Overview of the disease
A common occupational lung disease characterized by diffuse fibrosis of the lung tissue, with no symptoms in the early stages, and symptoms such as cough, sputum, chest pain, chest tightness, shortness of breath, etc. occurring with the progression of the disease. The cause of the disease is the prolonged inhalation of silica-containing dusts. Treatment mainly includes general treatment, medication, surgical treatment, and lung lavage.
Definition
Silicosis, also known as silicosis, is a disease characterized by diffuse fibrosis of the lung tissue due to long-term inhalation of dust with a high content of free silica.
Types
Silicosis can be categorized into three types according to the progression of the disease. Usually, the higher the concentration of silica dust exposure, the shorter the incubation period and the more severe the disease.
Rapid-onset silicosis: Exposure to extremely high concentrations of free silica dust results in the onset of the disease within a very short period of time, even within 1 year.
Radical silicosis: exposure to higher concentrations of free silica dust, generally 5 to 10 years after exposure to dust onset.
Ordinary type silicosis: exposure to a certain concentration of free silica dust, generally develops more than 20 years after exposure to the dust.
Morbidity
The prevalence of silicosis is difficult to estimate because patients tend to develop the disease 10 to 15 years after exposure to silica dust, and the lung lesions continue to develop even when they are no longer exposed to silica dust.
According to statistics, as of 2017, more than 850,000 cases of occupational pneumoconiosis, mainly silicosis and coal workers’ pneumoconiosis, have accumulated nationwide.
It is mostly found in occupational groups that have been exposed to free silica-containing dust for a long period of time, such as workers who have been engaged in long-term mining, quarrying, pit operations, and production operations in quartz powder factories, glass factories, refractory factories, and ceramic factories.
Causes
Causes
The main cause of the disease is long-term inhalation of dust containing free silica.
The occurrence and severity of silicosis are related to a variety of factors, such as the free silica content of the dust, the concentration of dust in the air, the size of the dust particles, the duration of exposure, protective measures, and one’s own defense function.
In general, silica dust particles <5 microns can be inhaled into the lungs and reach the alveoli (the smallest unit of the lungs), and are aggregated locally to form silica nodules. The smaller the silica dust particles, the stronger the pathogenicity, of which 1 to 2 micron silica dust particles are the most pathogenic.
Predisposing factors
Engaging in rock drilling and blasting when engaged in mining, quarrying and digging tunnels.
Engaged in operations such as rolling stones, crushing, manufacturing glass, enamel and refractory materials.
Engaged in sand milling, sand mixing, molding, furnace laying, sand blasting and sand cleaning in the foundry industry.
Poor awareness of dust prevention.
Failure to wear dust masks or helmets when working under silica dust exposure.
Smoking.
Chronic lesions of the respiratory system, such as chronic rhinitis, chronic bronchitis, emphysema and tuberculosis.
Symptoms
Main Symptoms
Symptoms may be asymptomatic or insignificant in the early stages. With the development of lesions, the symptoms gradually worsen, mainly the following manifestations.
Cough and sputum
The degree of cough and the amount of sputum are closely related to bronchitis or secondary infection in the lungs, and are often inconsistent with the degree of silicosis.
A few patients may have blood in sputum.
Chest pain
Chest pain is often pinprick-like.
It occurs on one or both sides of the anterior chest.
It is not related to respiration, body position and labor.
Often occurs on rainy days and when the climate changes.
Chest tightness and shortness of breath
If the lesion is extensive and progresses rapidly, the symptoms of chest tightness and shortness of breath (labored breathing or insufficient breath) are obvious and gradually worsen.
It may be accompanied by dizziness, generalized weakness, palpitation, emaciation, and susceptibility to infection.
Complications
Tuberculosis
The more severe the silicosis, the higher the probability of infection with Mycobacterium tuberculosis and the higher the probability of complication with tuberculosis.
Symptoms such as night sweating, prolonged low-grade fever, generalized weakness, fear of cold, cough, hemoptysis and chest pain may occur.
Chronic Obstructive Pulmonary Disease
Initially, there is shortness of breath only when laboring, going up stairs or climbing slopes, which can be relieved after resting.
With the development of the lesion, shortness of breath can also occur during activities on level ground.
In the early stage, there will be varying degrees of hypoxemia, with labored breathing, chest tightness, and bruising of the lips and nail beds.
In severe cases, symptoms of respiratory failure may occur, such as cyanosis (cyanosis of the skin and mucous membranes, most often seen on the lips and tip of the nose), headache, drowsiness, and trance.
Spontaneous pneumothorax
Can occur after a hard breath-hold or a sharp cough.
It is characterized by sudden extreme dyspnea, sitting breathing (keeping sitting or semi-recumbent position, not lying down).
Severe hypoxia may result in cyanosis, agitation, coma, or even asphyxia.
Pulmonary heart disease (cor pulmonale)
Severe dyspnea, increased respiratory rate, sedentary breathing, oliguria, and bilateral lower extremity or generalized edema may be present.
Consultation
Department of Medicine
Respiratory Medicine
Coughing, coughing up sputum, chest pain, chest tightness, shortness of breath and other symptoms, it is recommended to consult a doctor promptly.
Emergency Medicine
For emergencies such as rapidly worsening respiratory distress, cyanosis, hemoptysis, or unconsciousness, it is recommended that you consult the Emergency Department immediately.
Preparation for medical treatment
Consultation: Registration, Preparation of documents, Frequently asked questions
Tips for seeking medical treatment
Chest X-rays or chest CT are often needed, so avoid wearing clothing made of metal, and those who are pregnant or planning to become pregnant should inform the doctor in time.
Preparation Checklist
Symptom list
Pay particular attention to the time of onset of symptoms and special symptoms.
Is there a cough? How long has the cough lasted?
Is there sputum? What kind of phlegm?
Is there chest pain or tightness?
How long have the symptoms been present?
Under what circumstances do the symptoms worsen or lessen?
List of medical history
What kind of work was performed? Any prolonged exposure to mineral dust?
Checklist
Test results of the last six months, which can be carried to the doctor’s office
Laboratory tests: blood test, C-reactive protein, arterial blood gas analysis, sputum examination
Imaging: Chest X-ray, Chest CT
Others: Lung function test
Medication List
Medication used in the last 3 months, if there is a box or package, you can bring it to the doctor.
Antibiotics: Levofloxacin, Cefaclor, Penicillin, Azithromycin
Bronchodilators: salbutamol, terbutaline, aminophylline, ipratropium bromide
Cough suppressants: codeine, dextromethorphan
Diagnosis
Diagnosis is based on
Medical history
History of exposure to productive free silica dust, such as having worked in mining, quarrying, or pit operations, or having worked in quartz powder factories, glass factories, refractory factories, or ceramic factories.
There is a history of chronic respiratory disease.
Clinical manifestations
Symptoms such as cough, sputum, chest pain, chest tightness, shortness of breath, etc., which are gradually aggravated and recurring, may occur.
However, these symptoms are not specific and can occur in other lung diseases, so they are of little significance in confirming the diagnosis.
Laboratory tests
Laboratory tests can help determine the nature and extent of the lung disease and are often used to rule out other diseases and to see if there are any comorbidities or complications.
Blood tests
Routine blood tests: white blood cells and neutrophils may be elevated in cases of exacerbation, such as co-infections, and fasting is not required before testing.
Arterial blood gas analysis: to understand whether the patient has hypoxia and the degree of hypoxia, to determine whether there is respiratory failure, acid-base balance disorders and other conditions.
Erythrocyte Sedimentation Rate (ESR): it is often increased when combined with specific and non-specific infections.
C-reactive protein (CRP): often elevated when there is inflammation.
Sputum pathogenetic examination
Helps to confirm the diagnosis of respiratory and lung infections, as well as to clarify the nature of the infection (bacterial, viral, mycoplasma, etc.).
The mouth should be kept clean before the examination.
Imaging
Chest X-ray
It is the main diagnostic basis for silicosis.
X-ray findings are related to the severity of the lesion and mainly show round nodular shadows of silicosis, although the size and shape of the shadows vary from patient to patient.
The disadvantage is that it is difficult to detect nodules with a small diameter.
Avoid wearing metal jewelry or clothing with metal button fittings during the examination.
Chest CT
Compared with chest X-ray, chest CT is more sensitive and has an advantage in detecting small round shadows <1.5 mm in diameter.
It is more likely to detect large shadows located behind the heart and mediastinum, in the spine or paramedian mediastinum, as well as small fused shadows at the tip of the lungs or behind the clavicle.
It is superior in the detection of emphysema, pulmonary blisters, pleural plaques, and in the detection of cavities and calcifications within large shadows.
Specialized Tests
Lung function test
It is mainly used to understand the respiratory function and clarify whether there is any pulmonary dysfunction and its degree and type.
In early stage patients, the impairment of lung function is not obvious.
With the progress of the disease, there may be restrictive ventilation dysfunction.
When combined with bronchial disease, there may be obstructive ventilation dysfunction or mixed ventilation dysfunction.
During the examination, relax and follow the doctor’s instructions for exhalation and inhalation.
Transbronchoscopic lung biopsy
Dusty lesions such as pneumoconiosis nodules, dusty diffuse pulmonary fibrosis, and dusty plaques were observed in the lung tissue specimens, and the lesions were visible as quartz dust particles by polarized light microscopy, which is an adjunctive support for interpreting the imaging changes.
The absence of dusty lesions in the lung tissue is also not a basis for ruling out pneumoconiosis.
It helps to identify fusion lesions of silicosis close to the hilum and central lung cancer.
Bronchoscopy usually requires insertion through the nose, and care should be taken to cooperate with the examiner during the examination and to inform the healthcare provider of any unusual symptoms after the examination.
Differential Diagnosis
Other occupational pneumoconiosis
Similarities: Both have symptoms such as coughing, sputum, chest pain, chest tightness and dyspnea.
Differences: There are differences in the pathogenic production dust inhaled, e.g. coal workers’ pneumoconiosis is caused by long-term inhalation of coal dust, asbestosis is caused by long-term inhalation of asbestos dust. Generally, it can be differentiated by the history of exposure to productive mineral dusts and imaging features.
Acute Cornual Tuberculosis
Similarities: Both have different degrees of cough, sputum, chills, night sweating and other symptoms.
Differences: 2-3 weeks after the onset of acute cornual tuberculosis, chest X-ray can find consistent size and uniform distribution of cornual shadows, densely spread on both sides of the lung field. Combined with the history of exposure to Mycobacterium tuberculosis, clinical manifestations and a positive tuberculin test, as well as dynamic observation of imaging, the differential diagnosis can be clarified.
Pulmonary ferritinosis
Similarity: both have symptoms such as cough, sputum and hemoptysis.
Differences: Pulmonary ferritinosis shows spot shadows on chest X-ray, which persist for a long time without change; there is no history of exposure to productive mineral dust; sputum smear examination can clearly differentiate the disease.
Nodular disease
Similarities: both have symptoms such as cough, sputum, chest pain, chest tightness and dyspnea.
Differences: nodular disease is typically characterized by non-caseating necrotizing epithelioid granuloma with negative antacid stain; no history of exposure to productive mineral dust.
Lung cancer
Similarities: both have symptoms such as cough, sputum, chest pain, chest tightness and dyspnea.
Differences: lung cancer is often accompanied by hilar lymph node metastasis, resulting in enlarged hilar lymph nodes on the same side of the lung. x-ray chest radiography, PET-CT, bronchoscopy, transcavitary needle aspiration cytology or histology, and sputum cytology are helpful for differential diagnosis.
Treatment
Treatment purpose and principle
Treatment purpose: to alleviate patients’ pain, slow down the progress of the disease, improve the quality of life and social participation, and prolong life.
Treatment principle: In order to eliminate or reduce the harm of various comorbidities, comprehensive clinical treatment is needed, including general symptomatic supportive therapy and drug therapy.
Treatment Methods
General treatment
Reasonable oxygen therapy
Mainly used to relieve respiratory distress.
Nasal catheter oxygenation is suitable for mild to moderate hypoxemia.
Mask oxygenation is generally used for patients who need higher oxygen concentration.
Do not adjust the oxygen flow rate or stop oxygen therapy.
Nutritional support
Patients are in a high metabolic state and need to ensure adequate nutrition.
For critically ill patients who cannot eat by mouth, a nasogastric tube or nasojejunal tube can be placed.
Specific nutritional programs should be developed by professionals according to individual conditions.
Rest
Avoid exertion, take proper rest, and closely monitor respiration, heart rate, and blood pressure in order to understand the condition.
For those who have been bedridden for a long time, they should turn over and pat the back regularly to keep the airway open.
Medication
Asthma treatment
β2 agonists
Helps to relax airway smooth muscle.
Short-acting β2 agonists can choose salbutamol, terbutaline, etc., and long-acting β2 agonists can choose salmeterol, formoterol, etc..
Adverse effects are rare, mainly muscle tremor and sinus tachycardia.
Theophyllines
Relatively weak bronchodilatory effect, at the same time have anti-inflammatory and immunomodulatory effects.
Aminophylline, dihydroxypropyl theophylline, and doxophylline are available.
Aminophylline is easy to cause gastrointestinal reaction after oral intake, it is advisable to take it after meal or choose enteric-coated tablets.
Anticholinergic drugs
Anticholinergic drugs have the effect of relaxing bronchial smooth muscle and inhibiting glandular secretion.
Short-acting anticholinergic drugs can choose ipratropium bromide, long-acting anticholinergic drugs can choose tiotropium bromide.
Adverse effects are rare and may include dry mouth, pharyngeal irritation, nausea and cough.
Use with caution in patients with glaucoma and prostatic hypertrophy.
Expectorant treatment
There are many kinds of expectorant drugs, among which mucolytic agents are widely used in clinic because of their good expectorant effect, such as proteolytic enzyme preparations, polysaccharide fiber decomposition agents, disulfide bond cleavage agents.
Proteolytic enzyme preparations, such as Serrapeptase.
Polysaccharide fiber decomposer, such as bromhexine, ambroxol.
Disulfide bond cleavage agents, e.g. N-acetylcysteine, carbocysteine.
Cough suppressants
Central cough suppressants
They work by directly inhibiting the medullary cough center, and should be used with caution in patients with pneumoconiosis as they are not conducive to coughing up sputum.
Commonly used codeine, dextromethorphan and so on.
Codeine cough suppressant effect is strong, so it is not conducive to phlegm expulsion, and addictive and dependent. It can be used for dry and irritating cough, especially with chest pain.
Dextromethorphan has no addictive and analgesic effects. It is suitable for cough with little or no sputum, and should not be used for those with much sputum.
Peripheral cough suppressants
Acts by inhibiting cough reflex receptors as well as effectors.
Nyquiline is optional, non-dependent and suitable for coughs of different causes.
Anti-infective treatment
Under the condition of smooth drainage of respiratory secretions, effective anti-infective drugs should be selected with reference to the results of sputum bacterial culture and drug sensitivity test.
Quinolones (e.g. levofloxacin) or β-lactams (e.g. cephalosporins, penicillins) combined with macrolides (e.g. erythromycin, azithromycin) can be used for drug treatment.
Special reminder
During the drug treatment, you should insist on following the doctor’s instructions strictly, not change the drug dose without authorization or stop the drug suddenly, to ensure that the treatment plan is implemented.
There is no specific treatment for this disease, do not believe in folk “bias prescription” “secret prescription”.
Surgery
Lung transplantation is the only cure for silicosis.
Silicosis is a chronic disease and generally has little impact on life expectancy in the absence of serious complications. Therefore, lung transplantation is not usually recommended as a treatment option for pneumoconiosis.
In the few cases where the disease is severe, it is recommended to consult a physician to see if you meet the surgical indications for lung transplantation.
After lung transplantation, not only rejection reaction but also complications such as infection and renal insufficiency may occur, which will seriously affect the quality of life and survival of patients.
Whole lung lavage therapy
It is generally not used as a routine treatment for silicosis.
Whole lung lavage can wash out the sputum and secretions accumulated in the respiratory tract, which can improve the clinical symptoms in the short term, but it has no obvious effect on improving the lung function and slowing down the progression of the disease.
Total lung lavage may only be considered on balance for patients with large amounts of sputum that cannot be easily coughed up and is blocking the airways.
Prognosis
Cure
Silicosis usually has a long duration and requires lifelong rehabilitation.
With prompt removal from the dust environment and active treatment, most cases can be treated to reduce symptoms, delay the disease and improve quality of life.
Hazards
The disease is a chronic disease with a long duration, which can affect normal work and life.
It is prone to respiratory dysfunction, pulmonary heart disease, pneumothorax, tuberculosis and other complications, which directly affects the progress and prognosis of the disease, and further affects physical health and quality of life.
Severe cases may lose their ability to work and may even be life-threatening.
Daily
Daily Management
Dietary management
Patients with severe disease, combined with tuberculosis or recurrent lung infections with silicosis are often malnourished and should be supplemented with adequate nutrition.
Closely monitor the overall body condition and various indicators in order to formulate a specific nutritional supply program.
For those who can eat normally by mouth, it is advisable to increase the intake of high quality and high protein (e.g. eggs, milk, lean meat, etc.), and to maintain food diversity and balanced nutrition.
If there is no cardiac or renal insufficiency, more water can be consumed in moderation to replenish the consumed water and dilute the sputum, which is conducive to sputum discharge.
Health management
Once diagnosed, patients with silicosis should be immediately removed from the original dust operation position and should not be re-engaged in other dust-exposed work.
Work and rest management
Combine work and rest, pay attention to rest, avoid staying up late.
The more serious patients must rest in bed to reduce physical exertion, reduce oxygen consumption, and minimize self-care activities and unnecessary operations.
When respiratory effort can try to take a semi-recumbent position or sitting position, lying down on the bed table, in order to improve the respiratory situation.
Those who are bedridden for a long time should have regular lower limb massage to prevent lower limb deep vein thrombosis.
Exercise management
Perform respiratory control training, respiratory muscle training, thoracic relaxation training, strength endurance training and aerobic exercise according to the regularity of the doctor’s instruction in order to improve respiratory efficiency and restore lung function.
Progress gradually and avoid activities with high oxygen consumption.
Keep the airway open
Family members can help the patient to carry out back percussion and sputum expulsion, in order to promote the expulsion of sputum.
The sputum expectoration operation should be scheduled to be completed from 2 hours after meal to 30 minutes before meal in order to avoid triggering vomiting.
The percussionist bends the fingers of both hands together so that the side of the palm is in the shape of a cup, and percusses the chest wall from the bottom of the lungs from the bottom up, from the outside in, rapidly and rhythmically with the force of the wrist.
Each lung lobe percussion 1 ~ 3 minutes, percussion when a hollow and deep beat sound is indicated that the percussion technique is correct.
The force of percussion should be moderate, so that the patient does not feel pain.
When percussion should pay close attention to the patient’s response.
Under the guidance of the doctor to learn effective breathing and coughing, coughing techniques, such as lip-contraction breathing, abdominal breathing and other methods to delay the deterioration of lung function.
Contact your doctor if you notice any special smell or changes in sputum volume, color and viscosity.
Avoid cold stimuli
Observe the weather changes and increase clothing appropriately in cold weather.
Wear warm hats, masks, gloves and warm socks when going out.
Preventing Infections
Avoid going to places where people gather.
Get vaccinated against influenza and pneumonia in winter and spring.
Quit smoking
Smoking not only increases the risk of respiratory infections, but also accelerates pulmonary fibrosis, so it is important for patients with silicosis to quit smoking and avoid second-hand smoke.
Psychological support
Because of the long duration of silicosis, it is common to feel nervous and anxious. Patients should face the disease with a positive and optimistic attitude and build up confidence in overcoming the disease.
Family members should give more psychological care to the patients and encourage them to tell the factors that cause or aggravate anxiety.
Disease Detection
Normally, attention should be paid to monitoring the respiratory rate, blood pressure, heart rate, sputum volume and character.
If symptoms worsen, or new symptoms appear, consult the doctor promptly.
Follow the doctor’s prescribed schedule for follow-up appointments.
Prevention
Frequent occupational hygiene monitoring should be carried out in dusty workplaces to control the air concentration of dust in the workplace within the occupational exposure limits.
Reasonable dietary arrangements should be made to strengthen nutrition and improve physical fitness.
Workers working with dust should use protective equipment and wear dust masks and helmets to prevent dust from entering the human respiratory tract.
Have regular medical checkups and actively treat lung diseases.
Go to crowded places as little as possible to avoid contact with people with respiratory tract infections and reduce the chance of infection.
Wear a mask when going out and wash your hands frequently.
Avoid stimulation by adverse factors such as exertion and emotional excitement.
Strengthen sports and exercise, which is conducive to improving immunity and strengthening body resistance.