Margalit Weiner

Influence of excessive weight loss after gastroplasty for morbid obesity on respiratory muscle performance.

BACKGROUND: Morbidly obese subjects are known to have impaired respiratory function and inefficient respiratory muscles. A study was undertaken to investigate the influence of excessive weight loss on pulmonary and respiratory muscle function in morbidly obese individuals who underwent gastroplasty to induce weight loss. METHODS: Twenty one obese individuals with mean (SE) body mass index (BMI) 41.5 (4.5) kg/m2 without overt obstructive airways disease (FEV1/FVC ratio > 80%) were studied before and six months after vertical banded gastroplasty. Only patients who had lost at least 20% of baseline BMI were included in the study. Standard pulmonary function tests and respiratory muscle strength and endurance were measured. RESULTS: Before operation the predominant abnormalities in respiratory function were significant reductions in lung volumes and respiratory muscle endurance and, to a lesser degree, reductions in respiratory muscle strength. All parameters increased towards normal values after weight loss with significant increases in functional residual capacity (FRC) from 84.0 (2.2) to 91.3 (2.5)% of predicted normal values (mean difference 7.3, 95% confidence interval of difference (CI) 4.2 to 10.5), total lung capacity (TLC) from 85.6 (3.0) to 93.5 (3.7)% of predicted normal values (mean difference 7.9, 95% CI 4.5 to 11.5), residual volume (RV) from 86.7 (3.1) to 96.4 (3.0) of predicted normal values (mean difference 9.7, 95% CI 5.2 to 14.1), expiratory reserve volume (ERV) from 76.6 (3.0) to 89.0 (3.4)% of predicted normal values (mean difference 12.4, 95%, CI 6.3 to 18.9), respiratory muscle strength: PImax from 92 (4.4) to 113 (4.6) cm H2O (mean difference 21, 95% CI 12.2 to 31.6), PEmax from 144 (5.6) to 166 (4.3) cm H2O (mean difference 22, 95% CI 12.9 to 32.0), and endurance: PmPeak/PImax from 56 (1.4) to 69 (2.0)% (mean difference 13, 95% CI 9.7 to 16.9). The strongest correlation was between weight loss and the improvement in respiratory muscle endurance. CONCLUSIONS: Lung volumes and respiratory muscle performance are decreased in obese individuals. Weight loss following gastroplasty is associated with improvement in lung volumes and respiratory muscle function.

The effect of incentive spirometry and inspiratory muscle training on pulmonary function after lung resection

BACKGROUND A predicted postoperative forced expiratory volume in 1 second (FEV1) of less than 800 ml or 40% of predicted is a common criterion for exclusion of patients from lung resection for cancer. Usually, the predicted postoperative lung function is calculated according to a formula based on the number of lung segments that will be resected. Incentive spirometry and specific inspiratory muscle training are two maneuvers that have been used to enhance lung expansion and inspiratory muscle strength in patients with chronic obstructive pulmonary disease and after lung operation. METHODS Thirty-two patients with chronic obstructive pulmonary disease who were candidates for lung resection were randomized into two groups: 17 patients received specific inspiratory muscle training and incentive spirometry, 1 hour per day, six times a week, for 2 weeks before and 3 months after lung resection (group A) and 15 patients were assigned to the control group and received no training (group B). RESULTS Inspiratory muscle strength increased significantly in the training group, both before and 3 months after the operation. In group B, the predicted postoperative FEV1 value consistently underestimated the actual postoperative FEV1 by approximately 70 ml in the lobectomy subgroup and by 110 ml in the pneumonectomy subgroup. In group A, the actual postoperative FEV1 was higher than the predicted postoperative FEV1 by 570 ml in the lobectomy subgroup and by 680 ml in the pneumonectomy subgroup of patients. CONCLUSIONS In patients undergoing lung resection the simple calculation of predicted postoperative FEV1 underestimates the actual postoperative FEV1 by a small fraction. Lung functions can be increased significantly when incentive spirometry and specific inspiratory muscle training are used before and after operation.

Prophylactic Inspiratory Muscle Training in Patients Undergoing Coronary Artery Bypass Graft

Pulmonary complications after cardiac surgery are a leading cause of postoperative morbidity and mortality. Respiratory muscle weakness may contribute to the postoperative pulmonary abnormalities. We hypothesized that: (1) there is a decrease in inspiratory muscle strength (PImax at residual volume) and endurance (Pmpeak/PImax) following coronary artery bypass graft (CABG); (2) this weakness is associated with reduced pulmonary function tests (PFTs), impaired gas exchange, and a higher rate of pulmonary complications; and (3) prophylactic inspiratory muscle training (IMT) can prevent those changes. Eighty-four candidates for CABG, with ages ranging from 33 to 82 years, were evaluated prior to operation and randomized into two groups: 42 patients underwent IMT using a threshold trainer for 30 min/day for 2 weeks, 1 month before operation (group A); 42 patients served as a control group and underwent sham training (group B). There was a significant decrease in respiratory muscle function, PFTs, and gas exchange in the control group following CABG, whereas these parameters remained similar to those before entering the study in the training group. The differences between the groups were statistically significant. In addition, 11 (26%) patients in the control group but only 2 (5%) in the training group needed postsurgical mechanical ventilation longer than 24 hours. CABGs have a significant deteriorating effect on inspiratory muscle function, PFTs, and arterial blood gases. The decrease in these parameters can be prevented by prophylactic inspiratory muscle training, which may also prevent postsurgical pulmonary complications.

Long term clinical comparison of single versus twice daily administration of inhaled budesonide in moderate asthma.

BACKGROUND--Inhaled steroids are widely used in the treatment of mild to moderate asthma. However, long term compliance with inhaled steroids is poor and administration of a single daily dose may improve compliance. METHODS--A double blind, randomised study was performed to determine whether inhaled steroids given once daily at bedtime are as efficacious as a twice daily regimen in the long term maintenance of moderate asthmatic patients. Forty adults of mean age 37 years with moderate asthma (mean (SE) forced expiratory volume in one second (FEV1) 73.6 (1.4)% predicted, mean morning peak expiratory flow (PEF) 328 l/min) were randomised to receive either a twice daily dose (400 micrograms morning and bedtime) of inhaled budesonide (group A) or a once daily dose of 800 micrograms (group B) and were followed for a period of 12 months. Asthma symptom scores (assessed according to a modified Borg scale), inhaled beta 2 agonist consumption, and peak expiratory flow rates were recorded daily. Spirometry and airways responsiveness to methacholine (PC20) were measured at the end of each period of three months of treatment. RESULTS--There was no difference between the two groups at baseline and during the follow up period in the PC20 for methacholine. However, a difference was seen between the two groups in the mean daily number of beta 2 agonist inhalations (1.4 (0.1) puffs/patient/day in group A v 2.3 (0.1) in group B), the PEF variability (episodes of decrease in PEF of > 20%) (0.22 (0.01) episodes/patient/day in group A v 0.40 (0.02) in group B), and for asthma symptom scores (0.30 (0.04) in group A v 0.42 (0.06) in group B) for the 12 month period of the study. CONCLUSIONS--Although both regimens provide good clinical control, twice daily doses of 400 micrograms inhaled budesonide are more effective than a single dose of 800 micrograms at bedtime in the long term control of stable moderate asthma.

Respiratory muscle training in patients with moderate to severe myasthenia gravis.

BACKGROUND Myasthenia gravis (MG) is a specific autoimmune disease characterized by weakness and fatigue. MG may affect also the respiratory muscles causing symptoms that may vary from dyspnea on severe exertion to dyspnea at rest. This study was undertaken in order to determine the effects of respiratory muscle training on respiratory muscle performance, spirometry data and the grade of dyspnea in patients with moderate to severe generalized MG. METHODS Eighteen patients with MG were studied and divided into 2 groups: Group A included 10 patients (3 males and 7 females aged 29-68) with moderate MG, and Group B that included 8 patients (5 males and 3 females aged 21-74) with severe MG. Patients in Group A received both inspiratory and expiratory muscle training for 1/2 h/day, 6 times a week, for 3 months, while patients in Group B followed the same protocol but had inspiratory muscle training only. RESULTS Mean PImax increased significantly from 56.6 +/- 3.9 to 87.0 +/- 5.8 cm H2O (p < 0.001) in Group A, and from 28.9 +/- 5.9 to 45.5 +/- 6.7 cm H2O (p < 0.005) in Group B. The mean PEmax also increased significantly in patients in Group A, but remained unchanged in the patients in Group B. The respiratory muscle endurance also increased significantly, from 47.9 +/- 4.0 to 72.0 +/- 4.2%, p < 0.001, in patients of Group A, and from 26.0 +/- 2.9 to 43.4 +/- 3.8, p < 0.001, in patients in Group B. The improved respiratory muscle performance was associated with a significant increase in the FEV1 values, and in the FVC values, in patients of both groups. Mean dyspnea index score also increased significantly from 2.6 +/- 0.8 to 3.6 +/- 0.4 (p < 0.005) in Group A, and from 0.7 +/- 0.2 to 2.0 +/- 0.2 (p < 0.001) in Group B. CONCLUSIONS Specific inspiratory threshold loading training alone, or combined with specific expiratory training, markedly improved respiratory muscle strength and endurance in patients with MG. This improvement in respiratory muscle performance was associated with improved lung function and decreased dyspnea. Respiratory muscle training may prove useful as a complementary therapy with the aim of reducing dyspnea symptoms, delay the breathing crisis and the need for mechanical ventilation in patients with MG.

The response to inhaled and oral steroids in patients with stable chronic obstructive pulmonary disease

Background. A significant minority of patients with COPD have favourable response to corticosteroid treatment. In addition, the benefit of corticosteroid treatment may be outweighed by the side‐effects. Long‐term administration of inhaled steroids is a safe means of treatment. However, only a few studies have addressed the role of inhaled steroids in patients with COPD, with conflicting results.

Inspiratory Muscle Training May Increase Peak Inspiratory Flow in Chronic Obstructive Pulmonary Disease

Background: When choosing a specific inhalation device for a chronic obstructive pulmonary disease (COPD) patient, the internal airflow resistance and the ability of the patient to overcome it and to create an optimal inspiratory flow are essential. Objectives: The purpose of the present study was to investigate: (1) the peak inspiratory flow (PIF) that a patient with COPD can generate while breathing through two dry powder inhalers and (2) whether in patients with low PIF specific inspiratory muscle training (SIMT) will increase the PIF and exceed the minimal PIF that is considered necessary to guarantee optimal lung deposition of the drug. Methods: Inspiratory muscle strength and PIFs were measured in 60 patients with COPD. Then 28 patients with severe COPD and low PIF were randomized to receive SIMT or to a control group. Results: With the Turbuhaler, 12 patients (20%) could not generate the optimal flow of 60 l/min. PIF correlated very well with maximal inspiratory mouth pressure (PImax) for the Diskus and the Turbuhaler, as well as for both males and females (p < 0.001). Following the training period, there was a statistically significant increase in the PImax in the training group. This increase was associated with a significant increase in the PIF. All patients overcame the minimal threshold PIF following the training. Conclusions: Some patients with severe COPD are not able to generate adequate flow to secure optimal lung deposition of the inhalation with the Turbuhaler. SIMT improves inspiratory muscle strength as well as PIF. Following 8 weeks of training, the optimal PIF enabling adequate lung deposition of the drug was attained in all the trained patients.