Maximal Inspiratory Mouth Pressure Research Articles

Obstructive and restrictive pulmonary dysfunctions in Parkinson's disease

Pulmonary dysfunction was investigated in fifty-eight Parkinson's patients. Clinical disability was assessed by the Unified Parkinson's Disease Rating Scale. Pulmonary dysfunction was studied by spirometry with flow-volume loops, body plethysmography with lung volumes computation and maximal inspiratory and expiratory static mouth pressures. Forced vital capacity (FVC), forced expiratory volume in 1 min (FEV1), FEV1 FVC% and arterial PO2 and PCO2 were significantly below normal values. Residual volume (RV) and total rows were above normal values. Thirty-six had upper airway obstruction as judged by inspiratory flow peaks (PIF) <31/s and FEV1 PEF% (expiratory flow peak) > 8.51/min and MEF50 MIF50 > 1. Eighteen patients had a central (FEV1 < 80% and FEV1 FVC% < 80% of normal values) or peripheral (maximal expiratory flow between 75% and 25% of FVC and maximal expiratory flow after expiration of 50% below 70% of normal values) obstructive pattern. Sixteen patients had a restrictive dysfunction as judged by a total lung capacity < 85% or FVC < 80% with FEV1 FVC% > 80%. Sixteen patients had air trapping (RV > 120% and RV TLC > 40%) and seven patients had lung insufflation (TLC > 120%). Rigidity, Rx signs of cervical arthrosis and limitations for passive movement of neck were higher in patients with central or peripheral airway obstruction. Bradykinesia and Rx signs of dorsal arthrosis was higher in patients with upper airway obstruction. Restrictive dysfunction was not related to tremor, rigidity or bradykinesia. The present data support the hypothesis that Parkinson patients present a high risk for pneumologic disturbances. These pulmonary dysfunctions are induced by the simultaneous action of a group of factors including the degree of bradykinesia or rigidity and the musculoskeletal limitations of vertebral column probably induced by chronic anomalous posture.

Nutritional status and mortality in chronic obstructive pulmonary disease.

The role of nutritional status in the prognosis of subjects with severe chronic obstructive pulmonary disease was studied in a cohort of Canadian men and women followed for 3 to 5 yr. A total of 348 subjects who were recruited for a study of negative pressure ventilation were evaluated for lung function and body weight, and a subset who entered hospital for the study (n=184) had baseline measures of diffusing capacity, maximal inspiratory and expiratory mouth pressure (PImax and PEmax), and blood gases. Predictors of survival were analyzed using Cox regression models. In the total cohort, low body mass index (BMI) and use of home oxygen were independently associated with reduced survival. In the hospitalized group, predictors of respiratory mortality were elevated PaCO2 and low BMI, PImax, and diffusing capacity. PaO2 (measured on oxygen therapy), FEV1, PEmax, age, smoking behavior, and gender were not associated with survival. The predictors of total mortality were similar, except that BMI was no longer significant. In conclusion, low body weight, a potentially modifiable factor, was associated with respiratory mortality, but whether it has a casual effect or is a marker of declining health can only be resolved through an intervention trial.

Obstructive and restrictive pulmonary dysfunction increases disability in Parkinson disease

Objective:: The purpose of this study was to determine in Parkinson disease the impact of pulmonary dysfunction on daily living activities (DLA). Patients:: Extrapyramidal motor impairment, pulmonary dysfunction, and DLA disabilities were studied in 58 Parkinson patients consecutively enrolled in a rehabilitation service at a universal hospital. Main Outcome Measures: Extrapyramidal motor impairments were assessed by the United Parkinson's Disease Rating Scale (IPDRS) and the DLA disabilities by the ipdrs, Hoehn-Yahr, and Schwab-England scales. The pulmonary dysfunctions were assessed by spirometry with flow-volume loops, body plethysmography with lung volumes computation, and maximal inspiratory and expiratory slatic mouth pressures. Results: Parkinson patients showed important modifications of pulmonary function with a decrease in forced vital capacity, forced expiratory volume in the first minute, and arterial P o 2, and an increase in residual volume and total airway resistance (RAW). In addition, they showed a high incidence of airway ventilatory obstructions and restrictive dysfunction. The impact of lung disease on daily living activities in Parkinson disease patients was higher in subjects with restrictive pulmonary dysfunctions (Schwab-England test and turning in bed and adjusting bedclothes, walking, falling, and freezing when walking items of UPDRS) and airway obstructions (handling utensils, dressing and hygiene items of UPDRS). Concusions: Airway obstructions or restrictive pulmonary dysfunctions present a high prevalence in Parkinson disease, contributing as a main factor for DLA dysfunctions. The evauation and rehabilitation of respiratory disturbances should be systematically included in the management of these patients.

Respiratory muscle strength after lung resection with special reference to age and procedures of thoracotomy.

Changes in respiratory muscle strength after lung resection were examined concerning age and procedures of thoracotomy. Maximum inspiratory (MIP) and expiratory (MEP) mouth pressure were measured before operation and 1, 2, 4, and 12 weeks after operation in 81 patients undergoing lung resection. In 48 patients undergoing pneumonectomy, lobectomy, or segmentectomy, patients older than 70 showed a significantly lower MIP and MEP before operation and throughout the postoperative period compared to younger ones (P < 0.01). Furthermore, the older patients showed a significantly lower percentage of postoperative MIP and MEP 4 weeks after operation than the younger ones (P < 0.01). In 31 patients undergoing lung wedge resection, patients undergoing limited thoracotomy (LT) and video-assisted thoracic surgery (VATS) showed significantly higher percentages of postoperative MIP and MEP than those undergoing posterolateral thoracotomy (PLT) 1 and 2 weeks after operation (P < 0.01 or 0.05). But there was no significant difference in the values between LT and VATS. We concluded that (1) elderly patients suffered respiratory muscle weakness before and after operation and their postoperative recovery of respiratory muscle strength was slower than in younger patients, and (2) VATS and LT resulted in more rapid recovery of respiratory muscle strength than PLT, but the difference between VATS and LT was not significant.

Impairment of lung volumes and respiratory muscle strength in adult patients with growth hormone deficiency

Little is known of the respiratory function in patients with growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient in childhood. Ten patients diagnosed as GH deficient in childhood and ten healthy subjects entered the study. For each subject the evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, recording of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Both maximal inspiratory and expiratory mouth pressures were decreased in GH deficiency. Vital capacity, N2 functional residual capacity and total lung capacity were significantly reduced when compared to healthy subjects. Conversely, the residual volume and diffusing lung capacity to CO did not show any significant change. No significant change of percentage forced expiratory volume in 1 s/forced vital capacity ratio was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. In conclusion, the results of this study show that adult patients affected with childhood onset GH deficiency suffer from impairment of ventilatory function and a decrease of respiratory muscle pressures, probably due to reduction of respiratory muscle strength.

Evaluation of the Short-Form 36-item Questionnaire to Measure Health-Related Quality of Life in Patients with COPD

Study objective To evaluate the short-form 36-item questionnaire (SF-36) as an instrument for measuring health-related quality of life (HRQL) in patients with symptomatic COPD. Design Observational data at a single point in time. Setting Outpatient pulmonary clinic. Patients Fifty male patients with COPD and no significant comorbidity. Measurements and results HRQL was assessed with the SF-36, which consists of 36 questions that cover nine health domains. Clinical ratings of dyspnea were measured by the multidimensional baseline dyspnea index (BDI). Pulmonary function tests included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ), and maximal inspiratory mouth pressure (PImax). The mean (± SD) age of the patients was 72 ± 8 years. The BDI focal score was 5.6 ± 2.3, FEV 1 was 1.32 ± 0.60 L (48 ± 22% pred), and PImax was 62 ± 23 cm H 2 O. The BDI focal score was significantly correlated with seven of nine components of the SF-36 (range of r, 0.42 to 0.91; p 1 percent of predicted and PImax were significantly correlated with five of nine health components (range of r, 0.30 to 0.65 and 0.31 to 0.61, respectively). Using linear regression model analysis with the different SF-36 components as the dependent variable and BDI, FVC, FEV 1 , and PImax as independent variables, the BDI score was the only significant predictor of social and physical functioning, role-physical, vitality, pain, health perceptions, and health transition (p Conclusions The SF-36 is a valid instrument to measure HRQL in patients with COPD. The severity of dyspnea but not respiratory function was a significant predictor of various components of HRQL.

In vivo assessment of diaphragm contraction by ultrasound in normal subjects.

Ultrasound allows observation of the thickness of the diaphragm in the zone of apposition in vivo during relaxation and maximum inspiratory efforts. Changes of diaphragm thickness were studied by B mode (two dimensional) ultrasound in 13 healthy men aged 29-54 years in the seated position. A high resolution 7.5 MHz ultrasound transducer was held perpendicular to the chest wall in the line of a right intercostal space between the anteroaxillary and mid-axillary lines to observe the diaphragm in the zone of apposition 0.5-2 cm below the costophrenic angle. The changes of thickness were observed while breath holding at total lung capacity (TLC), functional residual capacity (FRC), and residual volume (RV). At FRC the thickness while relaxing against a closed mouthpiece and during a maximum inspiratory mouth pressure (PImax) manoeuvre was recorded. The thickening ratio (TR) was calculated as TR = thickness during PImax manoeuvre/thickness while relaxing. Mean (SD) thickness was 4.5 (0.9) mm at TLC, 1.7 (0.2) mm at FRC, and 1.6 (0.2) mm at RV. During the PImax manoeuvre at FRC mean thickness increased from 1.7 (0.2) mm during relaxation to 4.4 (1.4) mm, while mean PImax and TR were -104 (33) cm H2O and 2.6 (0.7), respectively. There was a high degree of correlation between TR and the pressure achieved during the maximum inspiratory manoeuvre (r = -0.82). Ultrasound provides a non-invasive assessment of diaphragm thickness with change of lung volume and during the PImax manoeuvre which should prove useful in assessing diaphragm mass and contraction in respiratory and muscle disease.

Effects of posture on respiratory mechanics in obesity

Increased abdominal mass in obesity should enhance normal gravitational effects on supine respiratory mechanics. We have examined respiratory impedance (forced oscillation over 4-26 Hz applied at the mouth during tidal breathing), maximum inspiratory and expiratory mouth pressures (MIP and MEP), and maximum effort flow-volume curves seated and supine in seven obese subjects (O) (mean age 51 yr, body mass index 43.6 kg/m2) and seven control subjects (C) (mean age 50 yr, body mass index 21.8 kg/m2). Seated mean total lung capacity was smaller in O than in C (82 vs. 100% of predicted); ratio of functional residual capacity (FRC) to total lung capacity averaged 43% in O and 61% in C (P < 0.01). Total respiratory resistance (Rrs) at 6 Hz seated was higher in O (4.6 cmH2O.l-1.s) than in C (2.2 cmH2O.l-1.s; P < 0.001); total respiratory reactance (Xrs) at 6 Hz was lower in O than in C. In C, on changing to the supine posture, mean Rrs at 6 Hz rose to 2.9 cmH2O.l-1.s, FRC fell by 0.68 liter, and Xrs at 6 Hz showed a small fall. In O, despite no further fall in FRC, supine Rrs at 6 Hz increased to 7.3 cmH2O.l-1.s, and marked frequency dependency of Rrs and falls in Xrs developed. Seated, MIP and MEP in C and O were similar; supine there were small falls in MEP and maximum expiratory flow in O. The site and mechanism of the increase in supine Rrs and reduction in supine Xrs and the mechanism maintaining supine FRC in obesity all need further investigation.

Evaluation of the Short-Form 36-Item Questionnaire to Measure Health-Related Quality of Life in Patients With COPD

To evaluate the short-form 36-item questionnaire (SF-36) as an instrument for measuring health-related quality of life (HRQL) in patients with symptomatic COPD. Observational data at a single point in time. Outpatient pulmonary clinic. Fifty male patients with COPD and no significant comorbidity. HRQL was assessed with the SF-36, which consists of 36 questions that cover nine health domains. Clinical ratings of dyspnea were measured by the multidimensional baseline dyspnea index (BDI). Pulmonary function tests included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximal inspiratory mouth pressure (PImax). The mean (+/- SD) age of the patients was 72 +/- 8 years. The BDI focal score was 5.6 +/- 2.3, FEV1 was 1.32 +/- 0.60 L (48 +/- 22% pred), and PImax was 62 +/- 23 cm H2O. The BDI focal score was significantly correlated with seven of nine components of the SF-36 (range of r, 0.42 to 0.91; p < 0.05). The FEV1 percent of predicted and PImax were significantly correlated with five of nine health components (range of r, 0.30 to 0.65 and 0.31 to 0.61, respectively). Using linear regression model analysis with the different SF-36 components as the dependent variable and BDI, FVC, FEV1, and PImax as independent variables, the BDI score was the only significant predictor of social and physical functioning, role-physical, vitality, pain, health perceptions, and health transition (p < 0.05). The SF-36 is a valid instrument to measure HRQL in patients with COPD. The severity of dyspnea but not respiratory function was a significant predictor of various components of HRQL.

Nocturnal saturation and respiratory muscle function in patients with chronic obstructive pulmonary disease.

Nocturnal desaturations, mainly caused by hypoventilation, occur frequently in patients with chronic obstructive pulmonary disease (COPD). Daytime arterial oxygen and carbon dioxide tensions (PaO2 and PaCO2) appear to predict which patients will desaturate at night. It is unknown if respiratory muscle strength, which may be decreased in these patients, plays an additional part. Polysomnography, maximal respiratory pressures, lung function, and arterial blood gas tensions were measured in 34 patients with COPD (mean (SD) forced expiratory volume in one second (FEV1) 41.7 (19.9)% pred). Significant correlations were found between the mean nocturnal arterial oxygen saturation and maximal inspiratory mouth pressure (r = 0.65), maximal inspiratory transdiaphragmatic pressure (r = 0.53), FEV1 (r = 0.61), transfer coefficient (KCO) (r = 0.38), arterial oxygen saturation (SaO2) (r = 0.75), and PaCO2 (r = -0.44). Multiple regression analysis showed that 75% of the variance in nocturnal SaO2 (70%) and FEV1 (5%). Inspiratory muscle strength and nocturnal saturation data are correlated, but daytime SaO2 and FEV1 remain the most important predictors of nocturnal saturation.

Respiratory muscle strength in chronic heart failure.

Several studies have suggested that the respiratory muscles are weak in patients with heart failure, but the aetiology and clinical relevance of this weakness are unclear. In order to see if respiratory muscle weakness in this context is part of a more generalised myopathic process, respiratory and limb muscle strength were compared in patients with heart failure. The relation between respiratory muscle strength, breathlessness on exercise, and exercise capacity was also examined. Twenty patients (three women) with New York Heart Association (NYHA) class II-IV heart failure of mean age 63 years were studied. Respiratory muscle strength was assessed using maximum inspiratory and expiratory mouth pressures (MIP and MEP) and transdiaphragmatic pressure during sniffs (sniff PDI). These parameters were compared with cardiac output (indirect Fick) and with limb muscle strength as assessed by grip strength. The patients also performed two exercise tests during which they rated their breathlessness on a Borg scale. Mean (SD) cardiac index was 2.2 (0.4) l/min/m2. MIP and MEP were 66 (27) and 99 (29) cm H2O respectively. Sniff PDI was 103 (21) cm H2O and was positively correlated with grip strength and cardiac output (Spearman rank correlation coefficients 0.527 and 0.451, respectively). None of the indices of respiratory muscle strength were related to exercise time or breathlessness during exercise. The respiratory muscles are weak in patients with heart failure. This weakness reflects a more generalised myopathic process, possibly related to reduced cardiac output. However, respiratory muscle weakness does not appear to be an important factor in the aetiology of breathlessness on exercise.

Relationship Between Respiratory Muscle Strength and Lean Body Mass in Men With COPD

It has been suggested that low body weight may be associated with decreased respiratory muscle function in COPD, but the precise mechanism is not known. Since body compositional change inevitably accompanies body weight change, we decided to study the possible relationship between respiratory muscle strength and body composition in patients with COPD. We studied respiratory muscle strength, pulmonary function, and body composition in 24 Japanese male patients with COPD. Patients were divided into two groups according to their body weight (group A, body weight lower than 80% of ideal body weight vs group B, 80% or more) and a comparison was made together with age-matched controls (group C). Maximal inspiratory mouth pressure (PImax) and maximal expiratory mouth pressure (PEmax) were measured by a previously reported method. Body compositional analysis was performed using dual energy x-ray absorptiometry (DXA; Norland XR26). It showed significantly lower fat body mass (FAT), FAT/body weight%, and lean body mass (LEAN) in group A than those in group B. The PImax in group A was significantly lower than that in group B and C (44.2 +/- 13.8, 76.4 +/- 29.9, and 88.6 +/- 18.1 cm H2O, respectively). PEmax in group A was also significantly lower than that in group B and group C (61.9 +/- 20.1, 86.7 +/- 26.8, and 90.4 +/- 17.6 cm H2O, respectively). Both PImax and PEmax were significantly correlated with LEAN (r = 0.656, r = 0.591, p < 0.01, respectively) in patients with COPD. These results show that respiratory muscle strength is closely associated with body weight and lean body mass in patients with COPD. The present approach to compare respiratory muscle strength with lean body mass should be useful for studying the mechanism of respiratory muscle weakness in patients with COPD.

Inspiratory Muscle Training During Treatment With Corticosteroids in Humans

In a previous study performed by us, functional alterations in the inspiratory muscles were evaluated in patients receiving corticosteroids for diseases other than respiratory. We have shown that patients who received high-dose steroids for several weeks developed inspiratory muscle weakness that was reversible following withdrawal of the drug treatment. The present study was designed to evaluate the ability of specific inspiratory muscle training (SIMT) to prevent the effects of a therapeutic dosage of corticosteroids on inspiratory muscle function in patients receiving the drug for diseases other than pulmonary, with no underlying respiratory or muscular disease. Twelve patients, 5 men and 7 women, with ages ranging from 19 to 41 years, who received corticosteroids for diseases other than respiratory were recruited into two groups: 6 patients were assigned to the control group and got sham training and 6 patients received SIMT while receiving corticosteroids in a single-blind group-comparative trial. In both groups, there was no difference between the post-treatment and pretreatment values as regard to the FEV1/FVC relationship. However, in the control group but not in the training group, there was a small but significant decrease, from 99.2 +/- 3.0 to 94.3 +/- 2.8 (mean +/- SEM, p < 0.01) in FEV1 (percent of predicted normal values) and from 103.5 +/- 4.0 to 88.7 +/- 3.1 (p < 0.001) in the FVC, following treatment. All subjects had normal inspiratory muscle strength, as expressed by the maximal inspiratory mouth pressure (PImax) at residual volume, and inspiratory muscle endurance as expressed by the relationship between peak pressure and the PImax before treatment. Following administration of corticosteroids, there was a gradual decrease in both inspiratory muscle strength (from 117.5 +/- 9.4 to 80.5 +/- 3.3 cm H2O, p < 0.005) and endurance (from 82.7 +/- 2.6 to 40.2 +/- 1.7%, p < 0.001) in the control group. On the contrary, despite corticosteroid therapy, there were no significant changes in the inspiratory muscle function in the patients whose inspiratory muscles were specifically trained. We conclude that corticosteroids have a significant deteriorating effect on respiratory muscle function in humans. This weakness is preventable by using SIMT during corticosteroid treatment.

Inspiratory muscle weakness in chronic heart failure: role of nutrition and electrolyte status and systemic myopathy.

Inspiratory muscle weakness has been demonstrated in ambulatory, stable chronic heart failure (CHF) and may contribute to dyspnea during daily living. However, the mechanisms underlying this weakness are unknown. Malnutrition and electrolyte depletion are recognized complications of CHF that may impair skeletal muscle function, and limb muscle weakness and myopathic changes have also been demonstrated in CHF. We examined whether nutrition and electrolyte status contribute to the reduced skeletal muscle strength and whether inspiratory muscle weakness in CHF is part of general skeletal muscle weakness. We measured maximum inspiratory and expiratory mouth pressures as indices of respiratory muscle strength, maximum hand-grip strength as an index of limb muscle strength, anthropometric indices, serum albumin, and total lymphocyte count as indices of nutritional status, and serum electrolytes in 15 stable patients with chronic cardiac pump failure who had no evidence of primary lung disease, and in 15 age-and-sex-matched healthy controls. As compared with the matched controls, the CHF patients had reduced inspiratory muscle strength (p < 0.0025), but their expiratory and limb muscle strength were not significantly reduced. CHF patients were not malnourished; they were heavier than matched controls because of increased body fat (p < 0.05). Serum sodium was significantly lower in the CHF patients than in the controls (p < 0.01), but was within the normal range in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Body Position, Hyperinflation, and Blood Gas Tensions on Maximal Respiratory Pressures in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND--Inspiratory muscle strength in patients with chronic obstructive pulmonary disease (COPD) can be affected by mechanical factors which influence the length of the diaphragm, and by non-mechanical factors. The aim of the present study was to evaluate firstly the effects of body position on respiratory pressures and, secondly, to determine the relative contribution of age, body mass index (BMI), lung volumes, and arterial blood gas tensions to respiratory muscle strength. METHODS--Thirty male patients with stable COPD (mean FEV1 40.4% predicted) participated in the study. Maximal inspiratory and expiratory mouth pressures (PImax, PEmax) and maximal inspiratory transdiaphragmatic pressures (PDI) in the sitting and supine position, lung function, and arterial blood gas tensions were measured. RESULTS--Mean (SD) PImax in the sitting position was higher than in the supine position (7.1(2.3)kPa v 6.4(2.2)kPa respectively). In contrast, PDI in the sitting position was lower than in the supine position (10.0(3.5)kPa v 10.8(3.7)kPa respectively). PEmax was higher in the sitting position (9.3(3.0)kPa) than in the supine position (8.7(2.8)kPa). Significant correlations were found between inspiratory muscle strength on the one hand, and lung function parameters, BMI, and arterial blood gas tensions on the other. CONCLUSIONS--Inspiratory muscle strength in patients with COPD is influenced by mechanical factors (body position, lung volumes) and non-mechanical factors (BMI, FEV1, and blood gases). PImax and PEmax are lower in the supine position while, in contrast to healthy subjects, PDI is higher in the supine position than in the sitting position.

Benefit of Selective Respiratory Muscle Training on Exercise Capacity in Patients With Chronic Congestive Heart Failure

Diminished respiratory muscle strength and endurance have been demonstrated in patients with heart failure. This may contribute to exertional dyspnea and reduced exercise capacity in these patients. The purpose of this study was to investigate whether selective respiratory muscle training could alleviate dyspnea and improve exercise performance in patients with chronic congestive heart failure. Fourteen patients with chronic heart failure (left ventricular ejection fraction, 22 +/- 9%) were enrolled in a supervised respiratory muscle training program. This consisted of three weekly sessions of isocapnic hyperpnea at maximal sustainable ventilatory capacity, resistive breathing, and strength training. Maximum sustainable ventilatory capacity, maximum voluntary ventilation, maximal inspiratory and expiratory pressures, peak VO2, and the 6-minute walk test were measured before (pre) and after (post) 3 months of training. Eight patients completed the training program. Respiratory muscle endurance was improved with training, as evidenced by increases in maximal sustainable ventilatory capacity (pre, 48.6 +/- 10.7 versus post, 76.9 +/- 14.5 L/min; P < .05) and in maximal voluntary ventilation (pre, 100 +/- 36 versus post, 115 +/- 39 L/min; P < .05). Respiratory muscle strength was also increased with training as maximal inspiratory (pre, 64 +/- 31 versus post, 78 +/- 33 cm, H2O; P < .01) and expiratory (pre, 94 +/- 30 versus post, 133 +/- 53 cm H2O; P < .001) pressures rose. Submaximal and maximal exercise capacity were significantly improved with selective respiratory muscle training as the 6-minute walk (pre, 1101 +/- 351 versus post, 1421 +/- 328 ft; P < .001) and peak exercise VO2 (pre, 11.4 +/- 3.3 versus post, 13.3 +/- 2.7 mL.kg-1.min-1; P < .05) both significantly increased. Dyspnea during activities of daily living was subjectively improved in the majority of trained patients. Dyspnea quantified by the Borg scale was significantly reduced during progressive isocapnic hypernea but not during bicycle exercise. No statistically significant improvement in maximal sustainable ventilatory capacity, maximum voluntary ventilation, maximal inspiratory or expiratory mouth pressures, 6-minute walk, or peak VO2 was observed in the 6 patients who did not complete the training program. Selective respiratory muscle training improves respiratory muscle endurance and strength, with an enhancement of submaximal and maximal exercise capacity in patients with heart failure. Dyspnea during activities of daily living was subjectively improved in the majority of trained patients.

Nutritional depletion in relation to respiratory and peripheral skeletal muscle function in out-patients with COPD

Although increasing attention has been paid to nutritional aspects in chronic obstructive pulmonary disease (COPD), limited information is available regarding the prevalence and consequences of nutritional depletion in a random out-patient COPD population. We studied body composition in relation to respiratory and peripheral skeletal muscle function in 72 COPD patients (mean (SD) forced expiratory volume in one second (FEV1) 53 (15) % predicted), who came to the lung function laboratory for routine lung function measurements. Patients were characterized by the degree of body weight loss and fat-free mass depletion. According to this definition, 14% of the group suffered from both loss of body weight and depletion of fat-free mass, whereas 7% had one of these conditions. We found that tissue depletion was concomitant with lower values for respiratory and peripheral skeletal muscle strength (46.0 (27.2) vs 77.1 (29.8) kg), and a significantly lower transfer coefficient for carbon monoxide (KCO 64.9 (16.2) vs 81.9 (24.5) % pred). Stratification by KCO (< 60% vs > 80%) also revealed significantly lower values for fat-free mass and higher values for intrathoracic gas volumes, total lung capacity (TLC) and residual volume (RV) in the group with a KCO < 60% pred. Analysis of covariance, taking fat-free mass as covariate, indicated an independent contribution of KCO on maximal inspiratory mouth pressure (PImax) but not on peripheral skeletal muscle strength. It is concluded that a substantial number of COPD out-patients suffer from nutritional depletion, preferentially affecting peripheral skeletal muscle function.

The effect of a comprehensive, intensive inpatient treatment program on lung function and exercise capacity in patients with cystic fibrosis.

The purpose of this investigation was to measure the effects of a 10- to 14-day comprehensive, intensive hospital treatment program on peak exercise capacity, endurance capacity, respiratory function, weight change, and maximum inspiratory and expiratory mouth pressures in patients with cystic fibrosis with a pulmonary exacerbation. Fourteen young adults with cystic fibrosis admitted to a hospital for an exacerbation of their pulmonary disease were studied. Subjects performed pulmonary function tests, inspiratory and expiratory mouth pressure tests, and stationary bicycle exercise tests at admission and discharge. Comprehensive therapy provided during the hospital admission consisted of intravenous antibiotics, physical therapy, high-calorie diet, and daily medical review. The patients showed improvements in forced expiratory volume in 1 second (46%-55% of predicted values) and forced vital capacity (62%-68% of predicted values). Maximum inspiratory and expiratory mouth pressures also improved (118%-131% and 78%-92% of predicted values, respectively). There was a mean weight gain of 2 kg. Maximum work capacity on a bicycle ergometer improved from a mean of 45% to 52% of predicted values. The most impressive result was the marked increase in exercise endurance time from a mean of 9.5 minutes on admission to 16.6 minutes at discharge. This study indicates that young adults with cystic fibrosis and an exacerbation of their pulmonary disease obtain measurable benefits from a comprehensive, intensive treatment program, particularly improvement in their capacity for endurance exercise.

Preoperative Respiratory Muscle Training: Assessment in Thoracic Surgery Patients With Special Reference to Postoperative Pulmonary Complications

To assess the usefulness of preoperative respiratory muscle training to increase muscle strength and its effects on postoperative pulmonary complications. We measured maximum inspiratory (MIP) and maximum expiratory (MEP) mouth pressure before and after training in 50 patients undergoing thoracic surgery. For control purposes, MIP and MEP were measured in 50 age- and sex-matched healthy subjects at two different times without training. Preoperative respiratory muscle training increased both MIP and MEP significantly (p < 0.01), while the control subjects showed no increase in these parameters. Eight patients who had postoperative pulmonary complications had significantly lower values (p < 0.01) and did not show significant increases in either MIP or MEP even after the training, unlike the other patients, who were without postoperative pulmonary complications. On the other hand, there were also another six patients who had equally low MIP and MEPs before training, but who raised their values with training and avoided the postoperative pulmonary complications. Preoperative respiratory muscle training may prevent postoperative pulmonary complications by increasing both inspiratory and expiratory muscle strength in patients undergoing thoracic surgery. Patients with respiratory muscle weakness have a higher risk of postoperative pulmonary complications.

Effects of body position, hyperinflation, and blood gas tensions on maximal respiratory pressures in patients with chronic obstructive pulmonary disease.

Inspiratory muscle strength in patients with chronic obstructive pulmonary disease (COPD) can be affected by mechanical factors which influence the length of the diaphragm, and by non-mechanical factors. The aim of the present study was to evaluate firstly the effects of body position on respiratory pressures and, secondly, to determine the relative contribution of age, body mass index (BMI), lung volumes, and arterial blood gas tensions to respiratory muscle strength. Thirty male patients with stable COPD (mean FEV1 40.4% predicted) participated in the study. Maximal inspiratory and expiratory mouth pressures (PImax, PEmax) and maximal inspiratory transdiaphragmatic pressures (PDI) in the sitting and supine position, lung function, and arterial blood gas tensions were measured. Mean (SD) PImax in the sitting position was higher than in the supine position (7.1(2.3)kPa v 6.4(2.2)kPa respectively). In contrast, PDI in the sitting position was lower than in the supine position (10.0(3.5)kPa v 10.8(3.7)kPa respectively). PEmax was higher in the sitting position (9.3(3.0)kPa) than in the supine position (8.7(2.8)kPa). Significant correlations were found between inspiratory muscle strength on the one hand, and lung function parameters, BMI, and arterial blood gas tensions on the other. Inspiratory muscle strength in patients with COPD is influenced by mechanical factors (body position, lung volumes) and non-mechanical factors (BMI, FEV1, and blood gases). PImax and PEmax are lower in the supine position while, in contrast to healthy subjects, PDI is higher in the supine position than in the sitting position.