Effect of physiotherapy on pulmonary function. A laboratory study

Physiotherapy management of acute exacerbations of chronic obstructive pulmonary disease

[Holland AE (2014) Physiotherapy management of acute exacerbations of chronic obstructive pulmonary disease.Journal of Physiotherapy60: 181-188].

Impact of the prolonged slow expiratory maneuver on respiratory mechanics in wheezing infants

OBJECTIVE:

To evaluate changes in respiratory mechanics and tidal volume (V_T) in wheezing infants in spontaneous ventilation after performing the technique known as the prolonged, slow expiratory (PSE) maneuver.

METHODS:

We included infants with a history of recurrent wheezing and who had had no exacerbations in the previous 15 days. For the assessment of the pulmonary function, the infants were sedated and placed in the supine position, and a face mask was used and connected to a pneumotachograph. The variables of tidal breathing (V_T and RR) as well as those of respiratory mechanics-respiratory system compliance (Crs), respiratory system resistance (Rrs), and the respiratory system time constant (prs)-were measured before and after three consecutive PSE maneuvers.

RESULTS:

We evaluated 18 infants. The mean age was 32 ± 11 weeks. After PSE, there was a significant increase in V_T (79.3 ± 15.6 mL vs. 85.7 ± 17.2 mL; p = 0.009) and a significant decrease in RR (40.6 ± 6.9 breaths/min vs. 38.8 ± 0,9 breaths/min; p = 0.042). However, no significant differences were found in the variables of respiratory mechanics (Crs: 11.0 ± 3.1 mL/cmH₂O vs. 11.3 ± 2.7 mL/cmH₂O; Rrs: 29.9 ± 6.2 cmH₂O • mL⁻¹ • s⁻¹ vs. 30.8 ± 7.1 cmH₂O • mL⁻¹ • s⁻¹; and prs: 0.32 ± 0.11 s vs. 0.34 ±0.12 s; p > 0.05 for all).

CONCLUSIONS:

This respiratory therapy technique is able to induce significant changes in V_T and RR in infants with recurrent wheezing, even in the absence of exacerbations. The fact that the variables related to respiratory mechanics remained unchanged indicates that the technique is safe to apply in this group of patients. Studies involving symptomatic infants are needed in order to quantify the functional effects of the technique.

Airway clearance techniques for chronic obstructive pulmonary disease

BACKGROUND

Cough and sputum production are common in chronic obstructive pulmonary disease (COPD) and are associated with adverse clinical outcomes. Airway clearance techniques (ACTs) aim to remove sputum from the lungs, however evidence of their efficacy during acute exacerbations of COPD (AECOPD) or stable disease is unclear.

OBJECTIVES

To assess the safety and efficacy of ACTs for individuals with AECOPD and stable COPD.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials from inception to October 2011, and PEDro in October 2009.

SELECTION CRITERIA

We included randomised parallel trials and randomised cross-over trials which compared an ACT to no treatment, cough or sham ACT in participants with investigator-defined COPD, emphysema or chronic bronchitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and assessed the risk of bias. We analysed data from studies of AECOPD separately from stable COPD, and classified the effects of ACTs as 'immediate' (less than 24 hours), 'short-term' (24 hours to eight weeks) or 'long-term' (greater than eight weeks). One subgroup analysis compared the effects of ACTs that use positive expiratory pressure (PEP) to those that do not.

MAIN RESULTS

Twenty-eight studies on 907 participants were included in the review. Study sample size was generally small (range 5 to 96 people) and overall quality was generally poor due to inadequate blinding and allocation procedures. Meta-analyses were limited by heterogeneity of outcome measurement and inadequate reporting of data.In people experiencing AECOPD, ACT use was associated with small but significant short-term reductions in the need for increased ventilatory assistance (odds ratio (OR) 0.21, 95% confidence interval (CI) 0.05 to 0.85; data from four studies on 171 people), the duration of ventilatory assistance (mean difference (MD) -2.05 days, 95% CI -2.60 to -1.51; mean duration for control groups seven days; data from two studies on 54 people) and hospital length of stay (MD -0.75 days, 95% CI -1.38 to -0.11; mean duration for control groups nine days; one study on 35 people). Data from a limited number of studies revealed no significant long-term benefits of ACTs on the number of exacerbations or hospitalisations, nor any short-term beneficial effect on health-related quality of life (HRQoL) as measured by the St. George's Respiratory Questionnaire (SGRQ) total score (MD -2.30, 95% CI -11.80 to 7.20; one study on 59 people).In people with stable COPD, data from single studies revealed no significant short-term benefit of ACTs on the number of people with exacerbations (OR 3.21, 95% CI 0.12 to 85.20; one study on 30 people), significant short-term improvements in HRQoL as measured by the SGRQ total score (MD -6.10, 95% CI -8.93 to -3.27; one study on 15 people) and a reduced long-term need for respiratory-related hospitalisation (OR 0.27, 95% CI 0.08 to 0.95; one study on 35 participants).The magnitude of effect of PEP-based ACTs on the need for increased ventilatory assistance and hospital length of stay was greater than for non-PEP ACTs, however we found no statistically significant subgroup differences. There was one report of vomiting during treatment with postural drainage and head-down tilt.

AUTHORS' CONCLUSIONS

Evidence from this review indicates that airway clearance techniques are safe for individuals with COPD and confer small beneficial effects on some clinical outcomes. Consideration may be given to the use of airway clearance techniques for patients with COPD in both acute and stable disease, however current studies suggest that the benefits achieved may be small.

Effect of respiratory muscle training on pulmonary function in preoperative preparation of tobacco smokers

PURPOSE: To evaluate the effect of utilization of a specific training program of respiratory muscles on pulmonary function in tobacco smokers. METHODS: Fifty asymptomatic tobacco smokers with age superior to 30 years were studied, at the moments: A0 - initial evaluation followed by protocol of respiratory exercises; A1 - reevaluation after 10 minutes of protocol application; and A2 - final reevaluation after 2 weeks of training utilizing the same protocol 3 times per week. The evaluation was realized through measures of maximum respiratory pressures (PImax and PEmax), respiratory peak flow (IPF and EPF), maximum voluntary ventilation (MVV), forced vital capacity (FVC) and forced expiratory volume at the 1st second (FEV1). RESULTS: There was no improvement from initial to final evaluation in FVC and FEV1. But there were significant increases in the variables IPF, EPF, MVV and PImax at evaluations A1 and A2. The PEmax variable increased only at evaluation A2. CONCLUSION: The application of the protocol of respiratory exercises with and without additional load in tobacco smokers produced immediate improvement in the performance of respiratory muscles, but this gain was more accentuated after 2 weeks of exercise.

Effective physical therapy for chronic obstructive pulmonary disease. Pilot study of exercise in hot spring water

Respiratory function and arterial blood gas were examined before and after a two-month exercise program performed in a pool filled with hot spring water in 22 patients (70.9 +/- 9.1 years of age) with stable chronic obstructive pulmonary disease (12 cases of bronchial asthma and 10 cases of pulmonary emphysema) treated at our hospital between 1991 and 1994. The ratio of forced expired volume in one second to forced vital capacity (FEV1%) was significantly increased after the exercise program (P < 0.05), whereas the ratio of forced vital capacity to predicted normal value (%FVC) did not change. In addition, a tendency toward an increase in peak flow without an increase in maximum expiratory flow at 25 and 50% (V25 and V50) was observed. Although PaO2 was not increased, PaCO2 was selectively decreased by the exercise program (P < 0.05). The changes in respiratory function and arterial blood gas were considered attributable to respiratory muscle training and small airway clearance. Exercise in a pool filled with hot spring water may be useful in treating chronic obstructive pulmonary disease.

Maximum expiratory airflow during chest physiotherapy on ventilated patients before and after the application of an abdominal binder

Chest physiotherapy using a manual ventilation technique was carried out on 9 intubated patients. One patient was studied on two occasions. The maximum expiratory flow rate (MEFR) was recorded during: (A) manual ventilation without physiotherapy, (B) manual ventilation with chest compression, (C) manual ventilation and chest compression, after application of the abdominal binder. Statistical analysis was carried out to allow for differences in tidal volume (Vt). Chest physiotherapy increased the mean MEFR and application of an abdominal binder (together with physiotherapy) caused a further increase in MEFR. The mean MEFR (assuming a common Vt of 1360 ml) in each group was; (A) = 73.3 l min-1, (B) = 103.9 l min-1, (C) = 113.93 l min-1.

Chest physiotherapy. Evaluation by transcutaneous blood gas monitoring

Two respiratory physiotherapy methods were evaluated by analyzing changes in the transcutaneous partial pressure of CO2 (tcPCO2) in 15 patients with respiratory insufficiency. All were receiving continuous oxygen therapy and had CO2 retention. The physiotherapy methods compared were thoracic compression (TC) and positive expiratory pressure (PEP). The mean decrease (+/- SD) in tcPCO2 was the same with both methods, 0.6 +/- 0.4 kPa, but there were interindividual differences. This study indicates that both TC and PEP effectively decrease tcPCO2, although only temporarily in many cases. Continuous tcPCO2 monitoring is a useful clinical method for determining and teaching optimal respiratory therapy.

Chest physiotherapy: time for reappraisal

Chest physiotherapy should now be updated with attention to three important features: first, its use should be limited to those patients with actual or potential sputum production and its central aim should be to increase expectoration. Second, it should incorporate the forced expiration technique with postural drainage and omit traditional elements such as percussion and vibration. Third, the additional use of inhaled adrenergic agents and possibly oral high frequency oscillation may increase sputum clearance further.

Effect of manual percussion on tracheobronchial clearance in patients with chronic airflow obstruction and excessive tracheobronchial secretion

The effect of manual percussion of the thorax in nine patients with stable chronic airflow obstruction and excessive tracheobronchial secretion has been studied. Tracheobronchial clearance was measured over 50 minutes on three different days. On the first day manual percussion was applied for 10 minutes. In the period when percussion was applied the mucus clearance was slightly but significantly greater than in the periods when no percussion was applied. On the second day manual percussion was applied in combination with postural drainage, coughing, and breathing exercises for 20 minutes. This resulted in a much greater clearance than on the first day. On the third day postural drainage, coughing, and breathing exercises, but no manual percussion, were carried out for 20 minutes. There was no significant difference between the clearance of days 2 and 3. From this study it is apparent that manual percussion is a relatively ineffective procedure in patients with stable chronic airflow obstruction, but may be useful when the patient is not able to cough and cannot assume the appropriate position for postural drainage.

Does chest physical therapy work?

Postural drainage has usually been shown to be an effective component of chest physical therapy; there is currently no data showing a beneficial effect of percussion or vibration; directed coughing may be as efficacious as postural drainage (Table 3); the forced expiration technique may increase sputum clearance with or without postural drainage (Table 4).

Chest percussion and postural drainage in patients with bronchiectasis

Patients with chronic obstructive pulmonary disease have been treated routinely with chest physical therapy for many years in spite of a lack of scientific validation of this procedure. Only recently have the indications for chest physical therapy been clarified. It is currently believed that such therapy is especially beneficial in patients with copious secretions, and that it is less effective in patients with scanty secretions. No study has specifically evaluated the efficacy of chest physical therapy in patients with bronchiectasis. We accordingly evaluated 13 patients with stable bronchiectasis to determine the effects of chest physical therapy on pulmonary function, arterial oxygenation, and sputum production and to assess whether this therapy was associated with any significant side-effects. We found that chest physical therapy was safe and well tolerated and assisted the patients in mobilization of their sputum. However, such therapy had no immediate delayed effects on pulmonary function or oxygen saturation.

Therapy of chronic obstructive airways disease

The most frequently employed measure in attempts to alleviate symptoms and improve the quality of life of patients with chronic obstructive airways disease (COAD) is to prescribe medications. However, COAD is largely an irreversible condition and no therapeutic intervention has been shown to be universally useful. Theophylline or corticosteroid are occasionally helpful but most patients will not benefit. Of the remaining options, only oxygen has been shown to be effective in selected patients and should be administered on a continuous basis. It is becoming increasingly evident that clinicians should be more discriminating when making therapeutic decisions for persons with COAD. Maintenance therapy with pharmacological agents should be entertained only after individually conducted therapeutic trials. Moreover, enormous costs can result from treating even a small fraction of the population estimated to have COAD.

Immediate and long-term effects of chest physiotherapy in patients with cystic fibrosis

Both the immediate and long-term effects of chest physical therapy administered by a parent were evaluated in eight children with cystic fibrosis. Spirometric and plethysmographic evaluations were performed pre-CPT and at 5 and 30 minutes post-CPT. The pre-CPT measurements after a three-week period with no CPT were compared with the values while receiving CPT on a regular twice daily basis. There was a significant decrease after three weeks without CPT for FVC (P less than 0.025), FEV1 (P less than 0.005), FEF25-75 (P less than 0.005), and Vmax60TLC (P less than 0.025). When the patients had been receiving CPT on a regular basis, the only immediate effect was an increase in PEFR after 30 minutes post-CPT (P less than 0.05). After three weeks without CPT, there were increases at 30 minutes post-CPI for FVC (P less than 0.005) and Vmax60TLC (P less than 0.05). These findings indicate that although there may be little immediate functional improvement when CPT is received on a regular basis, a three-week period without CPT leads to a worsening of the functional status, which is reversed with renewal of regular CPT.

Is cough as effective as chest physiotherapy in the removal of excessive tracheobronchial secretions?

The relative value of chest physiotherapy (including cough) and cough alone for the removal of excessive tracheobronchial secretions has been assessed in six patients with stable chronic obstructive lung disease. After labelling with inhaled radioactive tracer particles, clearance of secretions from selected central and peripheral lung regions was followed with a gamma camera linked to a computer. Cough alone and chest physiotherapy (including cough) were equally effective in the enhancement of central lung clearance. Physiotherapy but not cough along accelerated peripheral lung clearance (p less than 0.05). Sputum yield was greater during physiotherapy than during cough (p less than 0.05). These findings confirm the value of chest physiotherapy and high-light the limitation of cough in patients with excessive tracheobronchial secretion and impaired mucociliary clearance.

Chest physical therapy. The immediate effect on oxygenation in acutely ill patients

There is no documentation in the literature of the risk of hypoxemia after chest percussion in acutely ill adults with nonsurgical pulmonary disorders. We studied the immediate effect of postural drainage and chest percussion (PDP) on oxygenation in 22 hospitalized patients with a variety of acute, nonsurgical pulmonary disorders. Heart rate, respiratory rate, blood pressure, and arterial blood gas levels were measured at four points before, during, and after PDP. There was a significant fall in PaO2 after chest percussion in ten patients who produced no sputum or small amounts of mucoid sputum. The mean PaO2 fell 16.8 mm Hg (P < 0.05) immediately after PDP, when compared to the value obtained after postural drainage alone, and had fallen another 5.3 mm Hg (P < 0.01) 30 minutes after return to the pretreatment position. There was no significant change in PaO2 in 12 patients who produced moderate to large amounts of mucopurulent secretions. The fall in PaO2 was probably due to increased ventilation-perfusion mismatch since this fall was avoided in two patients restudied while receiving 100 percent oxygen. We concluded that all acutely ill patients receiving PDP should be carefully monitored and, if necessary, should receive increased levels of inspired oxygen to avoid hypoxemia. Our data suggest that the use of PDP in patients without sputum production is not indicated and is potentially dangerous.

Regional lung clearance of excessive bronchial secretions during chest physiotherapy in patients with stable chronic airways obstruction

Clearance of excessive bronchial secretions labelled with inhaled radioactive polystyrene particles has been directly measured with a gamma-camera linked to a computer. Chest physiotherapy significantly increased clearance from central, intermediate, and peripheral lung regions and sputum yield. These findings confirm the value of this form of treatment, which has hitherto been in doubt, in removing excessive bronchial secretions from all lung regions and in aiding their expectoration.