We report a case of post-extubation respiratory failure due to insufficient airway mucus expectoration that was successfully treated using mechanical insufflation-exsufflation (MI-E). A 32-year-old woman with a long-term history of steroid therapy for Blau syndrome was admitted to our intensive care unit with refractory hypoxemia due to pneumonia associated with the novel coronavirus disease 2019. Mechanical ventilation with veno-venous extracorporeal membrane oxygenation (VV-ECMO) was required due to severe hypoxemia. She was weaned from VV-ECMO on the 10th day and extubated on the 13th day. A few hours after extubation, she presented respiratory distress due to massive pulmonary atelectasis caused by sputum accumulation as a result of the impaired cough reflex. MI-E was applied to facilitate coughing and sputum expectoration. MI-E dramatically improved the atelectasis and prevented reintubation. This case suggests that MI-E, which is primarily used to treat chronic neuromuscular diseases, may also be effective in treating acute respiratory failure.

BACKGROUND: Mechanical insufflation-exsufflation (MI-E) is a cough augmentation technique used to support people with an ineffective cough. MI-E can be complex due to the number of different pressure, flow, and temporal setting adjustments needed to optimize cough efficacy. Many clinicians identify inadequate training, limited experience, and low confidence as barriers to MI-E use. The purpose of this study was to determine if an online education course could improve confidence and competence in the delivery of MI-E.
METHODS: An e-mail invitation to participate was disseminated to physiotherapists with a caseload that involved airway clearance for adults. The exclusion criteria were self-reported confidence and clinical expertise in MI-E. The education was created by physiotherapists with extensive experience in the provision of MI-E. The education material reviewed theoretical and practical components and was designed to take 6 h to complete. Physiotherapists were randomized to either the intervention group, who had 3 weeks of access to the education or the control group who received no intervention. Respondents in both groups completed a baseline and a post-intervention questionnaire by using visual analog scales, 0 to 10, with the primary outcomes being confidence in the prescription and confidence in the application of MI-E. Ten multiple-choice questions that covered key components of MI-E fundamentals were also completed at baseline and post-intervention.
RESULTS: The intervention group had a significant improvement in the visual analog scale after the education period with a between-group difference of mean 3.6 (95% CI 4.5 to 2.7) for prescription confidence and mean 2.9 (95% CI 3.9 to 1.9) for application confidence. There was also an improvement in the multiple-choice questions with a between-group difference of mean 3.2 (95% CI 4.3 to 2).
CONCLUSIONS: Access to an evidence-based online education course improved confidence in the prescription and application of MI-E, and may be a valuable tool for training clinicians in the application of MI-E.

BACKGROUND: Despite potential benefits, it is not known how widely physiotherapists use mechanical insufflation-exsufflation devices on UK adult intensive care units. This survey aimed to describe mechanical insufflation-exsufflation use in UK adult intensive care units.
METHODS: Cross-sectional electronic survey of physiotherapists working in a permanent post on adult intensive care units.
RESULTS: One hundred and sixty-six complete surveys were available for analysis, reflecting a diverse geographical spread. Nearly all (98%; 163/166) clinicians had access to mechanical insufflation-exsufflation. The estimated frequency of use varied, with the majority reporting weekly or monthly use (52/163, 32%; 50/163, 31%, respectively). Nearly all clinicians (99%) used mechanical insufflation-exsufflation with extubated patients. In contrast, around half of respondents (86/163, 53%) used mechanical insufflation-exsufflation with intubated patients, with a range of perceived barriers reported.
CONCLUSIONS: Mechanical insufflation-exsufflation devices are widely available on UK adult intensive care units, with use more common in extubated patients. Barriers to mechanical insufflation-exsufflation use in the intubated population warrant further investigation.

When the ability to cough is impaired, secretion clearance may be assisted and augmented with mechanical insufflation-exsufflation (MI-E). In some individuals, the efficacy of MI-E may be hampered by counterproductive upper airway reactions, where the airways close in response to positive pressures. To fully utilize the therapeutic potential inherent in the MI-E technology, we need a better understanding of the pathophysiology behind these untoward reactions. There is increasing interest in monitoring and measuring upper airway responses to MI-E and how such information can be used to optimize MI-E settings. The purpose of this narrative review is to increase the theoretical understanding of the larynx as a respiratory organ, summarize the current literature in the area, and provide insight into how this knowledge can affect current clinical practice.

BACKGROUND: Cough augmentation techniques are taught by health-care providers to improve secretion clearance and to help prevent respiratory infections in children with neuromuscular disease. There is some evidence of the effectiveness of a manually assisted cough when applied by health-care providers. However, it is unknown whether parents and caregivers may also be effective in applying manually assisted cough. The aim of this study was to evaluate whether parents and caregivers are effective at applying a manually assisted cough to a child with neuromuscular disease after being taught by a health-care provider.
METHODS: For this prospective cohort study, children and their parents or caregivers were recruited from neuromuscular clinics in the Sydney Children\'s Hospitals Network. Cough peak flow was the outcome measure for the strength of the child\'s cough. Children were eligible to participate if their unassisted cough peak flow at baseline was <270 L/min. Parents and caregivers were taught a manually assisted cough by a physiotherapist before being measured. The cough peak flow was measured in the following order: (1) during an unassisted cough as baseline, (2) during a manually assisted cough performed by a physiotherapist, (3) during a manually assisted cough performed by a parent or caregiver, and (4) during an unassisted cough after intervention.
RESULTS: Twenty-eight children (24 boys, 4 girls; mean ± SD age, 12 ± 3 y) completed the study. No clinically or statistically significant changes were found in the cough peak flow after the application of a manually assisted cough by parents or caregivers (95% CI -11 to 11 L/min) or by physiotherapists (95% CI -6 to 14 L/min).
CONCLUSIONS: Parents and caregivers and health-care providers were ineffective at increasing cough peak flow in children with neuromuscular weakness when applying a manually assisted cough. A single training session was insufficient for a parent or caregiver to be able to apply a manually assisted cough effectively on his or her child with neuromuscular weakness. Further research is warranted to guide recommendations on how best to equip parents and caregivers with the skills to help manage children with neuromuscular disease.

BACKGROUND: Respiratory complications represent the major cause of death in amyotrophic lateral sclerosis (ALS). Noninvasive respiratory support is the mainstay therapy, but treatment becomes challenging as the disease progresses, possibly due to a malfunctioning larynx, which is the entrance to the airways. We studied laryngeal response patterns to mechanically assisted cough (mechanical insufflation-exsufflation) as ALS progresses.
METHODS: This prospective longitudinal study of 13 consecutively included subjects with ALS were followed up during 2011-2016 with repeated tests of lung function, neurological status, and laryngeal responses to mechanical insufflation-exsufflation using video-recorded flexible transnasal fiberoptic laryngoscopy.
RESULTS: Follow-up time was median 17 (range 6-59) months. In total, 751 laryngoscopy recordings from 67 individual examinations (median 4 per subject, range 2-11 per subject) were analyzed. Adverse laryngeal events that developed with disease progression during insufflation included adduction of true vocal folds in 8 of 9 spinal-onset subjects and adduction of aryepiglottic folds in all subjects, initially at the highest positive pressure and prior to onset of other bulbar symptoms in spinal-onset subjects. As cough became less expulsive with disease progression, laryngeal adduction occurred at lower insufflation pressures. Retroflex movement of the epiglottis was observed in 7 of 13 subjects regardless of insufflation pressures and independent of bulbar involvements. Backward movement of the tongue base occurred regardless of insufflation pressures in all but 1 subject. During exsufflation, constriction of the hypopharynx was observed in all subjects regardless of the presence of bulbar symptoms, after the adverse events that occurred during insufflation.
CONCLUSIONS: Applying high insufflation pressures during mechanically assisted cough in ALS can become counterproductive as the disease progresses as well as prior to the onset of bulbar symptoms. The application of positive inspiratory pressures should be tailored to the individual patient, and laryngoscopy during ongoing treatment appears to be a feasible tool.

Cough can be viewed as a continuum where extremes represent disease phenotypes. Under this unified concept, non-pharmacological treatment for the extremes of the cough spectrum includes both cough augmentation and cough control techniques. Supporting the cough motor output and exercising the cognitive control on coughing are the main directions of these techniques. Cough augmentation can be provided to patients who present low ability to generate adequate peak cough flows, with the aim to develop the sheering forces that are essential for effective airway clearance. On the other hand, individuals with high cough sensitivity or frequency can practice techniques for cough control, which incorporates a combination of education, retraining and psychological support. These techniques aim to empower patients to increase their supramedulary control on cough. Although hypotheses that are generated by the physiology of cough can support most non-pharmacological techniques, their exact mechanisms of effectiveness remain unclear.

BACKGROUND: Critically ill mechanically ventilated patients experience impaired airway clearance due to ineffective cough and impaired secretion mobilization. Cough augmentation techniques, including mechanical insufflation-exsufflation (MI-E), manually assisted cough, and lung volume recruitment, improve cough efficiency. Our objective was to describe use, indications, contraindications, interfaces, settings, complications, and barriers to use across Canada.
METHODS: An e-mail survey was sent to nominated local survey champions in eligible Canadian units (ICUs, weaning centers, and intermediate care units) with 4 telephone/e-mail reminders.
RESULTS: The survey response rate was 157 of 238 (66%); 78 of 157 units (50%) used cough augmentation, with 50 (64%) using MI-E, 53 (68%) using manually assisted cough, and 62 (79%) using lung volume recruitment. Secretion clearance was the most common indication (MI-E, 92%; manually assisted cough, 88%; lung volume recruitment, 76%), although the most common units (44%) used it <50% of the time. Use during weaning from invasive (MI-E, 21%; manually assisted cough, 39%; lung volume recruitment, 3%) and noninvasive ventilation (MI-E, 21%; manually assisted cough, 33%; lung volume recruitment, 21%) was infrequent. The most common diagnoses were neuromuscular disease (97%) and spinal cord injury (83%). Pneumothorax was the most frequently identified absolute contraindication for MI-E (93%) and lung volume recruitment (83%); rib fracture was most frequently identified for manually assisted cough (69%). MI-E mean inspiratory pressure was 31 cm H2O, and expiratory pressure was -32 cm H2O. Mucus plugging requiring tracheostomy inner change was the most frequent complication for MI-E (23%), chest pain for manually assisted cough (36%), and hypotension for lung volume recruitment (17%). The most commonly cited barriers were lack of expertise (70%), knowledge (65%), and resources (52%).
CONCLUSIONS: We found moderate adoption of cough augmentation techniques, particularly for secretion management. Lack of expertise and knowledge are potentially modifiable barriers addressed with educational interventions.

OBJECTIVE: To assess the ability of a mechanical in-exsufflator (MI-E), either alone or in combination with manual thrust, to augment cough in patients with neuromuscular disease (NMD) and respiratory muscle dysfunction.
METHODS: For this randomized crossover single-center controlled trial, patients with noninvasive ventilator-dependent NMD were recruited. The primary outcome was peak cough flow (PCF), which was measured in each patient after a cough that was unassisted, manually assisted following a maximum insufflation capacity (MIC) maneuver, assisted by MI-E, or assisted by manual thrust plus MI-E. The cough augmentation techniques were provided in random order. PCF was measured using a new device, the Cough Aid.
RESULTS: All 40 enrolled participants (37 males, three females; average age, 20.9±7.2 years) completed the study. The mean (standard deviation) PCFs in the unassisted, manually assisted following an MIC maneuver, MI-E-assisted, and manual thrust plus MI-E-assisted conditions were 95.7 (40.5), 155.9 (53.1), 177.2 (33.9), and 202.4 (46.6) L/min, respectively. All three interventions significantly improved PCF. However, manual assistance following an MIC maneuver was significantly less effective than MI-E alone. Manual thrust plus MI-E was significantly more effective than both of these interventions.
CONCLUSIONS: In patients with NMD and respiratory muscle dysfunction, MI-E alone was more effective than manual assistance following an MIC maneuver. However, MI-E used in conjunction with manual thrust improved PCF even further.

A major problem faced by patients with amyotrophic lateral sclerosis (ALS) in respiratory failure is the inability to cough effectively. Forty eligible ALS patients were randomized to the breath-stacking technique using a lung volume recruitment bag (n = 21) or mechanical insufflator-exsufflator MI-E (n = 19) and followed up at three-monthly intervals for at least 12 months or until death. Results showed that there were 13 episodes of chest infection in the breath-stacking group and 19 episodes in the MI-E group (p = 0.92), requiring 90 and 95 days of antibiotics, respectively (p = 0.34). The mean duration of symptoms per chest infection was 6.9 days in the breath-stacking group and 3.9 days in MI-E group (p = 0.16). There were six episodes of hospitalization in each group (p = 0.64). The chance of hospitalization, in the event of a chest infection, was 0.46 in the breath-stacking group and 0.31 in MI-E group (p = 0.47). Median survival in the breath-stacking group was 535 days and 266 days in the MI-E group (p = 0.34). The QoL was maintained above 75% of baseline for a median of 329 days in the breath-stacking group and 205 days in the MI-E group (p = 0.41). In conclusion, lack of statistically significant differences due to sub-optimal power and confounders precludes a definitive conclusion with respect to the relative efficacy of one cough augmentation technique over the other. This study however, provides useful lessons and informative data, needed to strengthen the power calculation, inclusion criteria and randomization factors for a large scale definitive trial. Until such a definitive trial can be undertaken, we recommend the breath-stacking technique as a low-cost, first-line intervention for volume recruitment and cough augmentation in patients with ALS who meet the criteria for intervention with non-invasive ventilation.