Peak Cough Flow Research Articles

Association Between Subglottic Pressure and Pulmonary Function in Individuals With Parkinson's Disease

In individuals with Parkinson's disease (PD), pulmonary complication such as weakness and rigidity of respiratory muscles and reduced cough airflow may be associated with reduced voice production due to limited pulmonary capacity and reduced airflow needed to vibrate the vocal folds. It is not clear, however, which pulmonary function parameter is determinant in the association with peak subglottic pressure (SGP). Therefore, the purpose of this study was to determine the association between peak SGP and pulmonary function parameters in individuals with PD. Forty-two individuals with diagnosis of idiopathic PD of both genders were recruited in the study. Mean and peak SGP, spirometric indices, maximum inspiratory pressure, maximum expiratory pressure (MEP), and peak cough flow (PCF) during reflex and voluntary cough were measured on all participants. The analysis revealed that peak SGP had a moderate but significant linear association with MEP (r = 0.38; P = 0.013), voluntary (r = 0.31; P = 0.051), and reflex PCF (r = 0.40; P = 0.012), but not with maximum inspiratory pressure (r = 0.23; P = 0.145). Higher values in peak SGP were associated with higher values in MEP, voluntary PCF, and reflex PCF. No linear association was detected between peak SGP and spirometric indices. Peak SGP has a direct association with voluntary and reflex PCF, and expiratory muscle strength, but not with inspiratory muscle strength. The association with peak SGP is higher for reflex PCF than for voluntary PCF.

Inspiratory muscle training in severe spinal muscular atrophy: a case report

Background/Aims Inspiratory muscle training aims to preserve or improve respiratory muscle strength in children with neuromuscular diseases in order to prevent or minimise pulmonary morbidity. The aim of this study was to determine the effect of inspiratory muscle training on clinical outcomes and health-related quality of life in a child with advanced neuromuscular disease and severe pulmonary restriction. Methods A one patient pre-test post-test study design was implemented. General function, spirometry, peak expiratory cough flow and health-related quality of life were measured at baseline and after a 6-week inspiratory muscle training programme. Inspiratory muscle strength (maximal inspiratory mouth pressure and sniff nasal inspiratory pressure) was measured every 2 weeks. The patient used a tapered flow threshold inspiratory training device (POWERbreathe K3) at an intensity of ± 30% of maximal inspiratory mouth pressure twice a day, 5 days per week. Findings The non-ambulatory 10-year-old girl with type 2 spinal muscular atrophy initially had a forced vital capacity of 18% predicted and peak expiratory cough flow of 60 litres/minute. A substantial improvement was seen in inspiratory muscle strength between baseline and 4 weeks. Patient health-related quality of life improved and patient satisfaction was high, with a score of 9/10. The patient developed a lower respiratory tract infection towards the end of the inspiratory muscle training period. No other adverse events occurred. Conclusions Improved inspiratory muscle strength and health-related quality of life was associated with inspiratory muscle training in a child with advanced spinal muscular atrophy. Controlled clinical trials are recommended to determine the safety and efficacy of inspiratory muscle training in children with advanced spinal muscular atrophy and severe respiratory muscle weakness to inform clinical practice.

Relationship of Cough Strength to Respiratory Function, Physical Performance, and Physical Activity in Older Adults.

Age- and lifestyle-related changes in respiratory and physical function affect cough strength. However, in older adults, the main factors that relate to cough strength remain unclear. This study was a preliminary investigation of factors that contribute to cough strength and the relationships between cough strength and respiratory function, physical performance, physical activity, and sedentary behavior in community-dwelling older adults. By using accelerometers and other tools, we assessed cough peak flow (CPF), FVC, maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax), chest and abdominal wall mobility (breathing movement scale), physical performance (Timed Up and Go test and 30-s chair stand test), physical activity (steps, and locomotive and non-locomotive moderate-to-vigorous physical activity), and sedentary behavior (sedentary time) in 65 community-dwelling older adults (25 males and 40 females) without air-flow limitation. Twenty-six percent of the subjects (17/65) had reduced CPF (<240 L/min). The subjects with reduced CPF had significantly lower FVC, PImax, PEmax, chest and abdominal wall mobility, physical performance, and locomotive moderate-to-vigorous physical activity compared with those with non-reduced CPF. Significant correlations between CPF and variables of respiratory function (FVC, PImax, PEmax, and breathing movement scale) and physical performance were weak to moderate. FVC and PImax were independently associated with CPF during the multiple regression analysis adjusted for sex, age, and height. The receiver operating characteristic analysis showed that FVC and PImax had fair-to-good sensitivity for detecting reduced CPF. Analysis of our results indicated that FVC and PImax were related to CPF and provided preliminary evidence that supported strategies for preserving and improving cough strength in community-dwelling older adults.

Analysis of motor and respiratory function in Duchenne muscular dystrophy patients

IntroductionDuchenne muscular dystrophy(DMD) shows motor and respiratory impairment. Methods19 DMD patients (DMDG) (nine ambulatory and 10 non-ambulatory) were evaluated through motor function measure (MFM), 6-minute walk test (6MWT), respiratory muscle strength, cough peak flow, spirometry and volumetric capnography (VCap) tools. Control group that performed spirometry and VCap (CG1-n = 17) were different from those that performed the 6MWT (CG2-n = 8). ResultsThe follow tools were assessed (p < 0.05): (i) MFM: Ambulatory patients showed higher values than non-ambulatory patients; (ii) 6MWT: DMDG walked a shorter distance and showed higher respiratory rate at rest and heart rate (HR) at rest than CG2; (iii) Spirometry: DMDG and non-ambulatory patients had minor values achieved in spirometry when compared with CG1 and ambulatory patients, respectively; (iv) VCap: DMDG when compared with CG1 showed: (<11 years-old) lower values in VCap parameters; (>11 years-old): higher HR and lower slope 2. There was correlation between spirometry, mainly for zFEV1/FVC, and MFM. ConclusionDMDG showed motor (MFM/6MWT) and respiratory (spirometry/VCap) deterioration when compared with CG. Non-ambulatory condition was associated with worse MFM and spirometry.

Factors Affecting Peak Cough Flow Value on Healthy Young Adults in Indonesia (Mongoloid)

Introduction: Cough is one of the main human defense mechanisms against respiratory tract infection and aspiration. Until now, there has not been any Peak Cough Flow (PCF) standard value in Indonesia. The preexisting standard PCF values were measured in Brazil (2012) and New Zealand (Caucasian). There were anthropometric differences based on race, which affect PCF. The aim of this study is to determine the PCF of healthy Indonesian adults and affecting factors.Methods: This study used crossectional in design. A number of 30 healthy adult subjects were recruited and analyzed. Chi-Square and multivariate analyses. Screening subjects was measured using spirometry test and cough ability using peak flow meter.Results: The mean PCF was 477.17 (L/min). There was significant correlation between gender (p=0.000), age (p=0.012;r=-0.430), and height (p=0.000;r=0.741) to PCF. Height was the most contributing variable (p=0.003;IK95% 2.37-10.77).Conclusion: The mean PCF in healthy adults was 477.17(L/min). Height was the most contributing factor, followed by age and gender.

A new treatment modality for the postoperative muscular pain management in pylorus preserving pancreaticoduodenectomy: a double-blind randomized control trial

Introduction: Pylorus preserving pancreaticoduodenectomy (PPPD) is a treatment for the resectable tumor or cancer in pancreaticoduodenal system. In open surgery, incision and suture of the abdominal muscles cause the inflammatory changes, strain, muscular pain which deteriorates the postoperative quality of life. We therefore suggest electrical twitch obtaining intramuscular stimulation (ETOIMS) as a new treatment modality for pain control after PPPD. Method: Between June 2018 and January 2019, among the patients who underwent PPPD in Department of Surgery, participated 45 patients were randomly assigned to two groups. The group 2 received ETOIMS right after surgery under the general anesthesia. ETOIMS was conducted on each patient using Clavis (Alpine Biomed ApS, Denmark). Aseptic monopolar needle electrode was inserted into the transverse abdominis muscle under ultrasound guidance. The pain score (visual analogue scale, VAS), peak cough flow (PCF), gait speed was compared with proportion to the preoperative values. The 3 main outcomes were analyzed by linear mixed model or repeated measures ANOVA using SPSS 23.0. Result: The pain score was highest on the day of surgery (Group 1: 6.5 ± 2.2, Group 2: 5.5±1.9, P = 0.17) and decreased gradually. Through the course of pain relieving, the pain scores were significantly lower in Group 2 after PPPD (P = 0.01). Although the PCF at each measuring time points didn’t show the group difference (P = 0.20), the improved PCF from the second day of surgery to discharge was greater in Group 2 (P = 0.02). Although the gait speeds at each time point were not significantly different, the time course of improving gait speed was significantly faster in Group 2 (P < 0.01). Conclusion: The ETOIMS is helpful in fast reducing postoperative somatic pain developed after PPPD, and also helpful in fast improvement of PCF and gait speed.

FACTORS ASSOCIATED WITH DIMINISHED COUGH INTENSITY IN COMMUNITY-DWELLING ELDERLY USING DAY CARE SERVICES: A PILOT STUDY

Purpose: We investigated factors affecting diminished cough intensity in community-dwelling elderly using day care services. Participants and Methods: A total of 61 elderly males and females aged ≥65 years who were certified to receive long-term adult day care services were enrolled in this study. Assessments included: Cough intensity (assessed using cough peak flow measurements, as well as possible determinants of cough intensity, lifestyle, and demographic characteristics), nutritional status (using the Mini Nutritional Assessment-Short Form), dietary intake (using the Dietary Variety Score), routine activity (using the Japanese version of the International Physical Activity Questionnaire), care-related factors (including day care services utilization and an oral exercise regimen) as well as age, need for long-term care, gender, sarcopenia status, the Charlson Comorbidity Index, and body mass, limb skeletal mass, and respiratory indices. Results: A reduced cough peak flow (odds ratio 4.46, 95% confidence interval: 1.08–18.43) was associated with sarcopenia and was weakly (not significantly) associated with age, gender, and the Mini Nutritional Assessment-Short Form score. Conclusion: A reduced cough peak flow was independently associated with sarcopenia and associated with age, gender, and nutritional status.

Cough Effectiveness, Functional Independence and Quality of Life of Stroke Survivors: A Cross-sectional Survey

Background: Stroke is associated with clinical spectrum of respiratory impairments, a significant one being aspiration pneumonia owing to failure to safeguard and clear the airway through coughing. Objectives: This research evaluated the correlation among cough effectiveness, functional independence, and quality of life of stroke survivors. Methods: This study involved 33 stroke survivors (13 males and 20 females) aged between 39-80 years. They were recruited from a teaching hospital in Nigeria. The participants were recruited between April and October, 2018. Cough effectiveness, functional independence (FI) and perception of quality of life (QoL) were assessed using Peak flow meter, Functional Independence Measure (FIM) and Stroke Specific Quality of Life Scale (SS-QoL) respectively. Spearman rank correlation coefficient was used to obtain the relationship between measured parameters. Level of significance was set at p&lt;0.05. Results: The mean peak cough flow (PCF) was 195.75±51.90 L/min for all the study participants. There was a positive significant correlation between cough effectiveness and motor subunit of FIM (rs=0.530, p=0.002) and overall FIM (rs=0.484, p=0.004). There was also a positive significant correlation between cough effectiveness and overall QoL score (rs=0.517, p=0.002). Five domains of QoL showed positive significant correlation to cough effectiveness; these include Mobility (rs=0.524, p=0.002), Self-care (rs=0.448, p=0.009), Social role (rs=0.487, p=0.004), Upper-limb function (rs=0.535, p=0.001), and Work and productivity (rs=0.556, p=0.001). Conclusion: Cough effectiveness is significantly positively correlated to functional independence and the QoL of stroke survivors.

Effects of mechanical inspiration and expiration exercise on velopharyngeal incompetence in subacute stroke patients.

To investigate the therapeutic effects of mechanical inspiration and expiration exercise using mechanical cough assist on velopharyngeal incompetence in patients with subacute stroke. Pilot, randomized controlled study. University-based rehabilitation centre. Thirty-six patients with subacute stroke diagnosed with velopharyngeal incompetence by videofluoroscopic swallowing study. Subjects were randomly assigned to 2 groups. The study group received conventional dysphagia therapy and additional mechanical inspiration and expiration exercise. The control group received conventional dysphagia therapy only. Swallowing function was evaluated according to the American Speech-Language-Hearing association scale, functional dysphagia score, and the penetration aspiration scale, based on the videofluoroscopic swallowing study. Coughing function was measured using peak cough flow. Eighteen patients in each group completed the protocol and were analysed. After treatment, the study group showed significant improvement in functional dysphagia score with regard to nasal penetration degree. Comparing the treatment effect between the 2 groups, nasal penetration degree and peak cough flow showed greater improvement in the study group. Mechanical inspiration and expiration exercise had a therapeutic effect on velopharyngeal incompetence in subacute stroke patients with dysphagia. This therapy is easy to provide clinically and could be a useful therapeutic strategy for velo-pharyngeal incompetence with dysphagia in patients with stroke.

Effect of air stacking training on pulmonary function, respiratory strength and peak cough flow in persons with cervical spinal cord injury

Objective: This study investigated the effects of air stacking training (AST) on pulmonary function, respiratory strength, and peak cough flow (PCF)...

Improvement of Peak Cough Flow After the Application of a Mechanical In-exsufflator in Patients With Neuromuscular Disease and Pneumonia: A Pilot Study.

ObjectiveTo investigate and demonstrate persistent increase of peak cough flow after mechanical in-exsufflator application, in patients with neuromuscular diseases and pneumonia.MethodsA mechanical in-exsufflator was applied with patients in an upright or semi-upright sitting position (pressure setting, +40 and −40 cmH2O; in-exsufflation times, 2–3 and 1–2 seconds, respectively). Patients underwent five cycles, with 20–30 second intervals to prevent hyperventilation. Peak cough flow without and with assistive maneuvers, was evaluated before, and 15 and 45 minutes after mechanical in-exsufflator application.ResultsPeak cough flow was 92.6 L/min at baseline, and 100.4 and 100.7 L/min at 15 and 45 minutes after mechanical in-exsufflator application, respectively. Assisted peak cough flow at baseline, 15 minutes, and 45 minutes after mechanical in-exsufflator application was 170.7, 179.3, and 184.1 L/min, respectively. While peak cough flow and assisted peak cough flow increased significantly at 15 minutes after mechanical in-exsufflator application compared with baseline (p=0.030 and p=0.016), no statistical difference was observed between 15 and 45 minutes.ConclusionIncreased peak cough flow after mechanical in-exsufflator application persists for at least 45 minutes.

Clinical Importance of Peak Cough Flow in Dysphagia Evaluation of Patients Diagnosed With Ischemic Stroke.

ObjectiveTo investigate the relationship between peak cough flow (PCF), pulmonary function tests (PFT), and severity of dysphagia in patients with ischemic stroke.MethodsThis study included patients diagnosed with ischemic stroke, who underwent videofluoroscopic swallowing study (VFSS), PCF and PFT from March 2016 to February 2017. The dysphagia severity was assessed using the videofluoroscopic dysphagia scale (VDS). Correlation analysis of VDS, PFT and PCF was performed. Patients were divided into three groups based on VDS score. One-way ANOVA of VDS was performed to analyze PCF, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and age among the different groups.ResultsThe correlation coefficients of VDS and PCF, VDS and FVC, and VDS and FEV1 were -0.836, -0.508, and -0.430, respectively, all of which were statistically significant at the level of p<0.001. The one-way ANOVA indicated statistically significant differences in PCF, FVC, FEV1, and age among the VDS groups. Statistically significant differences in VDS and age were observed between aspiration pneumoia and non-aspiration pneumonia groups.ConclusionCoughing is a useful factor in evaluating the risk of aspiration in dysphagia patients. Evaluation of respiratory and coughing function should be conducted during the swallowing assessment of patients with ischemic stroke.

Titration of Mechanical Insufflation–Exsufflation Optimal Pressure Combinations in Neuromuscular Diseases by Flow/Pressure Waveform Analysis

IntroductionThe aim of this study was to assess several air-pressure settings for MI–E to determine their effect on peak cough flow (PCF), and to compare the best pressures with those are more common used in the literature (±40cmH2O) in patients with neuromuscular disorders (NMD). MethodsAdults with NMD in whom MI–E was indicated were recruited. Assisted PCF was measured by an external pneumotachograph. The protocol included 9 PCF measures per patient: 1 baseline (non-assisted), 4 with increasing inspiratory pressures without negative pressure (10, 20, 30 and 40cmH2O or maximum tolerated), and then 4 adding expiratory pressures (−10, −20, −30 and −40cmH2O or maximum tolerated) with maximum inspiratory pressure previously achieved. ResultsTwenty one patients were included, 61% with amyotrophic lateral sclerosis (ALS). Mean PCFs with recommended pressures (±40cmH2O) were lower than the scored in the individualized steps of the titration protocol (197.7±67l/min vs 214.2±60l/min, p<0.05). Regarding subgroups, mean PCFmax values in ALS patients with bulbar symptoms were significantly higher than those achieved with recommended pressures (163.6±80 vs 189±66l/min, p<0.05). ConclusionThe PCFmax obtained with the protocol did not always match the recommended settings. It may be advisable to perform MI–E titration assessed by non-invasive PCF monitoring in patients with NMD, especially in ALS with bulbar involvement to improve the therapy detecting airway collapse induced by high pressures.

Posture and firmness changes in a pressure-relieving air mattress affect cough strength in elderly people with dysphagia.

Dysphagia is the major pathophysiologic mechanism leading to aspiration pneumonia in the elderly. Elderly people with dysphagia who show low levels of the cough peak flow (CPF) are at greater risk for aspiration pneumonia. It has been reported that CPF values were significantly lower in the “soft” versus “hard” mode of a pressure-relieving air mattress in healthy volunteers in a supine position. Parameters such as spinal curvature, however, were not evaluated in detail. In this study, we clarified whether the changes in posture associated with two different firmness levels of a pressure-relieving air mattress were associated with cough production and related factors in the elderly with dysphagia. The body sinking distance, pelvic tilt angle, and immersion of the lumbar spine were measured to evaluate changes in posture. Forty subjects met the study criteria for dysphagia. The “soft” mode showed significantly lower CPF values than the “hard” mode (soft 274.9 ± 107.2 L/min vs. hard 325.0 ± 99.5 L/min, MD 50.0 95%CI 33.1–66.9 P < 0.001). Values of forced vital capacity (FVC) and maximal inspiratory pressure (PImax) were significantly lower in the “soft” mode than in the “hard” mode (MD 0.10 95%CI 0.04–0.17, P = 0.002, MD 3.2 95%CI 0.9–5.5, P = 0.007, respectively). Although there was no significant difference between the two firmness levels, maximal expiratory pressure (PEmax) values also tended to be lower in the “soft” than in the “hard” mode, (MD 2.9 95%CI -0.6–6.3 P = 0.1). At both firmness levels, CPF values were significantly correlated with FVC, PImax, and PEmax. The difference in sinking distance in the anterior superior iliac spine was significantly larger than that in the lesser tubercle of the humerus and patella. Additionally, in the soft mode, the pelvic tilt angle and contact area around the lumbar spine were significantly larger than those observed in the “hard” mode. Parameters associated with the production of cough, including inspiratory muscle strength, lung volume, and ultimately CPF, may be affected by immersion of the lumbar spine and curvature of the spine that results from the “soft” mode in elderly patients with dysphagia.

Cough peak flow decline rate predicts survival in patients with amyotrophic lateral sclerosis.

In this study we investigated the prognostic significance of cough peak flow (CPF) decline rate in patients with amyotrophic lateral sclerosis (ALS). Thirty-four patients with ALS participated in our investigation. We examined CPF, forced vital capacity (FVC), body mass index, and the revised ALS Functional Rating Scale (ALSFRS-R), and followed patients to death, tracheostomy, or non-invasive ventilator dependency. We analyzed the relationship between the rate of decline of each parameter and survival prognosis. The CPF decline rate significantly correlated with the decline rates of the ALSFRS-R bulbar score (P < 0.0001) and FVC (P < 0.0001). Patients with a CPF decline rate ≥25% had shorter overall survival (P < 0.0001). Cox model multivariate analyses showed that the CPF decline rate was an independent prognostic factor for survival (P = 0.021). The CPF decline rate reflects the progression of bulbar and respiratory dysfunction and predicts survival. Muscle Nerve 59:168-173, 2019.

The Safety and Efficacy of Expiratory Muscle Strength Training for Rehabilitation After Supracricoid Partial Laryngectomy: A Pilot Investigation.

Expiratory muscle strength training (EMST) is a safe, effective intervention that can be performed at home and may be beneficial for individuals with voice and swallowing disorders. To date there have been few studies of EMST in the head and neck cancer population, and there are no previous reports of its use after supracricoid partial laryngectomy (SCPL). The current prospective clinical pilot study was undertaken to determine the safety and efficacy of a 4-week treatment program. Six participants were recruited who had previously undergone SCPL, were medically stable, and had no contraindications for use of the device. At baseline, objective respiratory measurements were collected, dietary status was recorded, and participants were asked to complete a series of validated self-report instruments relating to voice, swallowing, breathing, and cough. Following the completion of treatment, baseline measures were repeated, and participant feedback was solicited. The majority of individuals found the device easy to use (83%) and beneficial (83%). The side effects of treatment were relatively minor and included dizziness, muscle inflammation, and vocal fatigue. There were improvements in 2 measures from before to after treatment, namely, an average 21% increase in peak cough flow (from 371.67 to 451.33 L/min) and a 38% decrease on the Dyspnea Index (from 6.17 to 3.83). Other measures showed inconsistent changes. EMST appeared to improve cough strength and reduce dyspnea symptoms after SCPL. Further study of the relative efficacy of EMST compared to other rehabilitation protocols after SCPL is needed.

Cough augmentation techniques for people with chronic neuromuscular disorders

Background People with neuromuscular disorders may have a weak, ineffective cough predisposing them to respiratory complications. Cough augmentation techniques aim to improve cough effectiveness and mucous clearance, reduce the frequency and duration of respiratory infections requiring hospital admission, and improve quality of life. Objectives To determine the efficacy and safety of cough augmentation techniques in adults and children with chronic neuromuscular disorders. Search methods On 13 April 2020, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and ClinicalTrials.gov for randomised controlled trials (RCTs), quasi-RCTs, and randomised cross-over trials. Selection criteria We included trials of cough augmentation techniques compared to no treatment, alternative techniques, or combinations thereof, in adults and children with chronic neuromuscular disorders. Data collection and analysis Two review authors independently assessed trial eligibility, extracted data, and assessed risk of bias. The primary outcomes were the number and duration of unscheduled hospitalisations for acute respiratory exacerbations. We assessed the certainty of evidence using GRADE. Main results The review included 11 studies involving 287 adults and children, aged three to 73 years. Inadequately reported cross-over studies and the limited additional information provided by authors severely restricted the number of analyses that could be performed. Studies compared manually assisted cough, mechanical insufflation, manual and mechanical breathstacking, mechanical insufflation-exsufflation, glossopharyngeal breathing, and combination techniques to unassisted cough and alternative or sham interventions. None of the included studies reported on the primary outcomes of this review (number and duration of unscheduled hospital admissions) or listed 'adverse events' as primary or secondary outcome measures. The evidence suggests that a range of cough augmentation techniques may increase peak cough flow compared to unassisted cough (199 participants, 8 RCTs), but the evidence is very uncertain. There may be little to no difference in peak cough flow outcomes between alternative cough augmentation techniques (216 participants, 9 RCTs). There was insufficient evidence to determine the effect of interventions on measures of gaseous exchange, pulmonary function, quality of life, general function, or participant preference and satisfaction. Authors' conclusions We are very uncertain about the safety and efficacy of cough augmentation techniques in adults and children with chronic neuromuscular disorders and further studies are needed.

A Mobile Cough Strength Evaluation Device Using Cough Sounds.

Although cough peak flow (CPF) is an important measurement for evaluating the risk of cough dysfunction, some patients cannot use conventional measurement instruments, such as spirometers, because of the configurational burden of the instruments. Therefore, we previously developed a cough strength estimation method using cough sounds based on a simple acoustic and aerodynamic model. However, the previous model did not consider age or have a user interface for practical application. This study clarifies the cough strength prediction accuracy using an improved model in young and elderly participants. Additionally, a user interface for mobile devices was developed to record cough sounds and estimate cough strength using the proposed method. We then performed experiments on 33 young participants (21.3 ± 0.4 years) and 25 elderly participants (80.4 ± 6.1 years) to test the effect of age on the CPF estimation accuracy. The percentage error between the measured and estimated CPFs was approximately 6.19%. In addition, among the elderly participants, the current model improved the estimation accuracy of the previous model by a percentage error of approximately 6.5% (p < 0.001). Furthermore, Bland-Altman analysis demonstrated no systematic error between the measured and estimated CPFs. These results suggest that the developed device can be applied for daily CPF measurements in clinical practice.

CFD Simulation of Airflow Dynamics During Cough Based on CT-Scanned Respiratory Airway Geometries

The airflow dynamics observed during a cough process in a CT-scanned respiratory airway model were numerically analyzed using the computational fluid dynamics (CFD) method. The model and methodology were validated by a comparison with published experimental results. The influence of the cough peak flow rate on airflow dynamics and flow distribution was studied. The maximum velocity, wall pressure, and wall shear stress increased linearly as the cough peak flow increased. However, the cough peak flow rate had little influence on the flow distribution of the left and right main bronchi during the cough process. This article focuses on the mathematical and numerical modelling for human cough process in bioengineering.

Functional and Endoscopic Indicators for Percutaneous Endoscopic Gastrostomy (PEG) in Amyotrophic Lateral Sclerosis Patients.

(1) Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative condition, whose bulbar involvement compromises language, swallowing, and airway protection. When oral nutrition is no longer adequate, percutaneous endoscopic gastroscopy (PEG) may be indicated. However, as exact timing is still debatable, we tried to find it. (2) Methods: A prospective cohort study was performed using fiber-optic endoscopic evaluation of swallowing (FEES), functional evaluation scales (ALS Functional Rating Scale-Revised (ALSFRS-R) and bulbar sub-score (ALSFRS-R-B)), lung function tests (like Forced Vital Capacity (FVC), Cough Peak Flow (CPF)) and anthropometric data. (3) Results: Twenty-three patients were enrolled (mean 65.4 ± 9.1 years, 60.9% males), 12 with spinal-onset. During the study period, 58 FEES were performed (1–4/patients). Even before formal PEG indication, suggestions were given to correct the alterations found. PEG was placed in 12 patients, on average 21.8 months after diagnosis (FVC = 69.9% ± 26.7%, ALSFRS-R-B = 7.7 ± 3.7, ALSFRS-R = 28.9 ± 12.3), and being 91.7% under ventilatory support. ALSFRS-R-B, CPF, FVC, and ALSFRS-R showed significant discriminant ability for PEG placement. Sensitivity and specificity were, respectively, ALSFRS-R-B ≤ 8 (100/90.9), CPF ≤ 205 (83.3), FVC ≤ 74 (83.3/74.2), and ALSFRS-R < 29 (83.3/65.1). (4) Conclusions: FEES provide additional information beyond formal PEG indication. ALSFRS-R-B score ≤ 8 was found as a best functional and noninvasive indicator for PEG placement in ALS patients.