Airway clearance therapy

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Airway clearance therapy

Airway clearance therapy is treatment that uses a number of airway clearance techniques to clear the respiratory airways of mucus and other secretions. [1] Several respiratory diseases cause the normal mucociliary clearance mechanism to become impaired resulting in a build-up of mucus which obstructs breathing, and also affects the cough reflex. Mucus build-up can also cause infection, and inflammation, and repeated infections can result in damage to the airways, and the lung tissue. [1] [2]

Contents

All airway clearance therapy involves the techniques of coughing, or huffing that need to be used in conjunction with another airway clearance technique. [3] Respiratory therapists make recommendations and give guidance for appropriate airway clearance therapies. They also give instruction in the use of various airway clearance techniques.

Clearance techniques

Airway clearance therapy uses different airway clearance techniques (ACTs) in a number of respiratory disorders including, cystic fibrosis, bronchitis, bronchiectasis, and chronic obstructive pulmonary disease to maintain respiratory health, and prevent the damaging consequences of inflammation. [4] [1] [2] Techniques used are breathing, manual, and mechanical. [5] They all need to be used with either coughing or huffing which moves mucus from the large airways. [3] To move mucus from the small airways an additional ACT needs to be employed.

Breathing

Breathing techniques include the active cycle of breathing which includes huffing; and autogenic drainage, a technique that requires concentrated effort. [1]

Huffing

Huffing or a huff cough, is also called forced expiration technique, and helps to move mucus away from the lung wall so that it can finally be coughed out. Huffing needs to be carried out in a sitting position with the chin raised a little, and the mouth remaining open. A deep breath is taken to fill the lungs about 75 per cent, and held for two or three seconds. Breathing out is forceful and slow which helps to move the mucus from the smaller to the larger airways. A normal urge to cough at this point is repressed, and the breathing pattern is repeated a few times. A strong cough then follows to expel the mucus. [3] Huffing forms part of the active cycle of breathing. Huffing as a clearance technique is different to the term of huffing used in substance inhalation.

Active cycle of breathing

The active cycle of breathing technique is carried out in three phases. Phase one is used to relax the airways; phase two involves moving the inhaled air to behind the mucus in order to clear it; phase three helps to clear the mucus out from the lungs. [6]

Phase one

Gentle effortless breathing, in through the nose, and out through the mouth is used in phase one to relax the airways. The shoulders and upper chest are kept relaxed. On breathing out, the pursed lips method is advised. Keeping the lips pursed (as in kissing somebody) when exhaling creates a back pressure that keeps the airways open for longer. One recommendation is for six breaths of control to take place before phase two of the cycle. [6]

Phase two

Phase two involves using exercises to expand the chest. Breathing is deep and may use a breath-hold of three seconds to move the air into the smaller airways, and reach behind the mucus. The out breath is unforced and may include some percussive clapping, or vibration. [6]

Phase three

Using huffing coughing, mucus is moved from the smaller airways to the larger airways, and huffing needs to be continued until all the mucus is expelled. [6]

Autogenic drainage

Autogenic drainage is a controlled airway clearance technique using different depths of inhalation, and different speeds of exhalation that enables mucus to be moved up the airway producing a voluntary cough. This method does not require any equipment, however, it is challenging to perform and appropriate training is required. [2] Evidence supporting different techniques is limited. A review of the studies that have been conducted concluded that there is no strong evidence that autogenic drainage is better than other airway clearance techniques. [2]

Manual

Chest physiotherapy is a manual airway clearance therapy that uses chest percussion (clapping, and vibration), and postural drainage. [1] [7] [8] However, they are labour-intensive, and time-consuming, and mechanical devices are often used instead. [5]

Mechanical

An intrapulmonary percussive ventilator machine CFIPVmachine.jpg
An intrapulmonary percussive ventilator machine

Mechanical devices used include positive expiratory pressure (PEP), intrapulmonary percussive ventilators, mechanical insufflation-exsufflation known as a mechanically assisted cough, [1] [9] and airway oscillatory devices. [10] Several mechanical techniques are used to dislodge mucus and encourage its expectoration. Chest percussion can be administered as a manual technique but can also be performed using specific devices that use chest wall oscillation or intrapulmonary percussive ventilation. Intrapulmonary percussive ventilators (IPVs) are machines which deliver short bursts of air through a mouthpiece to help to clear mucus. The air is delivered at a rate of approximately 150 pulses per minute and may be used with nebulized medication. Chest wall oscillation is a passive system that is not dependent on effort from the user. It involves the use of a special vest that employs the use of a compressor to inflate and deflate the vest rhythmically at timed intervals, and thus imposes high frequency chest wall oscillations that are transferred to the lungs. These oscillations thin airway mucus, and facilitate its removal by coughing. Delivery of air to the vest can be controlled manually.

Other methods such as biphasic cuirass ventilation, and associated clearance mode available in such devices, integrate a cough assistance phase, as well as a vibration phase for dislodging secretions. These are portable and adapted for home use. [11]

Positive expiratory pressure physiotherapy consists of providing a back pressure to the airways during expiration. This effect is provided by devices that consist of a mask or a mouthpiece in which a resistance is applied only on the expiration phase. [12] Operating principles of this technique seems to be the increase of gas pressure behind mucus through collateral ventilation along with a temporary increase in functional residual capacity preventing the early collapse of small airways during exhalation. [13] [14]

See also

Related Research Articles

<span class="mw-page-title-main">Cystic fibrosis</span> Genetic disorder inhibiting clearance of mucus from the lungs

Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably Staphylococcus aureus. CF is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. The hallmark feature of CF is the accumulation of thick mucus in different organs. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. Other signs and symptoms may include sinus infections, poor growth, fatty stool, clubbing of the fingers and toes, and infertility in most males. Different people may have different degrees of symptoms.

<span class="mw-page-title-main">Cough</span> Sudden expulsion of air from the lungs as a reflex to clear irritants

A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.

<span class="mw-page-title-main">Mechanical ventilation</span> Method to mechanically assist or replace spontaneous breathing

Mechanical ventilation or assisted ventilation is the medical term for using a ventilator machine to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit.

<span class="mw-page-title-main">Bronchiectasis</span> Disease of the lungs

Bronchiectasis is a disease in which there is permanent enlargement of parts of the airways of the lung. Symptoms typically include a chronic cough with mucus production. Other symptoms include shortness of breath, coughing up blood, and chest pain. Wheezing and nail clubbing may also occur. Those with the disease often get lung infections.

Crackles are the clicking, rattling, or crackling noises that may be made by one or both lungs of a human with a respiratory disease during inhalation, and occasionally during exhalation. They are usually heard only with a stethoscope. Pulmonary crackles are abnormal breath sounds that were formerly referred to as rales.

<span class="mw-page-title-main">Mucus</span> Secretion produced by mucous membranes

Mucus is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is a viscous colloid containing inorganic salts, antimicrobial enzymes, immunoglobulins, and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus serves to protect epithelial cells in the linings of the respiratory, digestive, and urogenital systems, and structures in the visual and auditory systems from pathogenic fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract.

<span class="mw-page-title-main">Atelectasis</span> Partial collapse of a lung causing reduced gas exchange

Atelectasis is the partial collapse or closure of a lung resulting in reduced or absent gas exchange. It is usually unilateral, affecting part or all of one lung. It is a condition where the alveoli are deflated down to little or no volume, as distinct from pulmonary consolidation, in which they are filled with liquid. It is often referred to informally as a collapsed lung, although more accurately it usually involves only a partial collapse, and that ambiguous term is also informally used for a fully collapsed lung caused by a pneumothorax.

Chest wall oscillation is when devices are used in airway clearance therapy to clear excess mucus from lung airways. It is principally used in the treatment of cystic fibrosis, but is gaining use in the treatment of other diseases, such as bronchiectasis, COPD, cerebral palsy and muscular dystrophy, in which excessive mucus can block airways due to excessive production or impaired clearance.

Acute severe asthma, also known as status asthmaticus, is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators (inhalers) and corticosteroids. Asthma is caused by multiple genes, some having protective effect, with each gene having its own tendency to be influenced by the environment although a genetic link leading to acute severe asthma is still unknown. Symptoms include chest tightness, rapidly progressive dyspnea, dry cough, use of accessory respiratory muscles, fast and/or labored breathing, and extreme wheezing. It is a life-threatening episode of airway obstruction and is considered a medical emergency. Complications include cardiac and/or respiratory arrest. The increasing prevalence of atopy and asthma remains unexplained but may be due to infection with respiratory viruses.

<span class="mw-page-title-main">Chest physiotherapy</span> Treatments to improve breathing by indirect removal of mucus from breathing passage

Chest physiotherapy (CPT) are treatments generally performed by physical therapists and respiratory therapists, whereby breathing is improved by the indirect removal of mucus from the breathing passages of a patient. Other terms include respiratory or cardio-thoracic physiotherapy.

Postural drainage (PD) is the drainage of lung secretions using gravity. It is used to treat a variety of conditions that cause the build-up of secretions in the lungs.

<span class="mw-page-title-main">Obstructive lung disease</span> Category of respiratory disease characterized by airway obstruction

Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. Many obstructive diseases of the lung result from narrowing (obstruction) of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, problems exhaling, and frequent medical clinic visits and hospitalizations. Types of obstructive lung disease include asthma, bronchiectasis, bronchitis and chronic obstructive pulmonary disease (COPD). Although COPD shares similar characteristics with all other obstructive lung diseases, such as the signs of coughing and wheezing, they are distinct conditions in terms of disease onset, frequency of symptoms, and reversibility of airway obstruction. Cystic fibrosis is also sometimes included in obstructive pulmonary disease.

<span class="mw-page-title-main">Pulmonary function testing</span> Test to evaluate respiratory system

Pulmonary function testing (PFT) is a complete evaluation of the respiratory system including patient history, physical examinations, and tests of pulmonary function. The primary purpose of pulmonary function testing is to identify the severity of pulmonary impairment. Pulmonary function testing has diagnostic and therapeutic roles and helps clinicians answer some general questions about patients with lung disease. PFTs are normally performed by a pulmonary function technologist, respiratory therapist, respiratory physiologist, physiotherapist, pulmonologist, or general practitioner.

<span class="mw-page-title-main">Mucociliary clearance</span>

Mucociliary clearance (MCC), mucociliary transport, or the mucociliary escalator describes the self-clearing mechanism of the airways in the respiratory system. It is one of the two protective processes for the lungs in removing inhaled particles including pathogens before they can reach the delicate tissue of the lungs. The other clearance mechanism is provided by the cough reflex. Mucociliary clearance has a major role in pulmonary hygiene.

Pulmonary hygiene, also referred to as pulmonary toilet, is a set of methods used to clear mucus and secretions from the airways. The word pulmonary refers to the lungs. The word toilet, related to the French toilette, refers to body care and hygiene; this root is used in words such as toiletry that also relate to cleansing.

<span class="mw-page-title-main">Chronic obstructive pulmonary disease</span> Lung disease involving long-term poor airflow

Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. GOLD 2024 defined COPD as a heterogeneous lung condition characterized by chronic respiratory symptoms due to abnormalities of the airways and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction.

<span class="mw-page-title-main">Denufosol</span> Chemical compound

Denufosol (INN) is an inhaled drug for the treatment of cystic fibrosis, being developed by Inspire Pharmaceuticals and sponsored by the Cystic Fibrosis Foundation. It was tested in two Phase III clinical trials, TIGER-1 and TIGER-2. Initially, in the first Phase III trial, TIGER-1, the compound showed significant results as compared with placebo. In the second Phase III trial, TIGER-2, the compound did not meet the primary endpoint, a significant change in baseline FEV1 at the week 48 endpoint as compared to placebo. As of 2011, no additional clinical studies are being conducted with the compound.

Physiotherapists treating patients following uncomplicated coronary artery bypass surgery surgery continue to use interventions such as deep breathing exercises that are not supported by best available evidence. Standardised guidelines may be required to better match clinical practice with current literature.

A respiratory pressure meter measures the maximum inspiratory and expiratory pressures that a patient can generate at either the mouth (MIP and MEP) or inspiratory pressure a patient can generate through their nose via a sniff maneuver (SNIP). These measurements require patient cooperation and are known as volitional tests of respiratory muscle strength. Handheld devices displaying the measurement achieved in centimetres of water pressure (cmH2O) and the pressure trace created, allow quick patient testing away from the traditional pulmonary laboratory and are useful for ward-based, out-patient and preoperative assessment, as well as for use by pulmonologists and physiotherapists.

<span class="mw-page-title-main">Cystic fibrosis and race</span>

Underrepresented populations, especially black and hispanic populations with cystic fibrosis are often not successfully diagnosed. This is in part due to the minimal dissemination of existing data on patients from these underrepresented groups. While white populations do appear to experience a higher frequency of cystic fibrosis, other ethnicities are also affected and not always by the same biological mechanisms. Thus, many healthcare and treatment options are less reliable or unavailable to underrepresented populations. This issue affects the level at which public health needs are being met across the world.

References

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