Chest Physiotherapy or Techniques in Cardio-pulmonary Physiotherapy?

Introduction

Any individual with respiratory symptoms may be considered for chest physiotherapy. Patients requiring chest physiotherapy usually fall into two categories of lung diseases: restrictive lung disease and obstructive lung disease. Patients with restrictive lung diseases presents with inadequate volumes and capacities, where inadequate volumes inhibit ventilation due to activity. Patients with obstructive lung diseases present with breathlessness due to reduced flow rates, where they cannot exhale sufficiently to meet activity or exercise demands.

Patients with respiratory symptoms presents with any of the following problems or in combination of the same. The problems usually are loss of lung volumes, increased work of breathing with breathlessness and difficulty to mobilize and remove secretions. One may observe that the above problems are related or one may lead to the other and therefore present as a vicious cycle. A patient who presents with loss of lung volumes will sooner develop breathlessness with increased work of breathing and later develops secretions which need to be cleared. Another patient with uncleared secretion will soon develop loss of lung volumes and later develop breathlessness with increased work of breathing. A proper identification of patient’s specific respiratory problem is useful to design a treatment program that meets the patient’s needs. This is possible only by thorough assessment.

For chest physiotherapy to make a difference, a thorough assessment will help generate the problem list to prioritize the objectives and goals. As an unwritten rule, patients with restrictive lung disease who presents with inadequate volumes and capacities may require methods and techniques to increase lung volumes and clear secretions. Similarly, patients with obstructive lung diseases who presents with breathlessness due to reduced flow rates may require methods and techniques to decrease work of breathing.

Conventionally, chest physiotherapy in the form of postural drainage, percussion and vibrations are routinely carried out by physiotherapists or respiratory therapists to remove secretions, thereby improving respiratory function and preventing collapse of the lung.^1,2 Not all the patients referred for chest physiotherapy require secretion removal as some patients may require management of breathlessness and others may require re-expansion of lungs. Hence, cardiopulmonary physiotherapy techniques were evolved. The techniques thus evolved facilitated removal of secretions and even included techniques to improve lung volumes and capacities and techniques to reduce work of breathing. Even though breathing techniques and breathing exercises are different, these terms were interchangeably used in the literature and practiced. Hence, this commentary gives insight to these issues. Here the authors described in brief different techniques which are available in the literature. This is even applicable to Corona Virus disease (COVID) management at various stages, such as acute COVID, post-acute COVID (now called as ongoing symptomatic COVID) and long COVID, considering severity such as mild, moderate, severe or critical. Not all patients should be treated with the same technique; rather techniques should be administered based on thorough assessment and clinical decision making.³

Traditional Chest Physical Therapy (CPT or Chest PT) is a type of respiratory care which is used as an airway clearance technique (ACT) to drain the lungs. It includes positioning, postural drainage, percussion (clapping), vibration, deep breathing, and huffing or coughing.^4,5

Cardio-pulmonary physiotherapy techniques can be applied for the treatment of wide range of patients with acute and chronic lung diseases, but then again effective in patients with advanced neuromuscular disorders, patients admitted for major surgeries (cardiac, thoracic & abdominal) and patients in the intensive care unit. The aim is to manage breathlessness, symptom control, mobility & function improvement or maintenance, and airway clearance & cough enhancement or support. Strategies and techniques include, rehabilitation, exercise testing & prescription, airway clearance, positioning and breathing techniques or exercise.

Techniques in Cardiopulmonary Physiotherapy

Reduced lung expansion, accumulation of secretions and increased work of breathing are the main problems seen with cardio-respiratory disorders. Physiotherapists use Lung expansion therapy, Bronchial hygiene/ Airway clearance therapy and techniques to reduce work of breathing.⁶

Lung expansion therapy

techniques are advised in patients with decrease or loss of lung volume. Loss of lung volume takes a variety of forms. In atelectasis, there is anatomical and physiological loss of lung volume, whereas in consolidation, there is only physiological loss of lung volume. It improves transpulmonary pressure gradient, improves air entry through collateral channels and through the physiology of interdependence. Lung expansion therapy techniques are administered based on the level of consciousness. It includes positioning, mobilization, breathing techniques, neurophysiologic facilitation of respiration and use of mechanical aids such as Incentive spirometer, Continuous positive airway pressure (CPAP), Bilevel positive airway pressure (Bi PAP) etc.^7,8,9 Patients are instructed to take ten spirometry breaths per waking hour. Third ball in the triflo spirometer should not be lifted as it is a control and if lifted, it indicates high flow and turbulence of airway.^6,7 As it uses the principle of sustained maximal inspiration, it is used only for inspiratory exercises. As there is no justified evidence showing any beneficial effect, and considering the principle of incentive spirometer, it is suggested not to use it in reverse position.

Secretion clearance

is required when there is inadequate mucociliary function, impaired cough reflex and excessive secretion production. Mucociliary transport is impaired by cigarette smoking, anaesthetics, analgesics, hypoxia or hypercapnia, dehydration, electrolyte imbalance, inhalation of dry gases, pollutants and a cuffed endotracheal tube. Cough can be affected by pain, weakness, or in-coordination of the ventilator muscles. Excessive secretions are typically seen in chronic bronchitis, asthma, bronchiectasis, cystic fibrosis, and sometimes infection. Airway clearance techniques involves physical or mechanical means of facilitating the removal of secretions through external and/or internal manipulation of air flow, and the clearance of secretion via coughing. So these techniques are used to mobilize and remove secretions and improve gas exchange. This includes traditional methods such as early mobilisation, positioning, postural drainage, chest manipulations such as percussions, vibrations & shaking, breathing strategies such as active cycle breathing technique & autogenic drainage, use of mechanical devices such as flutter, acapella, positive expiratory pressure mask, cornett, intrapulmonary percussive ventilator, mechanical insufflator–exsufflator, High-frequency chest wall compressions (HFCWC) etc. Patients presenting with non-productive cough or those in the early stages of consolidation, airway clearance techniques are not recommended. ⁶

Work of breathing (WOB) is defined as the amount of pressure generated to move a certain volume of gas. Increased work of breathing in spontaneously breathing patient is manifested subjectively by breathlessness and objectively by a distressed breathing pattern. The basic principle of reducing the WOB is to optimize the balance between energy supply and demand. The basic techniques involve positioning, relaxation, breathing control techniques, and the use of mechanical aids such as CPAP and BiPAP etc.^6,7

Another problem seen in cardio-pulmonary patients is progressively reduced activity. A vicious cycle develops of inactivity, reduced muscular inefficiency causing increasing symptomatology and further abatement of activity in order to avoid discomfort. Exercise tolerance can be improved by aerobic conditioning. Exercise conditioning can be achieved by lower limb training, upper limb training or combined. For lower limb training, walking and cycling is preferred. For combined training, daily swimming, rowing or canoeing is preferred. Upper limb training is given in both obstructive disorders and restrictive disorders. For upper limb training, supported exercise training is given during acute exacerbation of chronic obstructive pulmonary disease and asthma, while unsupported arm training is given during stable phase. ^6,10

Another difficulty that might be encountered in patients with cardiopulmonary dysfunction is abnormal physiologic response to increasing activity. Common abnormalities include excessive increase in heart rate, blunted blood pressure responses, irregularities of pulses, increase in respiratory rate, oxygen de-saturation etc. The appropriate therapeutic intervention for this problem is continued clinical monitoring to allow as much activity as possible, while still maintaining patient safety. It is also important to instruct the patient in self monitoring of exercise intensity using pulse rate and rhythm, RPE and symptoms.

Some patients with chronic diseases become so debilitated that they are unable to meet the physical demands of various activities of daily living that are required to perform for independence. These patients can be taught energy conservation techniques and work simplification techniques which reduces demands of the activities they must perform.⁶

Breathing Exercises Versus Techniques

Breathing exercises/ techniques have been a common terminology used to improve lung expansion, to clear secretion and to reduce work of breathing. However, one must note that breathing control techniques are done at almost normal breathing volumes. Whereas in breathing exercises, either inspiration is stressed (eg: thoracic expansion exercises) or expiration is stressed (eg: stressed expiratory exercises or huff). In breathing control technique, minimal effort is expended and the focus is on energy conservation, whereas in breathing exercise, there is maximal effort expended.

Classification

Breathing exercises which are inspiratory stresses inspiration, thereby increasing lung volume, while breathing exercises which are expiratory stresses on expiration. Expiratory breathing exercises aids in clearance of secretions.

Breathing exercises such as deep diaphragmatic breathing which uses the principle of slow maximal inspiration, breathing with hold at end inspiration, incentive spirometer which uses the principle of sustained maximal inspiration, sniff, segmental breathing exercises for various broncho-pulmonary segments are commonly used. In case of spinal cord injuries, abdominal or air shift or glossopharyngeal are commonly used. Stacked breathing is used in localized atelectasis of any of the zones and air-shift breathing is used in generalized atelectasis. In order to prevent the formation of adhesions between pleural layers, chest mobility exercises and belt exercises are administered.

Airway clearance techniques or bronchial hygiene therapy includes breathing strategies such as autogenic drainage (AD) and active cycle breathing technique (ACBT). Once these techniques are taught, they can be done at home independently and most suited for chronic lung disease.

Reduced flow rate, increase in residual volume and total lung capacities are the problems associated with obstructive lung diseases. As these patients use accessory muscles, work of breathing is increased. Therefore, the management includes altering the breathing pattern, to reduce work of breathing and to use energy conservation techniques. Initially patients have a period of acute exacerbation and later they will be in their stable phase. During breathlessness or during acute exacerbation, Breathing Control Technique, Innocenti Technique, and Pursed Lip Breathing can be administered. Diaphragmatic breathing exercise is not recommended during breathlessness period; instead diaphragmatic breathing with normal tidal volume which is called as breathing control is administered. During stable phase, End – Expiratory, Buteyko Breathing, Exhale with Activity, Stressed Respiratory Exercises, Panting, Pacing are frequently administered. Respiratory muscle training can be administered which includes inspiratory muscle training and expiratory muscle training. Inspiratory muscle training includes inspiratory threshold training, inspiratory resistive training and isocapneic hyperpneic ventilation training. In subjects with chronic hyperventilation syndrome (there are no organic causes for breathlessness), breathing cycle technique is commonly administered. These subjects during hyperventilation has low levels of CO2 which produces systemic effects such as palpitation, tachycardia, breathlessness, dysphagia, dizziness muscle pain, head ache etc.^6,11

Conclusion

Not all the patients referred for chest physiotherapy require secretion removal as some patients may require management of breathlessness and others may require re-expansion of lungs. Not all patients should be treated with same techniques; rather techniques should be administered based on thorough assessment and clinical decision making. Conflicts of interest Declared.