If you have phlegm but can't cough it up, airway clearance technology can help you

Coughing and coughing up phlegm!

This should be familiar to everyone. In clinical practice, we often encounter patients who have difficulty expectorating. If the sputum cannot be discharged, it may endanger the patient's life at any time. In many cases, we will choose to suction the patient's sputum. So in addition to suctioning, what other methods can we use to help patients expectorate and clear airway secretions?

Today we will introduce the expectoration technique - airway clearance technique (ACT).

Airway Clearance Therapy ( ACT )

Use physical or mechanical means to act on the airflow to help the sputum in the trachea and bronchi to be discharged or induce coughing to discharge sputum. Currently, the commonly used airway clearance techniques mainly include percussion, postural drainage, forced exhalation technique, high-frequency chest wall compression (HFCWC), oscillatory positive expiratory pressure (OPEP), etc. Due to the different mechanisms of clearing secretions by different airway clearance techniques, they are suitable for different populations.

Why do we need airway clearance?

Respiratory diseases can cause damage to cilia function, affecting the production of airway secretions, mucus rheology, and cough reflex. Secretions accumulate and stagnate in the airways, providing opportunities for bacterial colonization and infection, stimulating the occurrence of inflammatory responses, and creating conditions for airway damage. Therefore, effective removal of secretions is particularly important to reduce the occurrence of pneumonia and other related complications.

Indications for airway clearance

1. Patients who produce large amounts of sputum (>30 ml/day): Chronic diseases that are prone to produce large amounts of sputum, such as bronchiectasis, ciliary dyskinesia syndrome, chronic bronchitis, cystic fibrosis, etc.

2. Prevent patients from having sputum retention: for example, patients who are bedridden for a long time, patients who have undergone chest and abdominal surgery, patients with chronic obstructive pulmonary disease, and patients whose coughing ability is weakened due to neuromuscular diseases.

Conditions for airway clearance technique

1. Clear airway

2. A fully functional mucociliary system;

3. Effective cough;

Coughing is one of the most important protective reflexes of the respiratory system. It can clear excess mucus and foreign matter in larger airways, help normal mucociliary transport and clearance, and ensure airway patency.

A cough consists of four main stages: stimulation, inspiration, breath retention, and expulsion.

How to perform airway clearance

01 Smack

① Bend your palm slightly into a bow shape, put your five fingers together, make your hand into a cup shape, use your wrist as a fulcrum, and use the strength of your upper arm to rhythmically tap the patient's chest wall.

② The amplitude of tapping should be about 10cm, the frequency of tapping should be 3 to 5 times per second, and tapping should be done with one or both hands alternately. It is recommended to tap through thinner clothing to improve the patient's comfort.

③ Focus on tapping the area that needs drainage, move back and forth in a circular manner in the local area, and then tap from the periphery to the center along the direction of the bronchus.

④ During the operation, care should be taken to avoid traumatic or surgical sites, and do not directly tap protruding parts such as the clavicle, vertebrae or sternum. The direction should always be parallel to the ribs.

02 Directed cough (DC)

① For patients who are conscious and can cooperate with coughing, guided coughing can be used to improve the efficiency of coughing.

②The patient sits down, leans forward slightly, relaxes his shoulders, and takes 5 to 6 deep breaths.

③ Ask the patient to take a slow, deep breath and hold his breath for 1 second, open his mouth and cough several times continuously while contracting the abdominal muscles.

④ If the patient has a weak cough or has wound pain after thoracic or abdominal surgery, the operator can place the palms of both hands on the patient's lower chest or upper abdomen to apply pressure when the patient coughs, or place a pillow on the legs to press against the abdomen to apply pressure.

⑤After you stop coughing, purse your lips and slowly exhale the remaining air. Take a slow, deep breath again and repeat the above steps.

03 Improve lung ventilation

(1) Hold your breath for 3 seconds

Take a deep breath and hold your breath for 3 seconds. Normal lung tissue is inflated first, and the alveolar traction promotes the expansion of obstructed lung tissue. Gas is transferred from normal lung tissue to obstructed lung tissue through bypass ventilation.

(2) Postural drainage

The gravity effect of the patient in different body positions is used to move secretions from the peripheral airways to the large airways.

① Before treatment, the location of the lesion and the patient's condition should be determined based on physical examination and imaging, and the drainage position should be determined.

② Before the operation, the purpose and method of postural drainage should be fully explained to the conscious patient to obtain his cooperation.

③ For patients with artificial airway, attention should be paid to fixing the tube to prevent accidental dislodgment or displacement. Appropriate sedatives may be given when necessary.

④ When choosing the body position, the lesion should be located at a high position, with the opening of the drainage bronchus facing downward.

⑤ The patient's condition needs to be closely monitored during treatment: subjective feelings, hemodynamics, oxygenation, etc.

⑥ It is recommended to do this 3 to 4 times a day, and maintain each position for 20 to 30 minutes. For patients with more sputum and tolerance, the drainage time and frequency can be appropriately increased. The effect will be better if combined with correct tapping.

04 Use expiratory airflow to promote secretion clearance

Coughing in normal people can effectively clear large airway secretions, but coughing in patients with respiratory diseases may cause premature closure of narrow airways. Repeated coughing causes repeated pressure on the airways, reducing the expiratory flow rate and limiting the effectiveness of coughing. Airway clearing technology can increase the expiratory flow rate and generate airway wall shear force, thereby promoting the headward movement of secretions.

Forced exhalation technique: ask the patient to exert appropriate force and prolong the exhalation time, making a "huff~" sound. For example, ask the patient to blow into the palms of their hands to warm them up; blow into a mirror to make the mirror fog up; or put a tissue in front of them and blow into it to make it float, etc.

Compared with coughing, the advantage of forced exhalation technique is that it can exhale at different lung volumes, change the isobaric point, and facilitate the drainage of peripheral sputum.

05 Oscillating positive end-expiratory pressure

①Positive end-expiratory pressure

Connect to the positive end-expiratory pressure device through a mask, mouthpiece, T-tube, one-way valve, etc. After normal inhalation, exhale according to the inhalation-exhalation ratio of 1:3 to 1:4, 10 to 20 breaths per group, and practice active exhalation techniques and guided coughing after completion.

② Oscillating positive end-expiratory pressure

Combining the principles of oscillating expectoration and expiratory positive pressure expectoration, it can better promote the discharge of sputum. When using the OPEP device, the patient needs to resist a fixed resistance when exhaling, just like doing pursed lip breathing, to generate a relatively high positive end-expiratory pressure, causing airflow vibration, so that a certain expiratory positive pressure is formed in the patient's airway, thereby maintaining the airway open throughout the exhalation phase, promoting the loosening of secretions in the airway, and expelling them into the central large airway. Finally, combined with an effective cough, sputum can be discharged from the lungs to the body.

③Easy cough device

When exhaling, the stainless steel moves up and down, intermittently blocking the airflow to produce airflow oscillation and positive end-expiratory pressure. Method: ① Breathing (repeat 6-10 times: inhale slowly, hold your breath for 3 seconds at the end of inhalation, and exhale towards the instrument with slight force). ② Exhale forcefully: exhale + calm breathing 1-3 times. Do 6-10 cycles for each treatment.

Acapella device: uses a counterbalanced plug and magnets to create airflow oscillations. Suitable for any position, usually sitting. Inhalation and exhalation are performed through a closed device.

06 High-frequency chest wall oscillation

① It consists of two parts, namely a variable gas-vibration generator and a non-stretchable inflatable vest or vest that can cover the entire torso of the patient. The two are connected by a pipeline. The gas-vibration generator fills and extracts a small volume of air into the vest at a high rate, slightly compressing and releasing the patient's chest wall, causing sputum in the airway to fall off and accumulate. At the same time, the airflow pulse can also cause a similar "mild cough" action.

② During treatment, the patient sits or semi-sit-and-lie, and the oscillation frequency is set according to the patient's tolerance and treatment response. The initial setting is 5-25 Hz, and it is gradually increased from small to large during treatment. Depending on the patient's condition, it can be applied 1-6 times/d, 30 minutes/time.

③After use, the patient should be instructed to cough or expel secretions through artificial airway suction.

Conclusion

There are many intervention methods for airway clearance. In clinical practice, an individualized airway clearance plan can be formulated based on the patient's age, disease severity, degree of understanding and cooperation, and the mastery of specific techniques.

An appropriate airway clearance program can promote effective coughing and sputum expectoration in patients, reduce airflow limitation and lung infection caused by mucus accumulation and blockage, improve patients' clinical symptoms, and increase their activity endurance, thereby improving their quality of life.

Author: Yan Ni, head nurse, Xiaogan Central Hospital

Reviewer: Xiao Yanping, head therapist of the Department of Rehabilitation Medicine, the First Affiliated Hospital of Gannan Medical College, member of the Rehabilitation Therapy Professional Committee of the Jiangxi Rehabilitation Medicine Association

Pan Huoying, head nurse of the Department of Neurology, the First Affiliated Hospital of Gannan Medical College, member of the Science Popularization Working Committee of the Chinese Rehabilitation Medicine Association

Editor: Liang Juping, Illustration: Li Chuan (Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine)