Peak Cough Flow Values Research Articles

Dyspnea, respiratory muscle strength, cough capacity, and sleep quality in individuals with substance use disorder

There is evidence that substance use and smoking cause some adverse effects on the respiratory system. The aim of this study was to assess dyspnea severity, respiratory muscle strength, cough capacity, and sleep quality in people with substance use disorder (SUD). Forty eight individuals with SUD and 28 active cigarette smokers participated in the study. Participants’ dyspnea severity was assessed using the Modified Medical Research Council Scale, respiratory muscle strength was measured with a portable electronic mouth pressure device, peak cough flow was assessed with a Peak Flow Meter, and sleep quality was determined using the Pittsburgh Sleep Quality Index (PSQI). The amount of daily cigarette smoking and dyspnea severity were significantly higher in individuals with SUD (p < .001). Peak cough flow values, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), MIP (%predicted), and MEP (%predicted) were not significantly different between the SUD patients and the active cigarette smokers (p > .05). However, PSQI sub-parameters such as subjective sleep quality, sleep latency, habitual sleep efficiency, use of sleeping medication, and total scores showed significant differences between the SUD patients and the active cigarette smokers (p < .05, p < .001, p = .03, p < .001, p < .001, respectively). Individuals with SUD were found to have higher dyspnea and poorer sleep quality than active smokers. However, respiratory muscle strength and cough capacities were similar.

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.

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.

Pulmonary function tests for evaluating the severity of Duchenne muscular dystrophy disease.

In Duchenne muscular dystrophy (DMD), lung disease contributes significantly to morbidity and mortality. This study aimed to assess the usefulness of various pulmonary function tests in evaluating DMD severity. This retrospective study analysed lung function tests of patients with DMD-treated in the multidisciplinary respiratory neuromuscular clinic at Schneiders' Children Medical Center of Israel. Data were analysed according to age, ambulatory status and glucocorticoid treatment. Among 90 patients with DMD, 40/63 (63.5%) ambulatory patients and 22/27 (81.5%) nonambulatory patients successfully performed spirometry. Significant annual declines were demonstrated among nonambulatory patients, in percentile predicted forced vital capacity (3.8%) and in total lung capacity (5.5%) per year. The decline correlated with age and loss of ambulation but not with steroid treatment. Peak cough flow values were randomly distributed and did not correlate with age, ambulation or treatment. In nonambulatory patients, transcutaneous carbon dioxide measurement correlated significantly with age (r=0.55, p=0.02). Forced vital capacity, total lung capacity and transcutaneous carbon dioxide correlated with the clinical severity of disease in children with DMD. These measures may be useful in follow-up and clinical trials. A comparable correlation was not found for peak cough flow.

Effects of Rehabilitative Intervention for Augmenting Cough Function in Patients with Multiple System Atrophy.

One of the causes of death in patients with multiple system atrophy (MSA) is aspiration pneumonia caused by cough dysfunction. This study aimed to identify an effective approach to improve coughing and to explore the establishment of criteria for the use of gastrostomy based on cough and respiratory dysfunctions. Eighteen probable MSA patients participated in the study. They were categorized into air stacking and non-air stacking groups. First, we investigated how the inspiration volume changes by applying maximum insufflation capacity (MIC). Second, peak cough flow (PCF) was measured by different cough augmentation methods: 1) spontaneous coughing (SpC); 2) SpC with MIC (SpC + MIC); 3) SpC with manually assisted cough (MAC) (SpC + MAC); and 4) SpC with MIC and MAC (SpC + MIC + MAC). Among these four conditions, PCF values were compared to determine the most effective approach for cough augmentation. Receiver operating characteristic analysis was performed on percent forced vital capacity (%FVC) to determine an index for discriminating PCF below160 L/min, which indicates a high risk of suffocation, involving SpC and SpC + MIC. Inspiration volume increased significantly with MIC in both groups (P < 0.05), and PCF increased significantly with MIC in the air stacking group (P < 0.01). PCF could not be maintained at 160 L/min when %FVC fell below 59%, even when MIC was applied. PCF increases with MIC in patients with MSA. It may be meaningful to consider the timing of gastrostomy introduction based on the severity of cough and respiratory dysfunction.

Utilizing Pulmonary Function Parameters to Predict Dysphagia in Individuals With Cervical Spinal Cord Injuries.

Objective To utilize pulmonary function parameters as predictive factors for dysphagia in individuals with cervical spinal cord injuries (CSCIs).MethodsMedical records of 78 individuals with CSCIs were retrospectively reviewed. The pulmonary function was evaluated using spirometry and peak flow meter, whereas the swallowing function was assessed using a videofluoroscopic swallowing study. Participants were divided into the non-penetration-aspiration group (score 1 on the Penetration-Aspiration Scale [PAS]) and penetration-aspiration group (scores 2–8 on the PAS). Individuals with pharyngeal residue grade scores >1 were included in the pharyngeal residue group.ResultsThe mean age was significantly higher in the penetration-aspiration and pharyngeal residue groups. In this study, individuals with clinical features, such as advanced age, history of tracheostomy, anterior surgical approach, and higher neurological level of injury, had significantly more penetration-aspiration or pharyngeal residue. Individuals in the penetration-aspiration group had significantly lower peak cough flow (PCF) levels. Individuals in the pharyngeal residue group had a significantly lower forced expiratory volume in 1 second (FEV1). According to the receiver operating characteristic curve analysis of PCF and FEV1 on the PAS, the cutoff value was 140 L/min and 37.5% of the predicted value, respectively.ConclusionLow PCF and FEV1 values may predict the risk of dysphagia in individuals with CSCIs. In these individuals, active evaluation of swallowing is recommended to confirm dysphagia.

Lung volume recruitment improves volitional airway clearance in amyotrophic lateral sclerosis.

Introduction/AimsIn this study we evaluated the effects of lung volume recruitment treatment (LVR), a low‐tech, low‐cost, manual “breath‐stacking” technique used to help people cough with enough force to clear their airways, thereby reducing the risk of aspiration and choking, on five volitional airway clearance and protection behaviors used by people living with amyotrophic lateral sclerosis (PwALS).MethodsUsing a repeated‐measures cross‐over design, 29 PwALS performed five volitional airway clearance and protection behaviors in LVR treatment and in no‐treatment, control conditions. Peak cough flow (PCF) was used to measure maximum expiratory rate during forced expiration, throat clearing, hawking, post‐swallow coughing, and the supraglottic swallowing maneuver. Comparisons were made as a function of condition (treatment or control) and three time‐points (pretreatment, and 15 and 30 minutes posttreatment).ResultsLVR treatment had a significant positive effect on maximum expiratory rates during all tested airway clearance and protection behaviors. Increased PCF values lasted for up to 30 minutes post‐LVR for all tested behaviors in the treatment condition.DiscussionWe found that LVR treatment could increase control over airway clearance in PwALS, as well as provide improved airway protection for up to 30 minutes, the duration of a typical meal. This study has implications for patient care. These include offering patients control over some of the most feared symptoms of ALS, particularly choking during activities of daily living, and enhanced ALS respiratory care in low‐resource settings. Findings may have implications for other neurodegenerative disorders in which dysphagia occurs with retained sensory function.

Value of Peak Cough Flow (PCF) in Healthy Middle Adulthood and Late Adulthood and the Affecting Factors

ABSTRACTIntroduction: Cough is a symptom that is felt by all humans and it is important for the protection which maintains mucus secretion, foreign substances, and infections of the larynx, trachea and bronchi. Thepurpose of this study is to find out the PCF value in healthy middle adulthood and late adulthood and the factors that influence it.Methods: This study is a cross-sectional study involving 99 subjects. Subjects were patients in the clinic for medical rehabilitation of middle adulthood and late adulthood healthy respiration. Subjects whofulfilled the inclusion and exclusion criteria were examined with spirometry to ensure healthy respiration and after that, the PCF examination was carried out with a peakflowmeter device and the correlation wasobserved with age, gender and, height.&#x0D; Results: The PCF value in healthy middle adulthood is 190-540 L / minute (41-50 years 465 L / minute, ages 51-60 years 405 L / minute) and healthy late adulthood is 245-520 L / minute with median 352.5L / minute. Men have a greater PCF value than women, but at the age of 61 years and over there not significantly different. The higher age, the lower the PCF value obtained and there was a statisticallysignificant decrease in the PCF value at 61-70 years of age compared to 41-50 years of age. Subjects with high height have a tendency for a lar ger PCF value and height will af fect the PCF value.&#x0D; Conclusion: Obtained PCF values in middle adulthood and late adulthood with healthy respiration and there is a relationship between sex, age and height factors for the PCF value.&#x0D; Keywords: Age, height, Peak Cough Flow, peakflow meter, sex.

Cut-off Values of the Respiratory Muscle Power and Peak Cough Flow in Post-Stroke Dysphagia.

Background and objectives: This study aimed to determine the cut-off values of the following three respiratory pressure meters; the voluntary peak cough flow (PCF), maximal expiratory pressure (MEP) and maximal inspiratory pressure (MIP); associated with post-stroke dysphagia and assess which of these parameters show good diagnostic properties associated with post-stroke dysphagia. Materials and Methods: Retrospective analysis of a prospectively maintained database. Records of patients with first-ever diagnosed dysphagia attributable to cerebrovascular disease, who had performed spirometry measurements for the PCF, MIP and MEP. Results: From a total of 237 stroke patients, 163 patients were diagnosed with dysphagia. Those with dysphagia had significantly lower PCF values than those without dysphagia (116.3 ± 75.3 vs. 219.4 ± 91.8 L/min, p < 0.001). In addition, the former group also had lower MIP (30.5 ± 24.7 vs. 41.6 ± 25.7 cmH2O, p = 0.0002) and MEP (41.0 ± 27.9 vs. 62.8 ± 32.3 cmH2O, p < 0.001) values than the latter group. The receiver operating characteristic curve analysis showed that the PCF cut-off value of 151 L/min (area under the receiver operating characteristic curve [AUC] 0.81; sensitivity 72%; specificity 78.8%) was associated with post-stroke dysphagia. The optimum MEP and MIP cut-off were 38 cmH2O (AUC 0.70, sensitivity 58%; specificity 77.7%) and 20 cmH2O (AUC 0.65, sensitivity 49%; specificity 84%). PCF showed the highest AUC results. Results from the univariate analysis indicated that PCF values of ≤151 L/min increased risk of dysphagia by 9.51-fold (4.96–18.23). Multivariable analysis showed that after controlling of other clinical factor, the PCFs at this cut-off value still showed increased risk of by 4.19 (2.02–83.69) but this was not observed with the MIPs or MEPs. Conclusions: Our study has provided cut-off values that are associated with increased risk of dysphagia. Among the three parameters, PCF showed increased association with post-stroke dysphagia.

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.

Peak Cough Flow in Children with Neuromuscular Disorders.

Patients with neuromuscular disease (NMD) experience weakened cough due to progressive respiratory muscle weakness. Peak cough flow (PCF) measurements derived from adult populations are used to recommend initiation of assisted cough therapies. The objective of this study was to characterize PCF values among pediatric patients with NMD. Retrospective chart review was performed for patients seen in the multidisciplinary pediatric muscular dystrophy clinic from 2010 to 2016. Clinical and demographic variables included age, gender, ambulation status, and PCF measurements. 366 patients with an established diagnosis of NMD (median age 11.8years) were included in this study. 102 (27.8%) out of the 366 patients were affected by Duchenne muscular dystrophy (DMD), 42 (11.5%) by congenital muscular dystrophy (CMD), 42 (11.5%) by Charcot Marie Tooth disease (CMT) and 24 (6.5%) by Becker's muscular dystrophy (BMD). The mean PCF values in DMD (255.8L/min) and CMD (249.1L/min) were lower than CMT (321.5L/min) with p-values of 0.007 and 0.02, respectively. The mean PCF of BMD (333.3L/min) was higher than that of DMD and CMD but the difference was not statistically significant. PCFs were not statistically different between ambulatory and non-ambulatory status (263.0L/min versus 290.8L/min, p = 0.12). Children under 10years of age had lower PCF relative to older subjects (179.5L/min versus 300.9L/min, p < 0.0001). Baseline PCF values in young children are below the adult-specific values suggested for starting assisted cough techniques. Further longitudinal trials are required to derive pediatric-specific reference values for PCF in patients with NMD.

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 novel reflex cough testing device

BackgroundThe reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia.MethodsThis device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer.The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group).ResultsWith the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p < 0.0001), while that of group B was significantly lower than that of the control group (p < 0.0001). The time until the cough reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p < 0.001, B: p < 0.001), but there was no significant difference between groups A and B (p = 0.0907).ConclusionOur newly developed device can easily and simultaneously measure the time until the cough reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.

Accuracy of portable devices in measuring peak cough flow

Peak cough flow (PCF) measurements can be used as indicators of cough effectiveness. Portable peak flow meters and spirometers have been used to measure PCF, but little is known about their accuracy compared to pneumotachograph systems. The aim of this study was to compare the accuracy of four portable devices (Mini–Wright and Assess peak flow meters, SpiroUSB and Microlab spirometers) in measuring PCF with a calibrated laboratory based pneumotachograph system. Twenty healthy volunteers (mean (SD) age 45 (16) years) coughed through a pneumotachograph connected in series with each portable device in turn, and the differences in PCF readings were analysed. In addition, mechanically generated flow waves of constant peak flow were delivered through each device both independently and when connected in series with the pneumotachograph. Agreement between PCF readings obtained with the pneumotachograph and the portable devices was poor. Peak flow readings were on average lower by approximately 50 L min−1 when measured using the portable devices; 95% limits of agreement spanned approximately 150 L min−1. The findings highlight the potential for inaccuracy when using portable devices for the measurement of PCF. Depending on the measurement instrument used, absolute values of PCF reported in the literature may not be directly comparable.

Comparison of Three Cough-Augmentation Techniques in Neuromuscular Patients: Mechanical Insufflation Combined with Manually Assisted Cough, Insufflation-Exsufflation Alone and Insufflation-Exsufflation Combined with Manually Assisted Cough

Background: Mechanical insufflation-exsufflation (MI-E), more commonly known as ‘cough assist therapy', is a method which produces inspiratory and expiratory assistance to improve cough performances. However, other alternatives or combinations are possible. Objective: The objective was to compare the effects of mechanical insufflation combined with manually assisted coughing (MAC), insufflation-exsufflation alone and insufflation-exsufflation combined with MAC in neuromuscular patients requiring cough assistance. Methods: Eighteen neuromuscular patients with severe respiratory muscle dysfunction and peak cough flow (PCF) lower than 3 liters/s or maximal expiratory pressure (MEP) lower than +45 cm H₂O were studied. Patients were studied under three cough-assisted conditions, which were used in random order: insufflation by intermittent positive-pressure breathing (IPPB) combined with MAC, MI-E and MI-E + MAC. Results: Overall, PCF was higher with IPPB + MAC than with MI-E + MAC or MI-E alone. Among the 12 patients who had higher PCF values with IPPB + MAC than with the two other techniques, 9 exhibited mask pressure swings during MI-E exsufflation, with a transient positive-pressure value due to the expiratory flow produced by the combined patient cough effort and MAC. Each of these 9 patients had higher PCF values (>5 liters/s) than did the other 9 patients when using IPPB + MAC. Conclusion: Our results indicate that adding the MI-E device to MAC is unhelpful in patients whose PCF with an insufflation technique and MAC exceeds 5 liters/s. This is because the expiratory flow produced by the patient's effort and MAC transitorily exceeds the vacuum capacity of the MI-E device, which therefore becomes a transient load against the PCF.

Use of air stacking and abdominal compression for cough assistance in people with complete tetraplegia

Cross-sectional. To assess cough using air stacking (AS) to assist inspiratory volume with abdominal compression (AC) during expiration in patients with American Spinal Injury Association Impairment Scale (AIS) A. Large tertiary hospital in Chile. Peak cough flow (PCF) was measured during four different interventions: spontaneous maximal expiratory effort (MEE); MEE while receiving AC (MEE-AC); MEE after AS with a manual resuscitation bag (AS-MEE); and MEE with AS and AC (AS-MEE-AC). Fifteen in-patients with complete tetraplegia (C4-C6) were included. Median age was 33 years (16-56). PCF during the different interventions was PCF for MEE was 183±90 l min(-1); PCF for MEE-AC was 273±119 l min(-1); PCF for AS-MEE was 278±106 l min(-1) and PCF for AS-MEE-AC was 368±129 l min(-1). We observed significant differences in PCF while applying MEE-AC and AS-MEE compared with MEE (P=0.0001). However, the difference in PCF value was greater using the AS-MEE-AC technique (P=0.00001). Patients with spinal cord injury (SCI) presented an ineffective cough that constitutes a risk factor for developing respiratory complications. The application of combined techniques (AS-MEE-AC) can reach near normal PCF values. This is a low-cost, simple and easily applied intervention that could be introduced to all patients with tetraplegia.

Evaluation of peak cough flow in Brazilian healthy adults

IntroductionIn this study we aimed to evaluate the peak cough flow (PCF) in healthy Brazilian subjects.MethodsWe evaluated 484 healthy subjects between 18 and 40 years old. Subjects were seated and oriented were asked to perform a maximal inspiration followed by a quick, short and explosive expiration on the peak flow meter. Three measures were carried out and recorded the average of the three results for each individual.ResultsThe PCF values ranged between 240 and 500 L/min. The PCF values were lower in females than in males. The PCF was inversely proportional to age.ConclusionThe values for Brazilian adult healthy subjects regarding PCF were between 240 and 500 L/min.

Relação entre força de tosse e nível funcional em um grupo de idosos

Respiratory muscle strength is influenced by aging. To assess, in a healthy elderly population, the influence of physical activity and functional performance on the pulmonary function parameters, on respiratory muscle strength and on coughing. Observation study that sixty one elderly with age equal or more than 60 years (72.3 ± 7.2 years), with normal spirometry were included. Maximal Inspiratory Pressure (MIP), Maximal Expiratory Pressure (MEP), Peak Expiratory Flow (PEF), Peak Cough Flow (PCF) and Human Activity Profile (HAP) were evaluated. The elderly were separated in two groups (active and moderately active) according to HAP. Student`s test was used for univariate analysis and regression analysis models was used for multivariate analysis. Elderly participants who were classified as active presented on average 13.5 cmH₂O higher MEP (88 ± 21.4 cmH₂O), and 16.2 cmH₂O higher MIP (76 ± 17.7 cmH₂O). Maximal respiratory pressure decreases 1 cmH₂O per year. The PEF and PCF were higher for male (p < 0.001) and active elderly (p = 0.046 e p = 0.004 respectively). A positive correlation was observed between HAP and the following variables: MEP MIP and PCF (r = 0.527, p < 0.001; r = 0.498, p < 0.001 and r = 0.365, p = 0.004, respectively). The active life style can positively affect the respiratory muscle strength and PCF values. Aging is associated to respiratory muscle strength reduction (both inspiratory and expiratory). Women showed lower PEmax.

Effect of Long-term Steroids on Cough Efficiency and Respiratory Muscle Strength in Patients With Duchenne Muscular Dystrophy

The objective of this study was to determine whether long-term steroid therapy is associated with increased peak cough flow in patients with Duchenne muscular dystrophy and to determine which pulmonary function test variable is most predictive of peak cough flow. In this case-control study, the medical charts of patients who had Duchenne muscular dystrophy and had pulmonary function tests at our institution in the previous 2 years were examined. Steroid-treated patients were on therapy for at least 1 year. The measured pulmonary function tests included forced vital capacity, maximum expiratory pressure, maximum inspiratory pressure, maximum voluntary ventilation, and peak cough flow. Multiple linear regression analysis was used to determine which pulmonary function test measure was most predictive of peak cough flow and assess the influence of steroid treatment and patient age on peak cough flow. Ten steroid-treated and 25 untreated patients were analyzed. Peak cough flow and maximum expiratory pressure were significantly higher in the steroid-treated patients. Each of the pulmonary function test variables was significantly associated with peak cough flow. The linear model that had the highest adjusted r2 value included only 2 variables: maximum voluntary ventilation and steroid treatment, demonstrating that steroid-treated patients had peak cough flow values that were 27 L/min higher than the untreated patients. The interaction between maximum voluntary ventilation and steroid was not statistically significant, suggesting that the steroid-associated increase in peak cough flow was approximately constant over the observed range of maximum voluntary ventilation values. The effects of maximum voluntary ventilation and treatment group on peak cough flow were not confounded with the patient age. Long-term steroid therapy is associated with improved peak cough flow and respiratory muscle strength in patients with Duchenne muscular dystrophy. Maximum voluntary ventilation may be a useful predictor of lung function in Duchenne muscular dystrophy.

Systematic review of techniques to enhance peak cough flow and maintain vital capacity in neuromuscular disease: the case for mechanical insufflation–exsufflation

Patients with neuromuscular disease risk developing chest infections due to the inability to cough effectively and to maintain adequate lung volume. This systematic review aimed to evaluate the comparative effectiveness of techniques used in the respiratory management of these patients. Articles evaluating peak cough flow measurements and maintenance of lung volumes only were selected to retain a specific focus for comparison. A database search was performed using the Cochrane controlled register, AMED, Cinahl, Medline and PEDro. Various techniques improved cough efficacy in neuromuscular disease by increasing peak cough flow values and maintaining lung volume. Mechanical insufflation–exsufflation is a technique used to augment cough strength, producing the greatest increase in peak cough flow compared with other techniques. These findings highlight the treatment options for the patient with neuromuscular disease in order to maintain respiratory muscle length, prevent infection and augment peak cough flow.