Airway obstruction and airway wall instability in cystic fibrosis: the isolated and combined effect of theophylline and sympathomimetics

Beneficial short-term effect of autogenic drainage on peripheral resistance in childhood cystic fibrosis disease

Background

Airway clearance techniques are supposed to be a necessary adjunct for the enhancement of impaired peripheral clearance in cystic fibrosis (CF). The objective was to assess the effect of one physiotherapy session (autogenic drainage: AD) on mucus clearance (sputum wet weight) and impulse oscillometry system (IOS) indices, including those obtained from extended Resistance-Inertance-Compliance (eRIC) modelling, considering the degree of bronchial congestion.

Methods

Thirty children with CF (median age: 12.7 years) in a stable condition prospectively underwent IOS measurements at baseline and after AD. They were divided in two groups: with (visual analog scale of bronchial congestion by the physiotherapist ≥ 5/10) and without (scale < 5/10) bronchial congestion. Paired-comparison of the effects of AD on airway resistance measurements was done with Wilcoxon test.

Results

The congestion scale correlated with the wet weight of sputum production during the session (Pearson test: p < 0.0001, R = 0.66). Ten children had bronchial congestion and 20 were without congestion. In the whole group, R5–20 Hz significantly decreased after AD (P = 0.049), which was related to a decrease in the children with congestion (P = 0.025), whereas it was not significantly modified in the children without congestion (P = 0.327). The eRIC model allowed the calculation of the peripheral resistance of the respiratory system, which also decreased in the children with congestion (P = 0.037), however, not modified in the children without congestion (P = 0.390).

Conclusion

One session of autogenic drainage has the ability to decrease peripheral resistance obtained from IOS measurements, more specifically in children with CF with moderate to severe bronchial congestion.

Trial registration

ClinicalTrials.gov Identifier: NCT04094441.

Effect of Salbutamol on Lung Ventilation in Children with Cystic Fibrosis: Comprehensive Assessment Using Spirometry, Multiple-Breath Washout, and Functional Lung Magnetic Resonance Imaging

BACKGROUND

Inhalation therapy is one of the cornerstones of the daily treatment regimen in patients with cystic fibrosis (CF). Recommendations regarding the addition of bronchodilators, especially salbutamol are conflicting due to the lack of evidence. New diagnostic measures such as multiple-breath washout (<underline>MBW)</underline> and functional magnetic resonance imaging (MRI) have the potential to reveal new insights into bronchodilator effects in patients with CF.

OBJECTIVE

The objective of the study was to comprehensively assess the functional response to nebulized inhalation with salbutamol in children with CF.

METHODS

Thirty children aged 6-18 years with stable CF performed pulmonary function tests, MBW, and matrix pencil-MRI before and after standardized nebulized inhalation of salbutamol.

RESULTS

Lung clearance index decreased (improved) by -0.24 turnover (95% confidence interval [CI]: -0.53 to 0.06; p = 0.111). Percentage of the lung volume with impaired fractional ventilation and relative perfusion decreased (improved) by -0.79% (CI: -1.99 to 0.42; p = 0.194) and -1.31% (CI: -2.28 to -0.35; p = 0.009), respectively. Forced expiratory volume (FEV1) increased (improved) by 0.41 z-score (CI: 0.24-0.58; p < 0.0001). We could not identify specific clinical factors associated with a more pronounced effect of salbutamol.

CONCLUSIONS

There is a positive short-term effect of bronchodilator inhalation on FEV1 in patients with CF, which is independent of ventilation inhomogeneity. Heterogeneous response between patients suggests that for prediction of a therapeutic effect this should be tested by spirometry in every patient individually.

Reversible airway obstruction in cystic fibrosis: Common, but not associated with characteristics of asthma

BACKGROUND

As asthma-like symptoms are common in CF, we evaluated reversible airway obstruction and associated characteristics.

METHODS

Retrospective analysis of charts including spirometry and bronchodilator response.

RESULTS

Of 190 CF patients (103 at Schneider's, 87 at Hadassah), aged 14.4 (4-76) years, median (range), 39% had reversible obstruction (ΔFEV1% predicted ≥12%), associated with younger age (p=0.01) and severe genotype (p=0.02). There was no association with family history of asthma, serum IgE, blood eosinophils, pancreatic status, FEV1<40% predicted, Aspergillus or pseudomonas infection. Of patients with reversible obstruction, 74% were on bronchodilator and 68% on inhaled corticosteroid therapy but 54% and 57% respectively receiving these therapies did not have reversible obstruction.

CONCLUSIONS

Reversible airway obstruction is common in CF, more frequent in younger patients and with severe genotype, with no correlation to markers of atopy or CF clinical severity. Bronchodilator and inhaled corticosteroid therapies are commonly prescribed even without reversible obstruction.

Domiciliary Positive Expiratory Pressure Improves Pulmonary Function and Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND/PURPOSE

This study assessed how positive expiratory pressure (PEP) affected pulmonary function, functional capacity, and subjective cough difficulty in individuals with chronic obstructive pulmonary diseases (COPD).

METHODS

This was a prospective, randomized, controlled study. Subjects were recruited from an outpatient department at a university hospital. Thirty-two patients with COPD were allocated to either PEP + FET (forced expiratory technique) group (n = 16) or FET only group (n = 16). Subjects in PEP + FET and FET groups were in a clinically stable condition before and during the study. Subjects in the PEP + FET group received PEP breathing using a mouth adjunct to FET, and the FET group was administered FET for 4 weeks only. Patients received weekly follow-up during the study period. Pulmonary function, 6-minute walk tests, and subjective cough difficulty scores were measured before and after the 4-week interventions.

RESULTS

Subjects in the PEP + FET group had a significantly increased diffusing capacity (DLCO) compared to preintervention (p < 0.05) and after intervention in the FET group (p < 0.05). DLCO significantly increased in the PEP + FET group from 18.0 +/- 7.3 to 20.1 +/- 7.2 mL/min/mmHg. The 6-minute walking distance (6MWD) also increased significantly from 516.8 +/- 94.1 to 570.6 +/- 60.4 m in the PEP + FET group (p < 0.001) after intervention, compared to that for the FET group (p < 0.05). Additionally, the PEP + FET group had significantly lower cough difficulty scores compared to those at baseline and in the FET group.

CONCLUSION

Four-week PEP therapy as an adjunct to FET further enhanced DLCO and 6MWD, and reduced cough difficulty compared to FET only in COPD patients with mucus hypersecretion.

Treatment of severe small airways disease in children with cystic fibrosis: alternatives to corticosteroids

A group of patients with cystic fibrosis (CF) have severe small airways disease characterized by wheeze, chest tightness and limited sputum production, often with deteriorating lung function. Suggested mechanisms include mucosal edema secondary to infection and inflammation, smooth muscle contraction caused by inflammatory mediators, and collapse of bronchiectatic airways. While treatment with long-term oral corticosteroids may result in symptomatic improvement, adverse effects often make them intolerable. Inhaled corticosteroids are used in many centers despite the lack of conclusive evidence of their efficacy. Therapeutic alternatives to corticosteroids are aimed at reversing bronchoconstriction and reducing inflammation. Many patients with CF are treated with short- and long-term inhaled bronchodilators, but data to support their use are inconclusive. Other attempted routes of administration for short-acting bronchodilators include the subcutaneous and intravenous routes, but clinical data are again lacking. Sodium cromoglycate (cromolyn sodium) has been studied, with little evidence of benefit. Theophyllines have also been studied, both intravenously and orally, with some effect, but are not often used in clinical practice. Nonsteroidal anti-inflammatory therapies include ibuprofen, macrolide antibiotics, intravenous immunoglobulin, cyclosporine, and leukotriene antagonists. Ibuprofen has been shown to be useful in patients with mild CF disease, but concerns about potential adverse effects have limited its use. The results of various macrolide studies are awaited, but to date there are no long-term studies published. While there is great interest in the potential of intravenous immunoglobulin, cyclosporine and leukotriene antagonists, the evidence for their effectiveness comes from anecdotal reports, thus there is currently insufficient data to support their use. Since this is a small group of patients, it is unlikely that sufficient numbers will ever be recruited for these studies; thus it is probable that drugs will be tried on an individual patient basis. The order in which they are attempted is unclear, but it would be sensible to try the least invasive medication with the least adverse effects first, moving on to more potent, but more toxic drugs if that treatment fails.

"CF asthma": what is it and what do we do about it?

The diagnosis of "CF asthma" is problematic and it is difficult to determine which patients have a combination of CF and asthma and which have asthma like symptoms caused by inflammation of the CF lung. This may not matter, however; the relevance lies in the possible approaches to treatment.

Effects of salmeterol on arterial oxyhemoglobin saturations in patients with cystic fibrosis

Sleep-related oxygen desaturation has been described in patients with cystic fibrosis (CF). Thus we studied the effects of inhaled Salmeterol xinafoate, a long-acting beta-2 agonist, on transcutaneous oxyhemoglobin saturation in sleeping, stable CF patients. Patients with stable CF (n = 23) were divided into responders and nonresponders to beta-2 agonists, based on an albuterol challenge during daytime testing, and then they received salmeterol before sleep, in a double-blind crossover design. Overnight oxyhemoglobin saturation measurements and spirometry on awakening were performed. Salmeterol administration before sleep resulted in statistically significant increases in mean arterial oxyhemoglobin saturation and in FEV(1) and FEF(25-75) on awakening compared to placebo values, but only in patients responding to daytime albuterol inhalation by showing improvement in lung function. We conclude that salmeterol inhalation at bedtime could prevent or reduce nocturnal hypoxemia in daytime albuterol-responsive CF patients, thus improving the long-term clinical outcome of CF lung disease.

Atelectasis: mechanisms, diagnosis and management

The term atelectasis describes a state of collapsed and non-aerated region of the lung parenchyma, which is otherwise normal. This pathological condition is usually associated with several pulmonary and chest disorders and represents a manifestation of the underlying disease, not a disease per se. Atelectasis may occur in three ways: (i) airway obstruction; (ii) compression of parenchyma by extrathoracic, intrathoracic, chest wall processes; and (iii) increased surface tension in alveoli and bronchioli. Chest radiographs using both the anterior-posterior and lateral projections are mandatory to document the presence of atelectasis. Differentiation from lobar consolidation may be a clinical dilemma. The treatment of atelectasis varies depending on duration and severity of the causal disease from chest physiotherapy to postural drainage, bronchodilator and anti-inflammatory therapy. Persistent mucous plugs should be removed by bronchoscopy.

Effects of standard and high doses of salmeterol on lung function of hospitalized patients with cystic fibrosis

In a recent investigation we found that hospitalized patients with cystic fibrosis who received 0.5 cc of 0.5% albuterol nebulizer solution TID significantly increased their pulmonary function across the day, but fell back to baseline overnight. To determine whether this fall could be prevented by the long-acting beta-2 agonist salmeterol at both standard (2 puffs: 42 mcg BID) and high (4 puffs, 84 mcg BID) doses, we evaluated the effects of salmeterol vs. albuterol (2 puffs, 180 mcg QID, and 4 puffs, 360 mcg BID) in a placebo-controlled three-way random crossover, double-blind trial. Eighteen patients in the low-dose group and 10 of the same 18 patients in the high-dose group completed the 3 consecutive days of testing and received either salmeterol, albuterol, or placebo with each of four chest physiotherapy sessions given at 7 AM, 11 AM, 3 PM, and 7 PM. At standard doses (2 puffs), the mean percent changes in FEV1 pre- to post-7 AM therapy for salmeterol (5.5%) and albuterol (9.9%) were significantly greater than with placebo (-1.2%) (P < 0.05 and 0.01, respectively). The mean percent changes in FEV1 from morning baseline with salmeterol were also significantly greater than placebo before 3 PM (12.1% vs. 5.4%, P < 0.01), and neither albuterol nor salmeterol were significantly greater than placebo after 3 PM. At standard doses there was a significant carryover effect with salmeterol to the next morning for the FEV1 (7.3%) when compared to placebo (1.5%) and albuterol (-0.7%) (P < 0.05 and 0.05, respectively). At high doses (4 puffs), the mean percent change in FEV1 with pre- to post-7 AM therapy increased to 22.7% and remained significantly greater than with placebo until pretherapy at 7 PM. The carryover effect the next morning was 14.7%. Salmeterol at 4 puffs compared favorably to albuterol nebulizer therapy given TID in both the incidence of responders for the FEV1 (70% vs. 71%) and the mean changes after therapy at 7 AM (22.7% vs. 14.9%), and provided greater carryover effects to the next morning (14.7% vs. -0.7%), thus preventing the fall in pulmonary function back to baseline overnight. We recommend the use of high-dose salmeterol in hospitalized patients with FVC values of 40% of predicted or greater, starting with 2 and increasing to 4 puffs BID as tolerated.

Primary ciliary dyskinesia: evolution of pulmonary function

Pulmonary function tests were obtained in 11 patients with primary ciliary dyskinesia. Their mean age was 15 years (range 6-32). Their pulmonary function was obstructive, with a vital capacity (mean+/-SD) of 75%+/-20% predicted, a forced expiratory volume in 1s (FEV1) of 63%+/-20% predicted and a raised residual volume of 169%+/-50% predicted. After inhalation of 200 microg of salbutamol the mean change in FEV1 was + 13.2%+/-9.6% of the baseline value. In the 10 oldest patients, lung function had been measured at regular intervals during 3 20 years. Interestingly, during childhood and adolescence the evolution was not unfavourable: vital capacity increased by 8%+/-20% and FEV1 remained stable (mean change 0.3%+/-12%). Only 2 patients had an unfavourable evolution.

CONCLUSION

At time of diagnosis, patients with primary ciliary dyskinesia have partially reversible obstructive airway disease. During regular follow up and therapy, there is no evidence of a further decline in lung function. Patients with associated immunodeficiency or important damage at the start of therapy may have a worse prognosis.

No paradoxical bronchodilator response with forced oscillation technique in children with cystic fibrosis

STUDY OBJECTIVES

The aim of the present study was to evaluate the forced oscillation technique (FOT) in cystic fibrosis (CF) children and to participate in the discussion about the usefulness of beta2-antagonists in CF.

DESIGN

Pulmonary function was measured with spirometry, body plethysmography, and FOT before and after inhalation of 200 microg of albuterol (salbutamol). The following were collected: vital capacity (VC), FEV1, FEV1/VC, airway resistance (Raw), thoracic gas volume, respiratory system resistance (Rrs) and respiratory system reactance (Xrs) at 6 Hz (Rrs6 and Xrs6), and resonance frequency.

SETTING

The study was set up at a university hospital with a CF population of 125 children and adolescents.

PATIENTS

Data were collected on 20 patients in stable condition able to perform the three lung function tests.

MEASUREMENTS AND RESULTS

Mean baseline values (+/-SD) were 0.36+/-0.15 kPa/L/s for Raw, 0.5+/-0.15 kPa/L/s for Rrs6, and 61+/-22% predicted for FEV1. The relationship between FEV1 and Raw or Rrs6 was poor. Xrs6 and FEV1/VC correlated weakly (r=0.56; p < 0.05). After bronchodilator administration, the mean changes +/-SD in percent of baseline were +3 +/- 11% for FEV1, -16 +/- 22% for Raw, and -16 +/- 9% for Rrs6. In six patients, a paradoxical decrease in FEV1 was measured but an increase in Rrs6 was never found; in two patients, an increase of Raw of < 10% was found. In 13 patients, the decrease of Rrs6 was > 12%.

CONCLUSIONS

The results suggest that FOT measurements cannot replace baseline spirometric measurements in CF, but that the evaluation of the effect of beta2-agonists on the airway diameter in CF should include an FOT measurement.

Bronchial constriction after nebulized tobramycin preparations and saline in patients with cystic fibrosis

To assess the airway response to inhaled tobramycin we measured flow volume curves in 12 patients with cystic fibrosis. Immediately and/or 2 min after tobramycin inhalations there was a significant fall in lung function regardless of the concentration used; isotonic saline caused similar obstruction but not a complete cessation of peripheral airflows. The baseline oxygen saturation was significantly correlated with the fall in lung function. Ten minutes after inhalation lung function tests returned to baseline values.

CONCLUSION

As salbutamol could significantly reduce airway obstruction tobramycin should always be inhaled in combination with a bronchodilator.

Obstructive lung disease and sleep

There is a significant interaction between obstructive lung disease and sleep--sleep is associated with clinical deterioration in obstructive lung disease, and vice versa. Knowledge of the pathophysiology of deterioration in obstructive lung disease during sleep is essential to the understanding of the management of this problem. Recent information has helped to clarify this pathophysiology and has led to more aggressive treatment for deterioration of obstructive lung disease during sleep. Whether this newer and more aggressive treatment strategy improves survival or morbidity in these conditions is a challenge for future research.

Cystic fibrosis--an Indian perspective on recent advances in diagnosis and management

Cystic fibrosis (CF) is a common inherited disorder in caucasians. The estimated incidence of CF in Asians varies from 1:10,000 to 1:12,000. Indian data is restricted to few case reports. The gene for CF is located on the long arm of chromosome 7 at position 7q13. There are more than 300 identified mutations in CF. The basic defect in CF is a mutational change in the gene for chloride conductance channel. Failure of chloride conductance by epithelial cells leads to dehydration of secretions that are too viscid and difficult to clear. The disease is characterized by abnormal secretions in the respiratory, gastrointestinal and reproductive tract and sweat glands. The common clinical manifestations include meconium ileus in neonatal period, recurrent lower respiratory tract infections (pseudomonas pneumonia, bronchiectasis), steatorrhoea, azoospermia, and in late stages hepatobiliary and endocrine pancreatic dysfunctions. The diagnosis of disease is established by clinical criteria and sweat chloride concentration more than 60 mEq/L. Facilities for DNA diagnosis of common CF mutations are now available in India. The treatment of CF includes early diagnosis, daily clearance of respiratory passages, appropriate antibiotic therapy, aerosolised recombinant human DNase and antibiotics, and nutritional supplementation. The latter include changes in diet composition, pancreatic enzyme supplementation and vitamins and trace mineral supplementation. Gene therapy for the pulmonary manifestations is being tried in a number of centres abroad. Other considerations include heart lung transplantation and ameloride inhalation therapy.

Increased physiological dead space during exercise after bronchodilation in cystic fibrosis

Bicycle ergospirometry was performed on 14 patients with cystic fibrosis (CF), for evaluating the effects of salbutamol and theophylline on the ventilatory response to exercise. After 1 week without bronchodilator therapy the patients cycled at 1/3 and 2/3 of their individual maximal working capacity (Wmax). The test was repeated three times after treatment with salbutamol, theophylline, or both drugs, respectively. After the combined therapy, physiological deadspace, ventilation, ventilatory equivalent of oxygen, and end-expiratory oxygen pressure increased significantly during steady state exercise at 1/3 Wmax. Similar, although not statistically significant changes, were observed after monotherapy with salbutamol or theophylline and during exercise at 2/3 Wmax. These effects could not be predicted by any lung function tests at rest or by the Shwachman-Kulczycki score. The results indicate that in some patients with CF bronchodilators can impair lung function during exercise. In conclusion, the effects of medication on exercise performance of patients with CF have to be considered. Especially, the use of bronchodilators requires a careful evaluation of their real benefit in each individual patient.

Self-administered chest physiotherapy in cystic fibrosis: a comparative study of high-pressure PEP and autogenic drainage

Fourteen patients with cystic fibrosis were trained in 2 self-administered chest physiotherapy (PT) techniques: high-pressure PEP-mask physiotherapy (PEP), and autogenic drainage (AD). They then visited the clinic on 5 consecutive days, and, in a random order, performed 1 of the following: PEP, AD, PEP followed by AD (PEP-AD), AD followed by PEP (AD-PEP), and, no PT except for spontaneous coughing. Lung function was measured repeatedly before, during, and after PT; time needed for and sputum produced by each form of PT was recorded. PEP produced the highest amount of sputum, followed by PEP-AD, AD-PEP, and AD; all 4 forms of PT produced significantly more sputum than coughing. Lung function improved significantly after PEP, AD, and PEP-AD, but PEP-induced changes did not exceed those after AD. Within the investigated group, the PEP-induced lung function improvement per milliliter of sputum produced was significantly lower for those patients with airway hyperreactivity. The fact that the highest sputum yield with PEP was not reflected in higher PEP-effected lung function changes might thus be explained by PEP-induced bronchospasm in patients with airway hyperreactivity. PEP clears more sputum than AD or combined techniques; patients with airway hyperreactivity, however, should either prefer AD or should take a bronchodilator premedication before PEP.

Nonhomogeneous lung emptying in cystic fibrosis patients. Volume history and bronchodilator effects

In spontaneous asthma after a deep inhalation (DI) obstruction occurs in direct proportion to disease severity. Since this has been associated with peripheral inflammation, which is present in cystic fibrosis (CF), we tested whether worsening obstruction after DI also occurs in CF in 12 patients. We assessed volume history effects by comparing isovolumic expiratory flows (Vmax) during forced exhalation begun at the end of tidal inspiration (partial P) with those begun at TLC (maximal M) to obtain M/P. As in asthma there was a correlation between M/P and FEV1 (% predicted; r = 0.64, p less than or equal to 0.03, n = 12). To control for a time dependency effect due to preferential emptying of fast compartments early in both the P and M maneuvers, we compared Vmax obtained from a first partial (P1) with a second (P2) obtained after inspiration to TLC and slow exhalation to the same starting volume as P1 (P2/P1). In contrast to asthma the P2/P1 was greater than the M/P and not related to disease severity. A further index of nonhomogeneous lung emptying was the relationship between M/P and the slope ratio at 70% TLC (r = -0.67, p less than or equal to 0.03). After isoetharine inhalation the M/P decreased (-0.12 +/- 0.12, p less than or equal to 0.01) but no change was apparent in P2/P1, indicating further increases in the degree of nonhomogeneity. We conclude that although volume history effects on M/P are similar in asthma and CF, this is due to a predominance of parenchymal hysteresis in the former and nonhomogeneity in the latter, which worsens with bronchodilator use.

Changes in airflow obstruction and oxygen saturation in response to exercise and bronchodilators in cystic fibrosis

The airway response to exercise and inhaled terbutaline was assessed in 25 patients with cystic fibrosis (CF), seeking evidence for the possible deleterious effects of bronchial muscle relaxation. We postulated that "early" and "late" flows, taken from the full maximum expiratory flow volume curve, might move paradoxically in patients with unstable airways. Oxygen saturation was measured continuously; desaturation occurred early in exercise with partial recovery thereafter. This was unrelated to changes in expiratory airflow measurements. Both during and after exercise, and after inhaled bronchodilator, changes in expiratory airflow measurements were strikingly variable. Changes in individual measurements should be interpreted in relationship to the within-subject variability of the test in patients with CF. During exercise, there was a significant increase in mean FEV1; this was most marked in patients with worst lung function. Two patients (both with severe lung disease) showed paradoxical changes in early and late flows. After exercise, only two patients showed the asthmatic pattern of postexercise bronchoconstriction. After inhaled bronchodilator, the group as a whole showed small but statistically significant increases in expiratory airflow measurements. Those with highest baseline FEV1 had the greatest bronchodilator response; this is the opposite of the pattern observed in asthma. Paradox did not occur after bronchodilators and only one patient showed a significant fall in late expiratory airflow. This pattern of expiratory airflow changes is compatible with the concept of airway instability in which any beneficial effects of bronchial tone reduction are canceled out by the effects of compression of damaged airways rendered more compliant by loss of bronchial wall tone. We did not observe any clinically important deleterious effects from this mechanism.