LECTURE
Theme of lecture: Pneumoconiosis. Silicosis. Silicatosis. Vibration disease
Many production processes in various industries associated with generation of
dust.These
are
mining
and
coal
industry metallurgical and
engineering enterprises; productionof building materials; electric welding works; text
ile companies; processing of agricultural products - cotton, corn, flaxetc.
Occupational lung diseases can be classified according to several schemes.
1.
Clinical presentation
2.
Type of exposure to agent

Organic dusts

Inorganic dusts

Metals

Biological factors
3.
Types of industry potentially associated with respiratory diseases
The new classification by the Russian Academy of Medical Sciences
Research institute of Health Medicine, 1996 year. The new classification is
allocated three main groups of pneumoconiosis:
1. Pneumoconiosis, which develops by influence moderately and
highly fibrogenic dust (with containing free silica more than 10 %) –
silicosis, antracosilicosis,silicosiderhosis, silicisilicatosis. These pneumoconiosis are
wide spread among sandblasters, fettlers, miners, workers for the production of
ceramic materials. They are inclined to progressive fibrotic process and complication
of tuberculosis infection.
2. Pneumoconiosis, which develops by influence mild fibrogenic dust (with
containing free silica less than 10 % or not containing it) –
silicatosis (asbestosis, talcosis,caolinosis, olivinosis, nephelinosis, pneumoconiosis
from exposure to cement dust) –carboconiosis (anthracosis, graphitosis, black-lung
carbon disease etc.), polisher’s and emery’s pneumoconiosis, metalloconiosis or
pneumoconiosis from exposure radiopaque dusts (siderosis, including of aerosol
electric welding or gas cutting iron products,baritoz, stanioz, manganokoniozetc).
They are characterized by moderate fibrosis, benign and slow-progressive duration,
often complicated by the non-specific infection, chronic bronchitis, which is mainly
determined by the severity of illness.
3. Pneumoconiosis, which develops by influence toxic-allergic aerosols (dust,
which containing metals-allergens, plastic and other polymeric material compounds,
organic dust etc) – berylliosis, aluminosis, farmer's lung and other hypersensitivity
pneumonitis. In the initial stages of the disease they are characterized by a clinical
picture of chronic bronchiolitis, alveolitis progressive course with the outcome of
fibrosis. Dust concentration is not critical in the development of this group of
pneumoconiosis. The disease is associated with a slight, but prolonged and close
contact with the allergen.
The International Labour Organization (ILO) in 2000, revised the
previous version of the classification of pneumoconiosis and amounted new, based
on the coding of radiographic evidence of disease. he purpose of creation
International Classification of X-ray is the standardization of methods of diagnosis of
pneumoconiosis.
International Labour organization, Geneva.List of occupational Diseases
(2002). ICD 10 classification:
1. Diseases caused by agents
1.1 Chemical agents ( 32 items)
1.2 Physical agents ( 8 items )
1.3 Biological agents ( infectious and parasitic diseases contracted in an
occupation where there is a par contracted in an occupation where there is a particular
risk of contamination )
2. Diseases by target organ systems
2.1 Occupational respiratory diseases
2.2 Occupational skin diseases
2.3 Occupational musculoskeletal disorders
3. Occupational cancer ( 15 items )
(Asbestos, Benzidineand compounds, Bischloromethylether, chromium and
compounds, coal tar, beta-naphthylamine, Vinylchloride, Benzene, Toxic nitro and
amino derivatives of benzene, Ionizing radiations, Tar, pitch bitumen, mineral oil,
and related compounds, coke oven emission, coke oven emission, wood dust ).
4. Other diseases
4.1 Miner’snystagmus
2.1 Occupational respiratory diseases
2.1.1 Pneumoconioses caused by sclerogenic mineral dusts
2.1.2 Bronchopulmonary disease caused by hard-metal dust
2.1.3 Bronchopulmonary disease caused by cotton, flax, hemp or sisal dust
2.1.4 Occupational asthma
2.1.5 Extrinsic allergic alveolitis
2.1.5 Siderosis
2.1.6 Chronic obstructive pulmonary diseases
2.1.7 Diseases caused by aluminium
2.1.9 Upper airways disorders
2.1.10 Any other respiratory disease not mentioned in the proceeding items
caused by an agent where the casual relationship is established
Basic principles of occupational lung diseases
Certain principles apply broadly to the full range of occupational respiratory
disorders

While a few environmental and occupational lung diseases may present
with pathognomonic features, most are difficult to distinguish from disorders
ofnonenvironmental origin

A given substance in the workplace or environment can cause more than
one clinical or pathologic entity

The etiology of many lung diseases may be multifactorial and
occupational factors may interact with other factors

The dose of exposure is an important determinant of the proportion of
people affected or the severity of disease

Individual differences in susceptibility to exposures do exist

The effects of a given occupational or environmental lung exposure
occur after the exposure with a predictable latency interval
The effects of an inhaled agent depend on many factors

its physical and chemical properties

the susceptibility of the exposed person

the site of deposition within the bronchial tree
Physical properties
•
physical state (solid particulates, mist, vapor and gases)
•
solubility
•
size, shape and density
•
concentration
•
penetrability
•
radioactivity
Chemical properties
•
alkalinity and acidity
•
fibrogenicity
•
antigenicity
Susceptibility of exposed person
•
Integrity of local defense mechanisms
•
Immunological status ( atopy, HLA type)
•
Airway geometry
Site of deposition
•
When airborne particles come in contact with the wall of the conducting
airway or a respiratory unit they do not become airborne again
•
Governs the lung response substantially
•
Mechanisms of dust deposition:

Sedimentation

Inertial impaction

Diffusion

Interception

Electrostatic precipitation
Particle size is important
1.
particles with a size of 5-10 microns are detained in the upper
airways
2.
particles with a size of 3-5 microns – in the mid respiratory tract
3.
particles with a size of 1-3 microns – in alveoli
Clinical approach to the patient
There are two important phases in the workup of any patient with a potential
occupational or environmental lung disease.
1.
General approach: To define and characterize the nature and extent of
the respiratory illness, regardless of the suspected origin

A detailed history

Physical examination

Appropriate diagnostic tools
2. To determine the extent to which the disease or symptom complex is caused
or exacerbated by an exposure at work or in the environment
Chest radiography - is the most important diagnostic test for occupational
lung diseases
Limitations:

The chest radiographic findings can be nonspecific.

„Conventional chest radiography is insensitive, missing as many as 10
to 15 percent of cases with pathologically documented disease.

„Interpersonal variations
ILO – International Classification of radiographs of pneumoconiosis,1971,
2002
1. Film quality : Grades I to IV
2. Small opacities, depending on their size, identified by the letter

round opacities: p (<1.5mm)
q (1.5 –3mm)
r (3 - 10mm)

Irregular opacities:
s (<1.5mm)
t (1.5 – 3mm)
u (3 – 10mm)

Profusion:
Category 0: small rounded opacities absent or less profuse than in category 1
Category 1: small rounded opacities definitely present but few in number
Category 2: small rounded opacities numerous. The normal lung markings are
still visible
Category 3: small rounded opacities very numerous. The lung markings are
partially or totally obscured

Large opacities
Category A: one or more large opacities not exceeding a combined diameter
of 5 cm
Category B: large opacities with combined diameter greater than 5 cm but does
not exceed the equivalent of the right upper zone
Category C: bigger than B
Pleural Abnormalities:

Location

width

extent

degree of calcification
Other abnormal features
Computed tomography
•
Conventional and HRCT scanning are highly sensitive for diagnosis of
pleural diseases and useful for improved visualization of parenchymal abnormalities.
•
„HRCT findings are usually non specific, but occasionally certain
features and distribution pattern may suggest a specific cause and may help narrow
the differential diagnosis
Silicosis

Silicosis is lung disease caused by inhalation of fine silica dust; the dust
causes inflammation and then scarring of the lungs. Scarring shows up on chest xray. Silica is silicon dioxide, the oxide of silicon, chemical formula SiO2

SiO2 is the most abundant mineral on earth; comprises large part of
granite, sandstone and slate.

Silicosis is one type of pneumoconiosis, the medical term for lung
scarring from inhaled dust. Pneumoconiosis can also occur from inhaled asbestos
(asbestosis), coal (coal workers’ pneumonconiosis), beryllium (berylliosis), and
other respirable dusts.

There is no effective treatment for any pneumoconiosis, including
silicosis
Any work that exposes silica dust:
◦
Mining, stone cutting, quarrying, road and building construction, work
with abrasives, glass manufacturing, sand blasting, also, some hobbies can involve
exposure to silica (sculptor, glass blower)
The firstworst incidence of silicosis was recorded in the USA in 1930-1931 on
the construction of Hawk’s Nest Tunnel in Gauley Bridge, West Virginia. It was
called the worst industrial accident in US history. At least 764 tunnel’s workers died
from silicosis. Hawk’s Nest disaster led to Congressional hearings in 1936 and new
laws, protecting workers in many states.
Full description of silicosis by Bernardino Ramazzini (1633-1714) in early
18th century.Citation: “...when the bodies of such workers are dissected, they have
been found to be stuffed with small stones.” Diseases of Workers
(De MorbisArtificumDiatriba, 1713).
On pathology:Fibrotic nodules develop by a particular process in which
fibrous tissue is laid down in concentric rings around a central core of silica particles
as an onion
The main Symptoms in patients with silicosis

shortness of breath while exercising

fever

occasional bluish skin at ear lobes or lips

fatigue

loss of appetite
Three ‘types’ of silicosis

Simple chronic silicosisFrom long-term exposure (10-20 years) to low
amounts of silica dust. Nodules of chronic inflammation and scarring, provoked by
the silica dust, form in the lungs and chest lymph nodes. Patients often asymptomatic,
seen for other reasons.

Accelerated silicosis (= PMF, progressive massive fibrosis) Occurs
after exposure to larger amounts of silica over a shorter period of time (5-10 years).
Inflammation, scarring, and symptoms progress faster in accelerated silicosis than in
simple silicosis. Patients have symptoms, especially shortness of breath.

Acute silicosis From short-term exposure to very large amounts of silica
dust. The lungs become very inflamed, causing severe shortness of breath and low
blood oxygen level.
Silicosis – associated risks

Having silicosis increases risk of contracting tuberculosis & lung
cancer.

Degree of increased risk is highly variable; depends on several OTHER
factors, including immune system & exposure history (for TB), and amount of lung
scarring, age & smoking history (for cancer).

Silicosis also strongly associated with scleroderma and rheumatoid
arthritis.

Other associations less well established: lupus, systemic vasculitis, endstage kidney disease.
Diagnosis of silicosis is based on
•
Abnormal chest X-ray or chest CT scan
•
History of significant exposure to silica dust
•
Medical evaluation to rule out other causes of abnormal x-ray
•
Pulmonary function tests
•
Lung biopsy rarely used
Silicosis can be mis-diagnosed as something else
Silicosis can mimic:
◦
Sarcoidosis (benign inflammation of unknown cause)
◦
Idiopathic pulmonary fibrosis (lung scarring of unknown cause)
◦
Lung cancer
◦
Several other lung conditions (chronic infection, collagen-vascular
disease, etc.)
Can usually make right diagnosis with detailed history (occupational &
medical) or, rarely, a lung biopsy.
Treatment

Early revealing and change of occupation to industry without dust.

Oxygen therapy to improve lung ventilation.

Corticosteroids are used in the period of fast progression, in Rheumatoid
Silicosis.

Treatment of Heart failure

Treatment of Complication (Pleuritis, Pneumonia, Tuberculosis)

Symptomatic Therapy.
Silicatosis (Asbestosis)

Parenchymal lung fibrosis with or without pleural involvement due to
inhalation of asbestos fibres.

5- 20 years to develop

Inflammation from fibres causes scarring (fibrosis) and stiffening of the
lung. This causes less oxygen exchange. Damage leads to bronchitis, bronhiectasis.

Damage leads to pleural changes (pleuritis, spikes, enlargement of
lymph nodes at the lung hila (containing asbestos).

It is more dangerous than silicosis as it predisposes to bronchogenic
carcinoma and mesothelioma of the pleura and peritoneum

Symptoms – shortness of breath, a dry, persistant cough , chest
tightness, deformed, club-shaped fingers
Diagnosis of Asbestosis
Is based on Chest X- Ray :
Interstitial pneumoscelerosis
Diagnostic Particularities:
a) In sputum - asbestos bodies
b) In skin - asbestos Warts (containing asbestos)
Frequent Complications of asbestosis

Bronchogenic carcinoma

Mesothelioma
Caplan's syndrome (or Caplan's disease) is a combination of rheumatoid
arthritis and pneumoconiosis that manifests as intrapulmonary nodules, which appear
homogenous and well-defined on chest X-ray
Caplan's syndrome presents with

Cough, shortness of breath

features of rheumatoid arthritis (painful joints and morning stiffness)

Examination should reveal tender, swollen MCP joints and rheumatoid
nodules

Auscultation of the chest may reveal diffuse rales that do not disappear
on coughing or taking a deep breath.
Other types of occupational lung disease
Byssinosis

Byssinosis is a narrowing of the airways caused by inhaling cotton, flax,
or hemp particles.

The substance or substances in the material that cause the disease are
not known, but it is believed that the protein component rather than the cellulose or
mineral constituents is responsible
Hypersensitivity Pneumonitis

Hypersensitivity Pneumonitis (also referred to as “extrinsic
allergic alveolitis”) is an immunologic-induced, non-IgE mediated inflammatory
pulmonary disease. It affects primarily the interstitium, alveoli, and terminal airways,
and is caused by prolonged, repeated inhalation of organic dusts or certain chemicals
(Farmer’s lung, Bagassosisetc.)
Occupational Asthma

Reversible airflow obstruction caused by workplace exposures

With latency period (sensitization)

Without latency period (irritant)

Causes: a broad group of vegetable, animal products, chemicals, metalsreferred to as “asthmagens”
“New” Occupational Lung Diseases
Popcorn workers lung

Obstructive airways disease, some with bronchitis obliterans

Caused by a ketone (diacetyl) in the artificial butter flavoring used in
microwave popcorn processing
VIBRATION DISEASE
Vibration disease (VD) is a professional disease, the main etiological factor of
which is industrial vibration. The favourable background for the development of the
disease there are the following concomitant occupational factors of risk: noise, super
cooling, significant muscle tension of shoulder, forced position of body.
Usually vibration disease is met among the workers of machine building,
metallurgical, aircraft, shipbuilding, mineral resource industries, and also in transport
and agriculture. Mainly among those workers, whose character of work is related
with the long influence of vibration during the use of hand mechanic tools of
percussion action.
The vibration is the mechanic oscillations that repeat periodically and are
characterized by the frequency measured in hertz (Hz), vibrovelocity (m/s) and
amplitude (cm).
There are three types of vibration: low-frequency (8 – 15 Hz), mediumfrequency (16 – 64 Hz), high-frequency (more than 64 Hz).
Dangerous for the development of disease is the vibration with the frequency 16
– 250 Hz. The women are very sensible to the vibration (the influence to the fetus is
very dangerous), the teenagers, people elder than 40 and people with neural disorder
also are very sensible. Mostly this illness is revealed (40%) among the workers,
whose length of service is 10-15 years.
According to the character of influence to the organism there is local,
general and combined vibration.
During the local vibration the transmission of mechanic oscillations to the body
is realized through the arms. Most often this etiologic factor we can see among the
face-workers, chasers, drillers, tunnellers, polishers, grinders, wood-cutters.
The sources of the general vibration are the vibroplatform, the table vibrator, the
forming and concrete-laying machines, the floor of weaving-mills, agricultural
machines (tractors, combines), excavators, vehicles (airplanes, helicopters, sea and
river ships).
The combined vibration is a combination of local and general. For its turn, it can
be with the advantage of local influence during the work with hand tools, when the
transmission of vibration on the worker’s body is realized not only through the arms,
but also through the legs, breast, back and other parts of body, depending on the
posture during the work and the construction of instrument. In other cases the general
influence can prevail, for example, during the work on vibroplatforms with
simultaneous floating of concrete mix.
Vibration has negative influence on all the tissues of the organism, but most of
all on the neural and bone tissue; the last is a good conductor and resonator of
vibration.
Classification of vibration disease:
1.
From influence of local vibration.
2.
From influence of “combined” vibration
3.
From influence of general vibration
According to the intensity’s degree of pathologic process symbolically mark out
4 stages of disease:
I – initial;
II – moderately expressed (dystrophic disorders);
III – expressed (irreversible organic changes);
IV – generalized
Clinical syndromes:
1)
angiodistonic
2)
angiospastic
3)
syndrome of vegetative polyneuritis;
4)
syndrome of vegetative myofascitis
5)
syndrome of somatic neuritis (cubital,
median), plexitis, radiculitis;
6)
diencephalic with neurocirculatory disturbance;
7)
vestibular
Diagnostics of vibration disease
The inspection of patient in a clinic must be begun with the purposeful
questioning about the conditions of work, feature of his labour activity.
At finding out of professional anamnesis it is necessary to take into account,
how long the worker works on this plant or factory. It is necessary to find out,
whether he had the contact with other occupational hazards.
Collecting the complaints of the patient of it is very important to pay attention to
the characteristic signs of disease: albication of fingers of hands on a cold (its
duration and localization); aching pains in extremities, paresthesias; chilling of hands
and feet, muscle weakness, headaches, dizziness, bad sleep, crabbiness, pains in a
heart and stomach.
Characterizing the state of CNS and presence of polyneurotic syndrome with the
phenomena of angiospasm of peripheral vessels, which take basic place in the clinical
picture of vibration disease, it is necessary to examine in detail the upper and lower
extremities, paying attention to the colour of skin, configuration of fingers, expressed
secretory disturbances, temperature of skin, state of perceptible sphere. It is necessary
to examine internal organs. Foremost it touches the cardio-vascular system, detection
ofangiodistonic, angiospastic syndromes,
and
manifestation
of neurocirculatory dystonia.
It is necessary to pay attention to the additional signs which indicate on
propensity of vessels to the spasm or atony. Often the appearance of hands, without
the results ofcapillaroscopy, enables to suspect the change of vascular tone of
capillaries. Albication of hands is typical for I stage, purple-cyanotic color - for II III stage of disease. Sometimes it is possible to expose the edema of hands, expressed
hyperhidrosis and so called "lace" picture on hands, which is characterized that on the
red-cyanotic background of palm's surface there are plural pale points or spots. These
are spastically modified capillaries which are surrounded by capillaries in a state
of atony.
The diagnosis of vibration disease is proposed on the basis of the collected
complaints, anamnesis of disease and life, study of professional route, sanitary and
hygienic description work conditions.
The typical additional signs of vascular disorders which confirm a diagnosis are:
asymmetry of arterial pressure, symptom of "white spot", Pile’s symptom, test on
reactivehyperemia, test of Boholyepov, cold test.
Medical treatment of vibration disease must be realized in complex with the
account
of
clinical symptomatology.
Application
of vasorelaxants, ganglionic blockers and physiotherapy methods is effective.
During VD conditioned by the influence of local vibration, which flows mainly
with neurovascular disorders and pangs, are recommended the ganglionic blockers
(Gexameton, Benzogexoniy) with the small doses of central anticholinergic drugs
(Difacil, Aminazin, Amizil) and vasorelaxants (Nicotinic acid, No-shpa, Novocaine).
Difacil (spasmolytin) - 1% solution (s-n) in 10 ml i/m (intramuscularly) every
other day, in the course there are 4 - 5 injection with an interruption 2 -3 days. In
general it needs 2 - 3 courses. Difacil can be alternated with Novocaine 0,5% s-n i/v
(intravenously) in 5 - 10 ml every other day during 10 days. Also they
apply Aminazin, Amizil, Galidor, No-shpa during
10
12
days. From
antiadrenergic Melildof (Dopegit) is recommended. Are indicated paravertebral
blocks of 0,25% s-n of Difacil 40 ml and 0,25% s-n of Novocaine 40-50 ml, or 0,25%
s-n of Lidocaine. For medical treatment of asthenoneurotic syndrome indicate
sedative (valerian, motherwort, Novopasit) and tonics, and also biogenic stimulators
(aloe, glutamic acid, fibs, plazmol, ginseng tincture, vitreous body, eleuterococ). For
the
removal
of
pain
syndrome: Analgin, nonsteroid antiphlogistics (Ibuprofen,Voltaren, Indometacin, mef
enamic acid, Butadion). For the improvement of circulation (peripheral, coronal and
cerebral) of blood indicate the medicines which extend coronal vessels and improve
the
cerebral
circulation
of
blood: Devincan, Vincapan, Apresin, Paverin hydrochloride, Aprofen, Cinarizin, Pir
acetam, Cavinton. For the increase of the tone of parasympathetic nervous system,
reduction
of
disturbances
at
vegetative-sensory
polyneuropathy
prescribe: Prozerin, Oxazil, Galantamin. For the improvement of microcirculation
are indicated: ATF, Parmidin, Riboxin, anabolic hormones - Retabolin, Perabol. With
the purpose of improvement of protein metabolism prescribe: Unitol,Penicilamid.
A good effect has application of medicines which normalize vein
tone: Venoruton, vein vasodilators - nitrates (Nitrosorbit, Nitroglycerine), arterial
vasodilators - Apresin, antagonists of calcium - Nifedipin, Corinfar, Adalat.
From tonics is effective introduction of 40% s-n of glucose, calcium gluconate,
calcium chloride, preparations of bromine, caffeine.
At VD a vitamin metabolism is violated, especially due to the deficit of vitamins
of group B and C. Because of it prescribe: ascorbic acid, vitamins B1, B12, B6. They
can cause a sensitizing of organism; therefore in such cases desensitizers are
prescribed: Dimedrol, Pipolfen, Suprastin, Diazolin, Fencarol, Tavegin.
At susceptibility to angiospasms a vitamin PP, which has vasorelaxants effect, is
indicated.
Physiotherapy methods include: electrophoresis with 5% s-n of Novocaine or
2% s-n of Benzogecsoniy on the hands or collar area. At polyneurotic syndromes
apply high-frequency electrotherapy (UHV) on collar area - 15 procedures. General
ultraviolet irradiation by small and suberithematic doses - 10 sessions.
A good effect is observed at application of acupuncture. At the lesion
of locomotor system are indicated: marsh, paraffin, ozocerite applications at a
temperature +40 - +45°, and also balneotherapy with application of hydrogen sulfide,
radon, oxygen baths at a temperature +37°, during 10 - 15 minutes. Also remedial
gymnastics, massage of hands and collar areas are indicated.
Ill people are sent to sanatorium-and-spa treatment in health
resorts: Yalta, Yevpatoriya, Odessa, Khmelnic, Berdyansk.
Prophylaxis
In the prophylaxis of vibration disease reduction of the harmful influence of
vibration on the organism of worker is most essential, and consequently a creation of
new instruments and equipment, which would generate vibration within the limits of
possible norm. An important measure is introduction to construction of mechanisms
and instruments, devices which lower or extinguish the vibration.
A great importance for warning of vibration disease has the correct organization
of labour.
Periodic medical examinations, the basic task of which consists in warning of
the negative influence of professional factors on the organism of workers, early
recognition and detection of vibration disease, belong to the prophylactic measures.
The contra-indications to the employment on the work related with influence of
vibration are the chronic diseases of the peripheral nervous system, obliterating
endarteritis, Raynaud's disease, disease of locomotor system, marked asthenic states,
expressed
vegetative
dysfunction, vagopaties with susceptibility to angiospasms, stenocardia, hypertensive
disease of ІІ -III stages, disease of endocrine glands with stable disturbance
(saccharine diabetes), stomach and duodenal ulcer, neuritis, polyneuritis, stable
hearing loss of any etiology, otosclerosis, chronic diseases of female breeding organs.
Periodic medical examinations are realized not rarer once in 12 months with
participation of internist, neurologist, otolaryngologist. At the inspection it is
necessary to realizecapillaroscopy, measuring of skin temperature, cold test, to
explore a vibration, pain sensitiveness, if necessary radiography of hands, spine.
II. OCCUPATIONAL DISEASES BOUND WITH ATMOSPHERIC
PRESSURE CHANGES
Altitude sickness
The altitude sickness is a disease that results from a considerable and fast
decrease of partial pressure of oxygen (ð02) in ambient gas medium. In 1918
Schneider had offered to aggregate pathologic conditions that arise in time of flight
and climb up an altitude in a unified nosological unit that have received a title of
altitude sickness. It originates in pilots, and also in people, who work on high-level
regions.
Etiology and pathogenesis. Main cause of altitude sickness originating is an
acute oxygen deficiency. Oxygen deficiency development is predetermined by
reduction of barometric pressure with obligatory fall O2 in air or decrease of oxygen
contain in air or in man-made gas medium of hermetically sealed rooms.
Clinic. Two basic forms of altitude sickness are marked out: collapse and
unconscious. The collapse form of altitude sickness originates practically at 3 % of
able-bodied people in 5 - 30 minutes after altitude-chamber ascent on an altitude
of 5000 m. It originates in 25 % cases for persons with functional failure of
cardiovascular system regulation, and at 10-15 % cases for a practically able-bodied
people after ascent on the altitude of 6000 - 7000 m. At that a general weakness,
feeling of fever in all body or only in a head occurs, vision changes, air deficiency is
felt, giddiness and loss of consciousness come up. Exterior of ill person, his/her
behavior changes: paleness of face dermal cover comes up, sweating increases,
features of face are sharpened, and it takes a suffering view. Motion activity is
increased at first, and then delayed; a pose becomes constrained, a look is long, fixing
on separate subjects. Attitude to surroundings becomes indifferent. Consciousness
remains saved for continuous time, but all instructions of doctor are performed slowly
and as if reluctantly. If a sufferer will not be supplied with a normal oxygen feed,
his/her) condition can sharply worsen – a loss of consciousness will be set in.
Frequency of cardiac contractions becomes less often, arterial pressure is reduced,
and that testifies a development of collapse form of altitude sickness. Unconscious
form often arises without any precursors. Ill person does not feel unpleasant
sensations, loses feeling of adequate attitude to external situation and own condition,
the loss of consciousness comes suddenly. In some cases attacks of clonic cramps
precede to consciousness loss. Loss of consciousness at this form of altitude sickness
refers to group of homeostaticunconsciousnesses, as its cause is hypoxemia –
considerable decrease of blood saturation with oxygen. At that a cerebral blood
circulation in some time after loss of consciousness remains on a rather high level,
therefore a renewal of normal supply of organism with oxygen results in recovery of
consciousness and disappearance of all symptoms of altitude sickness within 10-20
seconds.
Treatment. It is necessary to transfer a sufferer with altitude sickness to
breathing by oxygen or mixture of oxygen with 3-5 % contents of carbon dioxide; it
is the only reliable method of this disease treatment. The oxygen therapy for fast and
full recovery of health in light cases is sufficient. Except for the oxygen therapy it is
necessary to use a medicinal therapy at high-gravity forms of altitude sickness, if a
sufferer is unconscious during continuous time or if a loss of consciousness arises
multiply times and is accompanied by attacks of cramps, vomiting. Citramonum,
caffeine, camphor, cordiaminum, strophanthin, lobeline or cytitonum are prescribed
with this purpose. Drugs withdehydrational properties (mannitol, dextrane, and
glucose) are recommended for a preventive measures and elimination
of posthypoxic brain hypostasis. Heat exchange. It is necessary to take into
consideration nature of changes and feature of work at solution of problems,
connected with capacity for work. Experiencing of light forms of altitude sickness
that has not resulted a health condition in nonperishable negative changes later on is
not contraindication to work on a profession. Expressed and nonperishable changes
result in disablement. Medical social commission of experts determine a degree of
decrease of capacity for work, solve a problem concerning necessity of person
transfer to disablement, give recommendations concerning a training for a new
profession with allowance for degree of manifestations of occurred changes.
Preventive measures. The most effective way of preventive measures of
altitude sickness is usage of oxygen equipment that supports normal entry of oxygen
in organism. It is necessary to perform trainings in conditions of an altitude chamber:
regular ascents up on the altitude, which increases step by step (from 3 000 up to 5
000 m), and also under high-level conditions for increase of resistance to altitude
sickness. Preliminary and periodic medical examinations of aircrews are of great
importance. Contraindications to ascent to altitude are any lesions in a central
nervous system, hypophysis and endocrine disorders, cardiovascular diseases, organs
of touch and alimentary glands.
Decompression sickness
Some technology processes are carried out under conditions of heightened
atmospheric pressure. For example, a drifting of horizontal and vertical underground
excavations through watered seams or fulfillment of work under water that is possible
only under condition of water forcing out from an air working chamber using
compressed air. Pneumatic work is performed in special units named torsion boxes
and they are most widespread at building bridges and dams, foundations under
various facilities, tunnels, undergrounds, in coal and mining industry and so on.
Influence of heightened atmospheric pressure is testing with help of divers and scuba
diving. The caisson disease is a pathological condition that develops owing to
formation of gas bubbles in blood and tissues in case of decrease of external
respiration (in a man on leaving caisson and emergence).
Etiology and pathogenesis. Caisson sickness is a consequence of transition of
gases of blood and tissues from dissolved condition in free one – similar to gas - in
case of decrease of environment atmospheric pressure. At that, gas bubbles are
formed, they destroy normal blood circulation, stimulate nervous endings, deform
and damage tissues of organism. Main part of general pressure of gases in lungs and
consequently blood and tissues falls on a portion of nitrogen, a physiologically inert
gas that does not take participation in gaseous exchanges. High partial pressure of
nitrogen in lungs, its physiology and non-reactivity predetermine its basic role in
formation of gas bubbles in case of decompression development. There are two basic
types of bubbles. The first on include bubbles located outside of vessels, formation
and return development is determined by process of diffusion - exchange of gases
between a bubble and medium that surrounds it. The bubbles located inside tissues,
definitely refer to this type. They are capable to enlarge and press on tissues that
surround them, causing their deformation, and that invokes sensation of pain in
patients. Mechanism of development of sensations of muscular-articular
decompression pain at patients has such characteristics.
The second type involves gas bubbles, evolution of which is conditioned not only by
processes of diffusion, but also by junction of one bubble with another or, to the
contrary, by its splitting into even finer bubbles. They join one another, being formed
in venous channel, that gives possibility for acute aeroembolism development in
circulatory system.
Clinic. Three degrees of gravity of a decompression sickness are marked out:
mild, mean and high-gravity. Itch of skin, eruption, non-acute pain in muscles, bones,
joints and along nerve trunk is characteristic for the mild degree. More often,
continuous pain arises in one or several joints of extremities, in particular in knees,
shoulders, and also inradiocarpal, elbow joints and ankles. The pain has no concrete
localization. Most of all it is felt around of joint, being diffused to all directions from
it. The pain, as a rule, strengthens at palpation of joint and bending of extremities.
Joints and muscles experiencing the greatest physical loadings are involved in the
process most often. Itch of skin is felt on a body or on proximal segments of
extremities. It reminds itch of skin after a bite of an insect. Some portions of skin
have mottled pattern due to skin vascular embolism. Gas accumulation in hypodermic
gives start to development of hypodermic emphysema. The disease of the mean
degree of gravity is characterized by disease of an internal ear, gastrointestinal tract
and organ of sight. First of all syndrome Menyera is formed as a result of gas bubbles
origination in labyrinth of internal ear. Acute weakness, gravity and headaches are
watched in a clinical picture. These signs integrates with a loss of consciousness,
vomiting, buzzing in the ears, and decrease of hearing. Strong paleness of dermal
covers, heightened hidrosis appears. Patients complain that all subjects are revolved
before eyes; a minor turn of head strengthens agonizing sensations.
There is a possibility of consciousness loss. Gastrointestinal lesions are characterized
with accumulation of gas in intestines, vessels of mesentery and are accompanied by
arise of strong abdominal pain, often defecation. Palpation of abdomen is agonizing;
it is strained. Visual acuity is reduced and accompanied by dilatation of pupils and
oppression of their reaction on light. The high-gravity degree of caisson sickness is
met today seldom. It is characterized by formation of emboluses in vessels of central
nervous system, heart and lungs. Patients complain on general weakness and
weakness in legs, sharp coughs, strong pain in thorax, in particular at breathing,
asphyxia. Clinical signs of oedema of lungs occur in due course. A significant
amount of gas bubbles of different size that produce lesion of cardiovascular activity
is accumulated in cavities of right heart and in vessels of lungs in case of originating
of multiple aeroembolism. Thus paleness, strong weakness, often and surface
breathing is marked in patients: arterial pressure drops. Pulse falls down, dermal
covers gain cyanotic tint. Loss of consciousness can be set at expressed phenomena
of hypoxia. Myocardial and lung infarction is probable. The cerebral lesions are
conditioned by gas emboluses in brain. Weakness, headache arises after a short-lived
latent period. Sensitiveness of one half of body disappears in light cases, and
phenomena of paralysis arise in more gravity cases: speech is lost; signs of facial
nerve paresis and paraparesis of lower extremities appear. It is accompanied by
distress of urination and defecation.
The chronic decompression disease is determined. Two forms of
it aremarked out: primary and secondary. The primary chronic decompression
sickness develops slowly. Deforming osteoarthrosis is the main clinical manifestation
of this form. The secondary chronic form represents a complex of pathological
changes owing to experienced acute caisson sickness. Its main clinical symptom
is aeropathic myelosis and Meniere's syndrome. At chronic form of the disease,
gas embolas are localized in different organs, mainly in bones. At first the clinical
picture flows without symptoms both permanent pain symptom and lesion of function
of extremities arise only at complication of the process by deforming osteoarthrosis.
Head and proximal ending of diaphysis of thigh are violated at the first turn. After
that, head and upper part of diaphysis of shoulder, then distal parts of thigh, proximal
endings of shinbone, lower endings shoulder and radial bones are struck.
Diagnosis of caisson sickness is established on a basis of the characteristic
complaints and clinical symptomatology that come up after decompression.
Occurrence of dermal itch, pain sensations, Meniere's syndrome, paralyses, sudden
development of collapse - all this with allowance for the preceding decompression is
a direct evidence of caisson sickness.
Treatment. A radical method of a caisson sickness treatment is recompression
that influences patient by heightened pressure in a recompression chamber. The
method is based on the fact that gas bubbles located in patient’s organism decrease
their volume and solve atrecompression. The recompression renders assistance for
dissolution of the
bubbles, that is it eliminates etiological factor of illness. The medical recompression
is carried out under a special program. Symptomatic treatment is used depending on
patient’s condition: stimulation of cardiovascular system, warming, oxygen, means
directed on struggle with pain, with a possible oedema of lungs. Application of a
hyperbaric oxygenation gives quite good outcomes.
Verification of the ability to work. The sick-leave is given for a period of
treatment for 10 days at mild degree of illness. Patient can be temporarily given a
work outside of heightened atmospheric pressure and other unfavorable factors
operation with issue of a labor sick-leave in case if further treatment in out-patient
conditions is necessary. Return the sufferer of caisson sickness of mean gravity to the
same work is authorized after a period of temporary incapacity for work. Availability
of complications in the form of firm organic changes on the part of organ of sight and
gastrointestinal tract leads to a steady disablement with a rather large list
of counterindicative kinds of labor activity.
The labor forecast at a high-gravity degree of a caisson illness is always unfavorable.
It is necessary to send patients on commissioning for disablement degree definition
andrehabilitational measures elaboration.
Preventive measures. The warning of decompression disease is envisioned, first
of all, by observance of rules of work in caisson-box. So, the maximal pressure
during their realization should not exceed 3.9 atm. A working day in a caisson box is
divided on two parts with a rest between them not less than 9-10 hours outside of a
caisson box. General number of working hours during a day, including time of
locking and unlocking, is ranged from 6 h till 2 h 40 minutes depending on pressure
in a caisson box. Breathing with oxygen, struggle against overcooling of workers is a
preventive action against caisson sickness. An ambulatory or a medicine post with a
day-night duty of medical staff is organized for the well-timed and qualified health
services on each site of construction where the caisson work is realized. Isolation
ward on the occasion of a decompression sickness, medical airlock can be at a
medical center. Persons permitted to decompression and diving jobs should pass
preliminary medical examination. Contraindications for admittance for these jobs is
hypertensive disease, pulmonary tuberculosis, respiratory tract lesion of not
tubercular etiology, peptic ulcer of ventricles and duodenum, illness ofnephroses and
urinary bladder, sugar Diabetes, and excessive stoutness. All people working in a
caisson box are subject to weekly medical examination with participation of doctor therapeutist and otolaryngologist.