, FVC = 1.7 ± 1.1 L, percent-of-predicted FVC = 54.4 ± 26.6%, cough peak flow = 3.8 ± 2.2 L/s, P Imax = −39.4 ± 26.4 cm H 2 O, revised ALS scale = 28.5 ± 9.3, Norris bulbar subscore = 26.1 ± 10.4. No statistical differences were found in cough peak flow generated by MI-E in the 4 situations (without HFO = 4.0 ± 1.2 L/s, with insufflation HFO = 3.9 ± 1.2 L/s, with exsufflation HFO = 4.1 ± 1.2 L/s, with in-exsufflation HFO = 3.9 ± 1.1 L/s). CONCLUSIONS: The addition of HFO to mechanically assisted coughing with MI-E does not have an effect on the cough peak flow of medically stable subjects with ALS.
BACKGROUND: Effectiveness of mechanical assisted coughing with insufflation-exsufflation (MI-E) in amyotrophic lateral sclerosis (ALS) depends largely on severity of bulbar dysfunction, which can generate different upper-airway responses. The aim of the study was to evaluate the use of graphs generated by MI-E in ALS to detect airway obstruction and set parameters to achieve an effective mechanically assisted coughing. METHODS: This was a prospective study enrolling patients with ALS. Several sessions with MI-E were applied, administering different insufflation-exsufflation (± 20, ± 30, ± 40, ± 50 cm H 2 O) levels in each session. The graphs produced were recorded and analyzed, and the results were used to select the parameters resulting in more effective MI-E. RESULTS: Sixty-nine subjects with ALS were included, yielding a total of 351 analyzed records. A pattern of obstruction during insufflation was detected in 34 subjects (50.7%) and of upper-airway collapse during exsufflation in 18 subjects (26%). The variable associated with obstruction during insufflation was bulbar upper motor neuron dysfunction (odds ratio 7.19 [95% CI 2.32–22.29], P = .001), whereas bulbar lower motor neuron dysfunction was related to upper-airway collapse during exsufflation (odds ratio 0.32 [95% CI 0.11–0.98], P = .046). After parameters were adjusted, in 68 subjects (98.55%) an effective MI-E was achieved. The only variable that predicted absence of alterations in the graphs was Norris bulbar score (odds ratio 0.87 [95% CI 0.78–0.96], P = .007). CONCLUSIONS: Analysis of graphics generated by applying MI-E in ALS was an effective method to detect upper-airway responses and select optimal set parameters. Obstruction during insufflation is related to bulbar upper motor neuron dysfunction and collapse during exsufflation to bulbar lower motor neuron dysfunction.