Cough Flow Research Articles

Do proprioceptive neuromuscular facilitation techniques improve respiratory parameters and swallowing in people with multiple sclerosis: A randomized-controlled study

AimThis study aims to investigate the effects of Proprioceptive Neuromuscular Facilitation (PNF) techniques on respiratory parameters, swallowing, functional capacity, fatigue, and quality of life in people with Multiple Sclerosis (PwMS). MethodThirty-four PwMS were included and randomized into the PNF Group (mean age: 43.23±10.55/years) or Control Group (mean age:38.47±8.18/years). In the PNF group, head-neck, upper extremity, trunk, and breathing techniques were applied three days/eight weeks. The control group continued home-based breathing exercises. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow (PEF), forced expiratory flow 25–75 % (%FEF 25–75), peak cough flow (PCF), maximal inspiratory (MIP) and expiratory pressures (MEP) were and two minutes walking test (2MWT) were measured. Dysphagia in Multiple Sclerosis (DYMUS), Eating Assessment Tool (EAT-10), Fatigue Severity Scale (FSS) and Multiple Sclerosis Quality of Life (MusiQoL) were questioned. ResultsAfter treatment, MIP, MEP,%FEV1/FVCpred,%PEFpred,%FEF 25–75pred, PCF, DYMUS, EAT-10, FSS, and MUSIQoL were improved in the PNF group while MIP, MEP, PCF, DYMUS, EAT-10, MUSIQoL, and 2 MWT were improved in the control group (p < 0.05 for all). In the between-group analysis of the mean differences, the%FEV1pred was significantly different in favor of the PNF Group (p = 0.011), and MIP was significantly different in favor of the Control Group (p = 0.013). DiscussionThe PNF techniques can improve respiratory muscle strength, respiratory functions, cough efficiency, swallowing functions, and quality of life in mild to moderate PwMS. However, these improvements were not superior except for%FEV1pred compared to home-based breathing exercises.

Prognostic factors for tracheostomy early decannulation in acquired brain injury patients.

After severe brain injuries, a tracheostomy tube is usually inserted for respiratory support. This study aimed to clarify the prognostic factors for tracheostomy early decannulation in patients with acquired brain injuries. We retrospectively reviewed the medical records of inpatients with acquired brain injuries who underwent successful tracheostomy decannulation between March 2021 and June 2022. Fifty-six patients were included; median age was 68 (59-72) years; 28 (50%) were men; 28 (50%) underwent tracheostomy due to stroke. The median time to decannulation was 47 days. The patients were divided into the early and the late decannulation groups based on the median time, and compared. In univariate analysis, the early decannulation group had a higher BMI, peak cough flow, and acquired brain injuries due to trauma, and a lower penetration-aspiration scale score, duration of antibiotic use, and duration of oxygen use. Multivariate Cox regression analysis revealed that a higher initial peak cough flow [hazard ratio (HR) 1.142; 95% confidence interval (CI) 0.912-0.954; P < 0.001] and lower duration of oxygen use (HR 0.930; 95% CI 0.502-0.864; P = 0.016) were independent factors for early tracheostomy decannulation, with each unit increase in peak cough flow corresponding to a 14.2% increase and each additional day of duration of oxygen use corresponding to a 7.0% decrease in the likelihood of early decannulation. In conclusion, key prognostic factors for early tracheostomy decannulation were identified as the initial cough strength and duration of oxygen use. These results could play important role in decannulation plans for patients with tracheostomy tube.

Pilot observational cohort study to determine whether waveform and flow traces from mechanical insufflation–exsufflation (MI-E) can be used to identify laryngeal responses to MI-E and thus optimise treatment algorithms in neuromuscular patients in a tertiary centre: a protocol description

IntroductionPatients with neuromuscular disease often have a weak and ineffective cough due to respiratory muscle weakness. One treatment option is mechanical insufflation–exsufflation (MI-E), also known as cough assist, which is...

Differences in cough strength, respiratory function, and physical performance in older adults with and without low swallowing function in the repetitive saliva swallowing test.

[Purpose] In older adults, the risk of aspiration pneumonia increases because of coexisting factors such as age-related decline in swallowing function, inefficient cough, reduced respiratory function, and poor physical performance. This study aimed to investigate the differences in cough strength, respiratory function, and physical performance in community-dwelling ambulatory older adults with and without low swallowing function. [Participants and Methods] In 225 community-dwelling ambulatory older adults, swallowing function (the repetitive saliva swallowing test, RSST), cough strength (peak cough flow), lung function (forced vital capacity, forced expiratory volume in 1 second/forced vital capacity), respiratory muscle strength (maximum inspiratory and expiratory pressures), and physical performance (30-second chair stand test and Timed Up and Go test) were evaluated. Participants with low swallowing function in RSST (low RSST group) were compared to age- and sex-matched participants without low swallowing function (control group). [Results] Peak cough flow and maximum inspiratory and expiratory pressures were significantly lower in the low RSST group (n=14) than the control group (n=14). [Conclusion] These preliminary results suggest that community-dwelling ambulatory older adults with low swallowing function in RSST might have lower cough and respiratory muscle strength, even if they have relatively preserved lung function and physical performance.

폐이식 수혜자에 대해 적용한 장기간 호흡재활프로그램의 효과

Purpose: The purpose of this study was to provide long-term pulmonary rehabilitation program (PR) to lung transplant recipients for more than a year and verify their effectiveness.&#x0D; Methods: A 52-year-old female patient who had bilateral lung transplantation received an outpatient PR 3 times a week for a total of 97 weeks. The PR applied was composed of aerobic exercise, strength exercise, breathing exercise, flexibility exercise, and home exercise education. Evaluation was performed on the participant at 3, 6, 9, 12, and 24 months after surgery. For each period, the following parameters were determined: 6-minute walk distance (6MWD), grip strength, respiratory muscle strength, lung function, peak cough flow rate, skeletal muscle mass (SMM), and skeletal muscle index (SMI).&#x0D; Results: The 6MWD increased up to 12 months following surgery, and exercise-induced hypoxemia occurred only 3 months following surgery. The grip strength increased up to 12 months after surgery and decreased at 24 months after surgery. The MIP increased up to 12 months after surgery, and the MEP increased until 24 months after surgery. The FVC increased up to 12 months following surgery and FEV1 increased up to 24 months following surgery. PCF increased up to 12 months after surgery. Body weight also increased steadily until 24 months postoperatively. SMM and SMI increased up to 12 months after surgery, and SMI decreased at 24 months following surgery.&#x0D; Conclusion: It is essential that the PR for lung transplant recipients be applied intensively in less than 12 months after surgery, and the goal of the PR should be configured for the purpose of management in more than 12 months following surgery.

PULMONARYFUNCTIONINNEUROMUSCULARDISEASES

Respiratory functional assessment in patients with neuromuscular diseases allows us to quantify lung volumes and capacities, cough flows and the effectiveness of of ventilation. Pulse oximetry and non-invasive monitoring of exhaled carbon dioxide are also essential for the non-invasive assessment of hypoventilation associated with ventilatory muscle and cough insufficiency. In this way, it is possible to detect the objective needs for therapeutic assistance and implement health policies appropriate to the needs of this population.

Exploring the Feasibility of a Comprehensive Screening for Voice and Swallowing Function in Post-Extubation Patients: A Pilot Study

Objectives. This pilot study aimed to identify and test a battery of time-efficient and cost-effective voice and swallowing screening tools for post-extubated patients in Chile. Methods. A panel of four experts selected and rated voice and swallowing screening tools. Seven measures were selected: smoothed cepstral peak prominence (CPPS) and maximum phonation time (MPT) for voice assessment, Volume-Viscosity Swallow Test (V-VST) for swallowing, voluntary and reflex peak cough flow for cough assessment, Eating Assessment Tool-10 (EAT-10), and Vocal Symptom Scale (VoiSS) for patient-reported outcomes. These tools were applied to four post-extubation patients within 48-72 hours post-hospital discharge, alongside the assessment of 17 matched controls. Results. Post-extubation patients showed significantly shorter MPT, lower CPPS values, increased V-VST dysphagia signs, reduced voluntary peak cough flow, and more pronounced symptoms on both the VoiSS and EAT-10 compared to controls. Limitations. The study had a modest sample size and relied solely on clinical screening tools.Value. This pilot study suggests a feasible and cost-effective approach to voice and swallowing screening for post-extubation patients, valuable in resource-constrained settings.Conclusion. While these accessible tools are not gold-standard assessments, they offer valuable insights and can guide future research. This study underscores the potential of selected tools in facilitating early detection of voice and swallowing disorders in post-extubation patients.

Mechanically assisted cough strategies: user perspectives and cough flows in children with neurodisability.

Mechanical insufflation-exsufflation (MI-E) is used to augment cough in children with neurodisability. We aimed to determine the user comfort and cough flows during three MI-E strategies, and to predict factors associated with improved comfort and cough flows. This multicentre, crossover trial was done at four regional hospitals in Norway. Children with neurodisability using MI-E long term via mask were enrolled. In randomised order, they tested three MI-E setting strategies (in-/exsufflation pressure (cmH2O)/in (In)- versus exsufflation (Ex) time): 1) "A-symmetric" (±50/In=Ex); 2) "B-asymmetric" (+25- +30)/-40, In>Ex); and 3) "C-personalised", as set by their therapist. The primary outcomes were user-reported comfort on a visual analogue scale (VAS) (0=maximum comfort) and peak cough flows (PCF) (L·min-1) measured by a pneumotachograph in the MI-E circuit. We recruited 74 children median (IQR) age 8.1 (4.4-13.8) years, range 0.6-17.9, and analysed 218 MI-E sequences. The mean±sd VAS comfort scores were 4.7±2.96, 2.9±2.44 and 3.2±2.46 for strategies A, B and C, respectively (A versus B and C, p<0.001). The mean±sd PCF registered during strategies A, B and C were 203±46.87, 166±46.05 and 171±49.74 L·min-1, respectively (A versus B and C, p<0.001). Using low inspiratory flow predicted improved comfort. Age and unassisted cough flows increased exsufflation flows. An asymmetric or personalised MI-E strategy resulted in better comfort scores, but lower PCF than a symmetric approach utilising high pressures. All three strategies generated cough flows above therapeutic thresholds and were rated as slightly to moderately uncomfortable.

Spinal Muscular Atrophy Type 1 Survival Without New Pharmacotherapies: Two Treatment Paradigms.

The aims of the study are to present noninvasive respiratory management outcomes using continuous noninvasive ventilatory support and mechanical in-exsufflation from infancy for spinal muscular atrophy type 1 and to consider bearing on new medical therapies. Noninvasive ventilatory support was begun for consecutively referred symptomatic infants with spinal muscular atrophy type 1 from 1 to 10 mos of age. Intercurrent episodes of respiratory failure were managed by intubation then extubation to continuous noninvasive ventilatory support and mechanical in-exsufflation despite failing ventilator weaning and extubation attempts. Intubations, tracheotomies, and survival were monitored. Of 153 patients with spinal muscular atrophy 1 consecutively referred since 1995, 37 became continuous noninvasive ventilatory support dependent, almost half before 10 yrs of age. Of the 37, 18 required continuous noninvasive ventilatory support for a mean 18.6 ± 3.3 yrs to a mean 25.3 (range, 18-30) yrs of age, dependent from as young as 4 mos of age with 0 to 40 ml of vital capacity. One of the 18 died from COVID-19 acute respiratory distress syndrome at age 24 after 23 yrs of continuous noninvasive ventilatory support. Extubation success rate of 85% per attempt (150/176) resulted in only one undergoing tracheotomy. Medical treatments begun during the first 6 wks of age convert spinal muscular atrophy 1 into spinal muscular atrophy 2 or 3 but cough flows remain inadequate to avoid many pneumonias that, once resolved by a treatment paradigm of extubation to continuous noninvasive ventilatory support and mechanical in-exsufflation, eliminates need to resort to tracheotomies.

Deterioration of Cough, Respiratory, and Vocal Cord Functions in Patients with Multiple System Atrophy.

The purpose of this study was to clarify changes in cough function in patients with multiple system atrophy (MSA). Seventeen probable patients with MSA were studied. Peak cough flow (PCF), respiratory function (percentage of vital capacity, percentage of forced vital capacity, and percentage of predicted forced expiratory volume in one second), respiratory muscle strength (percentage of maximal inspiratory mouth pressure and percentage of maximal expiratory mouth pressure), and maximum phonation time (MPT) were assessed. Walking ability, disease duration, possibility of air stacking, Unified MSA Rating Scale (UMSARS), and Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III were also assessed. Data were separately analyzed for ambulatory and non-ambulatory groups categorized by Functional Ambulation Categories. PCF, respiratory function, respiratory muscle strength, and MPT were significantly lower in the non-ambulatory group than in the ambulatory group. On the other hand, no correlation between PCF and disease duration was observed. A significant number of patients in the non-ambulatory group were unable to hold their breath. The UMSARS and MDS-UPDRS Part III in the non-ambulatory group were significantly higher than in the ambulatory group. It was concluded that ambulatory dysfunction is associated with the decline of cough function and respiratory-related function in patients with MSA.

Effect of body position on peak expiratory flow during mechanical insufflation–exsufflation in people with cervical spinal cord injury: a pilot study

This prospective pilot study investigated the influence of body position on peak cough flow (PCF) during mechanical insufflation–exsufflation (MI-E) treatment in people with tetraplegia. Fifteen participants with cervical spinal cord injury (C-SCI) were randomized into two groups, which differed in the starting position, that is, the patients were either supine or reclined. Four sessions of MI-E in alternating positions with each session comprising three different maneuvers: five voluntary coughs, five MI-E-assisted coughs, and five MI-E-assisted with manual thrusts were performed with continuous airflow measurement reporting PCF from every cough. PCF was associated with the application maneuvers, total insufflation volume (TIV), and interaction between position and maneuvers but not with the application position. The estimated mean PCF was 1.808, 3.529, and 3.925 L/s when supine and 1.672, 3.598, and 3.909 L/s when reclined from voluntary cough, MI-E, and MI-E with manual thrust, respectively. The estimated PCF change compared to voluntary cough was 1.721 (95% CI, 1.603–1.838) L/s from the combined MI-E and 2.116 (95% CI, 2.005–2.228) L/s from the MI-E with manual thrust, calculated from the linear mixed-model analysis. PCF moderately correlated with TIV (R2 = 0.64). Therefore, either position can be used for C-SCI patients as long as MI-E can be performed with manual thrust and sufficient TIV is provided.

Accumulated Secretions and Associated Aerodigestive Function in Patients With Dysphagia.

Accumulated pharyngo-laryngeal secretions are associated with dysphagia, aspiration, and poor health outcomes. Despite ongoing developments in the evaluation of pharyngo-laryngeal secretions, understanding of the underlying mechanisms is limited. Pathophysiology associated with accumulated secretions is needed to guide tailored, targeted treatment pathways. This study reports the prevalence of accumulated pharyngo-laryngeal secretions in a large acute care caseload and explores the relationship between secretions and aerodigestive function. Consecutive inpatients (N = 222) referred for flexible endoscopic evaluation of swallow (FEES) with suspected dysphagia following assessment by a speech-language pathologist were recruited (43% neurological, 22% neurosurgical, 20% critical care, 15% other), and 250 standardized FEES were completed (222 first FEES, 28 repeat FEES). The assessment protocol included secretion assessment using the New Zealand Secretion Scale (NZSS), pharyngeal squeeze maneuver, laryngeal motor and sensory assessment, Penetration-Aspiration Scale, and Yale Pharyngeal Residue Severity Rating Scale. Urge-to-clear ratings were collected during endoscopy. Cough peak expiratory flow and swallow frequency measures were also collected, as well as clinical outcomes at time of discharge. There was a high incidence of accumulated secretions, with 77% of inpatients having elevated NZSS (Mdn = 3, range: 0-7) and 37% with pooled laryngeal secretions. Accumulated secretions were associated with reduced swallow frequency, reduced laryngeal adductor reflex, impaired pharyngeal squeeze maneuver, and peak expiratory flow. NZSS scores also correlated with swallow measures (Penetration-Aspiration Scale and Yale Pharyngeal Residue Severity Rating Scale) and patient outcomes including diet recommendations at discharge and pneumonia during admission. This large study contributes to evidence associating both sensory and motor impairments with secretion accumulation and aspiration risk. Further exploration of the key physiological mechanisms contributing to accumulated secretions will serve as markers to provide proof of principle for targets for secretion management protocols. https://doi.org/10.23641/asha.24101667.

Transcutaneous electrical diaphragmatic stimulation in mechanically ventilated patients: a randomised study

BackgroundFew specific methods are available to reduce the risk of diaphragmatic dysfunction for patients under mechanical ventilation. The number of studies involving transcutaneous electrical stimulation of the diaphragm (TEDS) is increasing but none report results for diaphragmatic measurements, and they lack power. We hypothesised that the use of TEDS would decrease diaphragmatic dysfunction and improve respiratory muscle strength in patients in ICU.MethodsWe conducted a controlled trial to assess the impact of daily active electrical stimulation versus sham stimulation on the prevention of diaphragm dysfunction during the weaning process from mechanical ventilation. The evaluation was based on ultrasound measurements of diaphragm thickening fraction during spontaneous breathing trials. We also measured maximal inspiratory muscle pressure (MIP), peak cough flow (PEF) and extubation failure.ResultsSixty-six patients were included and randomised using a 1:1 ratio. The mean number of days of mechanical ventilation was 10 ± 6.8. Diaphragm thickening fraction was > 30% at the SBT for 67% of participants in the TEDS group and 54% of the Sham group (OR1.55, 95% CI 0.47–5.1; p = 0.47). MIP and PEF were similar in the TEDS and Sham groups (respectively 35.5 ± 11.9 vs 29.7 ± 11.7 cmH20; p = 0.469 and 83.2 ± 39.5 vs. 75.3 ± 34.08 L/min; p = 0.83). Rate of extubation failure was not different between groups.ConclusionTEDS did not prevent diaphragm dysfunction or improve inspiratory muscle strength in mechanically ventilated patients.Trial registration: Prospectively registered on the 20th November 2019 on ClinicalTrials.gov Identifier NCT04171024.

Longitudinal Analysis of Respiratory Function of Different Types of Limb Girdle Muscular Dystrophies Reveals Independent Trajectories.

The prevalence and progression of respiratory muscle dysfunction in patients with limb girdle muscular dystrophies (LGMDs) has been only partially described to date. Most reports include cross-sectional data on a limited number of patients making it difficult to gain a wider perspective on respiratory involvement throughout the course of the disease and to compare the most prevalent LGMD subtypes. We reviewed the results of spirometry studies collected longitudinally in our cohort of patients in routine clinical visits from 2002 to 2020 along with additional clinical and genetic data. A linear mixed model was used to investigate the factors associated with the progression of respiratory dysfunction. We followed up 156 patients with 5 different forms of LGMDs for a median of 8 years (range 1-25 years). Of them, 53 patients had pathogenic variants in the Capn3 gene, 47 patients in the Dysf gene, 24 patients in the Fkrp gene, 19 in the Ano5 gene, and 13 in one of the sarcoglycan genes (SCG). At baseline, 58 patients (37.1%) had a forced vital capacity percentage predicted (FVCpp) below 80%, while 14 patients (8.9%) had peak cough flow (PCF) values below 270 L/min. As a subgroup, FKRP was the group with a higher number of patients having FVC <80% and/or PCF <270 L/min at initial assessment (66%). We observed a progressive decline in FVCpp and PCF measurements over time, being age, use of wheelchair, and LGMD subtype independent factors associated with this decline. Fkrp and sarcoglycan patients had a quicker decline in their FVC (Kaplan-Meier curve, F test, p < 0.001 and p = 0.02, respectively). Only 7 of the 58 patients with low FVCpp values reported symptoms of respiratory dysfunction, which are commonly reported by patients with FVCpp below 50%-60%. The number of patients ventilated increased from 2 to 8 during follow-up. Respiratory dysfunction is a frequent complication of patients with LGMDs that needs to be carefully studied and has direct implications in the care offered in daily clinics. Respiratory dysfunction is associated with disease progression because it is especially seen in patients who are full-time wheelchair users, being more frequent in patients with mutations in the Fkrp and sarcoglycan genes.

Evaluation of cough strength in bronchiectasis

Abstract&#x0D; Purpose: This study aimed to evaluate the cough strength in bronchiectasis patients. It also examined the relationship of cough strength with exercise capacity and quality of life. &#x0D; Materials and methods: The study included 24 bronchiectasis patients and 25 healthy individuals. Exercise capacity was evaluated with the 6-min walk test. Peak cough flow was assessed using a peak expiratory flow PEF cough-meter with a mouthpiece (M1). The quality of life was evaluated with Leicester Cough Questionnaire. &#x0D; Results: A significant difference was found between the groups in terms of PEF cough Meter, 6MWT, LCQ quality-of-life total score, and subdimension scores showed significant differences in favor of the control group (P &lt; 0.05). A positive correlation was observed between PEF cough Meter and the following variables: exercise capacity and Leicester total score (r = 0.780, P &lt; 0.000 and r = 0.885, P &lt; 0.000, respectively). &#x0D; Conclusion: This study found that cough strength was lower in bronchiectasis patients compared with healthy individuals. Cough strength could negatively affect exercise capacity and quality of life. Therefore, Cough strength should be added to the evaluation parameters.

Expiratory Muscle Strength Training in Multiple System Atrophy: A Pilot Study.

The effects of expiratory muscle strength training (EMST) has not yet been investigated in MSA patients. The primary objective was to test the effects of EMST on expiratory muscle strength and voluntary peak cough flow (vPCF) in patients with multiple system atrophy (MSA). The secondary objective was to assess the suitability of the pulmonary dysfunction index as a tool for identifying MSA patients with expiratory muscle weakness and reduced voluntary peak cough flow. This was an open label, non-controlled study, with an 8-week intensive home-based EMST protocol. The outcome measures included: maximal expiratory pressure (MEP) and vPCF. The sensitivity and specificity of the index of pulmonary dysfunction in the respiratory diagnostic process were assessed using receiver operating characteristic (ROC) analysis. Fifteen MSA patients were enrolled in the study. Twelve MSA patients completed the training period. After the training period, MEP significantly increased (P = 0.006). Differences in vPCF were not significant (P = 0.845). ROC analysis indicated that the overall respiratory diagnostic accuracy of the index of pulmonary dysfunction had an outstanding capability to detect patients at risk of less effective coughing and an acceptable capability of detecting patients with decreased expiratory muscle strength. These findings indicate non-significant differences in vPCF after 8 weeks of EMST. The index of pulmonary dysfunction appears to be a promising prognostic screening tool for identifying altered cough efficacy in MSA patients. Test cut-offs may be used to select an appropriate respiratory physiotherapy technique.

Cut-Off Value of Voluntary Peak Cough Flow in Patients with Parkinson's Disease and Its Association with Severe Dysphagia: A Retrospective Pilot Study.

Background and Objectives. Swallowing and coughing reflexes are both closely associated with airway protection. Peak cough flow (PCF) is associated with dysphagia in several neurogenic diseases. In this study, we aimed to analyze the relationship between PCF and aspiration in Parkinson's disease (PD) and determine the cut-off value of PCF. Materials and Methods. We retrospectively analyzed the records of patients with PD who underwent a videofluoroscopic swallowing study and checked for PCF. A total of 219 patients were divided into an aspiration group (n = 125) and a non-aspiration group (n = 94). Results. Significantly lower PCF values were observed in the aspiration group compared to the non-aspiration group (132.63 ± 83.62 vs. 181.38 ± 103.92 L/min, p < 0.001). Receiver operating characteristic curve analysis revealed that a PCF cut-off value of 153 L/min (area under the receiver operating characteristic curve, 0.648; sensitivity, 73.06%; specificity, 51.06%) was associated with aspiration in PD. Additionally, a univariate analysis showed that the male sex, lower body mass indexes, higher Hoehn and Yahr scales, and PCF values of ≤153 L/min indicated an increased risk of aspiration. Conclusions. Through a multivariate analysis, we demonstrated that a PCF value ≤153 L/min was associated with an increased risk of aspiration (odds ratio 3.648; 1.797-7.407), highlighting that a low PCF is a risk factor for aspiration in patients with PD.

A Bioinspired Active Robotic Simulator of the Human Respiratory System

Pathologies affecting the respiratory system can lead to a debilitating decrease in quality of life and can be fatal. To test medical devices and implants for the human respiratory system, a simulation system that can reproduce multiple respiratory features is necessary. Currently available respiratory simulators only focus on reproducing flow rate profiles of breathing while coughing simulators focus on aerosol analysis. In this paper we propose a novel, bioinspired robotic simulator that can physically replicate both breathing and coughing flow rate characteristics of healthy adults. We conducted a study on 31 healthy adult participants to gather the flow rate measurement of normal breathing, deep breathing, breathing while running and coughing. Coughing flow rate profiles vary considerably between participants, making an accurate simulation of coughs a challenge. To enable cough flow rate simulation, a new methodology based on the identification of four cough phases, Attack, Decay, Sustain and Release (ADSR) and their parametrization was devised. This methodology leads to the unprecedented ability to reproduce diverse and complex coughing flow rate profiles. Our simulator is able to reproduce respiratory flows with a root mean square error (RMSE) of 1.8 L/min between normal participant breathing and its simulation, 5% of the maximum flow rate simulated for that participant (pMFR), an RMSE of 10.08 L/min for deep breathing, 18% of the pMFR and an RMSE of 13.29 L/min for exertion breathing, 17% of pMFR. For the simulation of an average cough we recorded an RMSE of 51.43 L/min, 13% of the pMFR and for a low flow rate cough an RMSE of 12.38 L/min, 9.5% of the pMFR. The presented simulator matches the fundamentals of human breathing and coughing, advancing the current capability of respiratory system simulators.

Assessing the effect of transcranial magnetic stimulation on peak cough flow in patients with supratentorial cerebral infarction: A retrospective cohort study.

Respiratory dysfunction following supratentorial cerebral infarction leads to pneumonia and is a major cause of mortality. Decreased voluntary cough function impairs the ability to clear mucus or secretions from the airways and increases the risk of aspiration pneumonia. Peak cough flow (PCF) is one of the objective tools for evaluating voluntary cough function. Repetitive transcranial magnetic stimulation (rTMS) could be applied to the respiratory motor cortex to improve respiratory function. Little is known about the effect of rTMS on PCF in patients with supratentorial cerebral infarction during the subacute period. This study aimed to determine whether rTMS treatment could improve PCF in patients with supratentorial cerebral infarction. We retrospectively recruited patients with subacute supratentorial cerebral infarction who underwent a PCF test. The rTMS group received a combination of rTMS treatment for 2 weeks and conventional rehabilitation for 4 weeks. However, the control group underwent only conventional rehabilitation for 4 weeks. PCF tests were performed before and after treatment and the results were compared between the 2 groups. In total, 145 patients with supratentorial cerebral infarctions were recruited. The PCF parameters before and after treatment increased in both the rTMS and control groups. However, the rTMS group showed a greater increase in PCF values compared with the control group. In patients with supratentorial cerebral infarction, the combination of conventional rehabilitation and rTMS in the subacute period may be helpful in improving voluntary cough function compared with conventional rehabilitation alone.

A systematic review and meta-analysis of respiratory dysfunction in Parkinson's disease.

Respiratory dysfunction in Parkinson's disease (PD) is common and associated with increased hospital admission and mortality rates. Central and peripheral mechanisms have been proposed in PD. To date no systematic review identifies the extent and type of respiratory impairments in PD compared with healthy controls. PubMed, EMBASE, CINAHL, Web of Science, Pedro, MEDLINE, Cochrane Library and OpenGrey were searched from inception to December 2021 to identify case-control studies reporting respiratory measures in PD and matched controls. Thirty-nine studies met inclusion criteria, the majority with low risk of bias across Risk of Bias Assessment tool for Non-randomized Studies (RoBANS) domains. Data permitted pooled analysis for 26 distinct respiratory measures. High-to-moderate certainty evidence of impairment in PD was identified for vital capacity (standardised mean difference [SMD] 0.75; 95% CI 0.45-1.05; p < 0.00001; I2 =10%), total chest wall volume (SMD 0.38; 95% CI 0.09-0.68; p=0.01; I2 =0%), maximum inspiratory pressure (SMD 0.91; 95% CI 0.64-1.19; p < 0.00001; I2 =43%) and sniff nasal inspiratory pressure (SMD 0.58; 95% CI 0.30-0.87; p < 0.00001; I2 =0%). Sensitivity analysis provided high-moderate certainty evidence of impairment for forced vital capacity and forced expiratory volume in 1s during medication ON phases and increased respiratory rate during OFF phases. Lower certainty evidence identified impairments in PD for maximum expiratory pressure, tidal volume, maximum voluntary ventilation and peak cough flow. Strong evidence supports a restrictive pattern with inspiratory muscle weakness in PD compared with healthy controls. Limited data for central impairment were identified with inconclusive findings.