BOS - is a leading sign, which brings together
a group of acute, recurrent and chronic lung disease, but it is not an
independent nosological form and could not appear as a diagnosis. It should be
noted that the BOS is not synonymous with bronchospasm, although in many cases,
bronchospasm is important, and sometimes a leading role in the genesis of the
disease. Usually BOS is diagnosed in children of the first four years of life,
but can be diagnosed in older age.
In the
genesis of bronchial obstruction are different pathogenetic mechanisms, which
can be divided into:
• functional or reversible (bronchospasm, inflammatory infiltration,
edema, mucociliary insufficiency,
hypersecretion of viscous mucus)
• irreversible (congenital stenosis of the bronchi, their obliteration,
etc.).
Peculiar features of
the children of the first three years of life have played the certain role in
the development of bronchial obstruction:
Þ
narrowness of the bronchi
and the entire respiratory system greatly increases
aerodynamic resistance. Thus,
swelling of the bronchial mucosa by only 1mm
causes an increase in
resistance to air flow in the trachea more than 50%.
Þ
softness of cartilage
bronchial tract
Þ
lack of rigidity of the
bone structure of the thorax, freely reacting indrawing of
accommodating places to
increase the resistance in the airways
Þ
particular position and
the structure of the diaphragm.
BOS in children may be substantially
aggravated by structural features of bronchial wall, such as a large number of
goblet cells that produce mucus, and
increased
viscosity of bronchial secretions associated with high levels of cialic acid.
Early childhood is characterized by the
imperfection of immunological mechanisms: significantly reduced the formation
of interferon in the upper respiratory tract, serum immunoglobulin A, secretory
immunoglobulin A, and reduced functional activity of T-immunity system.
Influence
of premorbid factors of acute obstructive bronchitis:
-
Toxicosis of pregnancy - Dystrophy
-
Obstructed labor
- Hyperplasia of the thymus
-
Hypoxia in childbirth - Early
artificial feeding
-
Perinatal encephalopathy - A variety
of abnormalities of
-
Prematurity constitution
-
Burdened allergic history - The
respiratory disease at the age
-
Bronchial hyperreactivity of
6-12 months
-
Rickets -
The presence of atopy
A major disadvantage is the
pollution of the environment.
The scheme of the basic mechanisms of bronchial obstruction.
1. material into bronchi (foreign body, mucous etc.)
2. edema of bronchial mucous membranes (obstructive dronchitis)
3. retraction of bronchial muscles (bronchial asthma)
4. compression out of bronchus (mediastinum tumor, dilatation of
pulmonary artery
at congenital heart diseases)
Etiology
BOS usually is infectious-allergic nature. Among the viruses that most
commonly cause BOS are respiratory syncytial virus (50%), then parainfluenza,
rarely - influenza and adenovirus. Recently, in the development of BOS big role
is due to intracellular pathogens. According to modern data, chlamydia and
mycoplasma infection are determined in 20% of children with BOS. According to
different authors, about 20-25% of bronchitis in children occur as an acute
obstructive bronchitis (AOB), which is significantly higher than in adults.
Especially high frequency of AOB
is as a manifestation of acute respiratory infections (ARI) in infants. This is
due to the fact that in the first half year of life 80% of the entire surface
of the lungs is small bronchi (diameter less than 2mm), whereas a child 6 years
old - already 20%. According to the Poiseul rule resistance of airways is
inversely proportional to their radius in the 4-th degree. Obstructive syndrome
of is the more probable in the distal lesion of the bronchi.
Pathogenesis
Regulation of bronchial tone is
controlled by several physiological mechanisms, which include complex
interactions receptor-cell component and mediators system. These include
cholinergic, adrenergic, neurohumoral regulatory system and, of course, the
development of inflammation. Interleukin-1 is the main mediator, initiating the
acute phase of inflammation. It activates a cascade of immune reactions that
contribute to the exit in the peripheral blood of type 1 mediators (histamine,
serotonin and others).
Histamine is released during an
allergic reaction in the interaction of allergen with allergen IgE. In addition
to histamine, a type 2 (eicosanoids) play an important role in the pathogenesis
of inflammatory mediators. Under the action of cyclooxygenase from arachidonic
acid there are synthesing prostaglandins, thromboxane and prostacyclin, while
under the influence lipooxidaze - leukotrienes.
The result is increased vascular
permeability, leading to swelling of the mucous membrane of the bronchi,
hypersecretion of viscous mucus, the development of bronchospasm. The main
mechanism in the pathogenesis of bronchospasm is activation of cholinergic
nerve fibers, leading to increased production of acetylcholine and increasing
concentrations of gualinatecyclase, which promotes the flow of calcium ions
into smooth muscle cells, thereby stimulating of bronhoconstriction.
Stimulation of α2-adrenoceptor catecholamines, as well as an
increased concentration of cAMP decreases the manifestations of bronchospasm.
Clinics of BOS
The clinical picture of BOS in
children is primarily determined by factors of bronhoconstriction. As noted
above, in most cases BOS is associated with manifestations of acute respiratory
viral infection (acute obstructive bronchitis). So body temperature is rised up
early, catarrhal changes in the upper respiratory tract and violation of
general condition of the child appear. The severity and the nature
largely vary depending on what the agent has led to the disease. Signs
expiratory breathing difficulties may occur as the first day of illness, and in
the process of viral infection (3-5-day sickness). Gradually there is increasing the breathing
frequency and
duration of exhalation. Breathing becomes noisy and whistling, which is
due to the fact that with the development of hypersecretion, the accumulation
of secretions in the lumen of the bronchi due to shortness of breath and fever
change viscosity of the secret - he "dries up", which leads to buzzing (low) and whistling (high)
wheezes.
The defeat of the bronchi is
widespread, and therefore hard breathing with dry whistling and buzzing
wheezing are equally audible over the entire surface of the thorax. Rales may be heard at a distance.
The younger the child, the more frequently he has, in addition to dry, the
moist medium bubbling rales. If in the genesis of bronchial obstruction a major
role plays spastic component, it auscultative data over lungs is generally more
diverse and labile during the day. With increasing dyspnea important role of supporting muscles
becomes increasingly - retraction of the intercostal spaces, epigastric and
supraclavicular fossa, bloating (voltage) of the nostrils. Often there are revealed
perioral cyanosis, pallor of the skin, the child becomes restless, trying to
adopt a sitting position, drawing on his hands.
Respiratory failure more evident than the younger the
child, but usually it is not more than II degree. On physical
examination, in addition to scattered wheezes and hard breathing, there are the
signs of lung swelling: narrowing boundaries of relative cardiac dullness,
boxed shade percussion tone. The
inflation of the lungs is a result of consequence wears small bronchial
branches during expiration, which leads to the so-called ventilation emphysema.
The volume of the lungs increases. The rib cage is constantly in a state of
inspiration, which increases the anteroposterior size.
Changes in peripheral blood correspond to the nature of viral
infection. Bacterial flora is rarely overlapped - not more than 5%.
Radiologically, in addition to strengthening
bilateral lung pattern and expansion of the roots of the lungs there are revealed:
lowness flattened dome of the diaphragm, increasing the transparency of lung
fields, lengthening the lung fields, a horizontal arrangement of ribs on the
radiograph, which mean the signs of swelling of the lungs.
Diseases
accompanied by BOS
There are the following groups of
diseases accompanied by BOS:
•
Diseases of the respiratory system – Infectious-inflammatory diseases (acute
constrictive laryngotracheitis, bronchitis, bronchiolitis, pneumonia), allergic
diseases (obstructive bronchitis, bronchial asthma), bronchopulmonary dysplasia,
malformation of bronchopulmonary system, tumors of the trachea and bronchi.
•
Foreign bodies of trachea, bronchus, esophagus.
•
Diseases of the aspiration genesis (aspiration or obstructive bronchitis) –
gastroesophageal reflux, tracheoesophageal fistula, malformations of the
gastrointestinal tract and diaphragmatic hernia.
•
Diseases of the cardiovascular system – Congenital and acquired (congenital
heart disease with hypertension, pulmonary circulation, vascular anomalies,
congenital Non-rheumatic carditis, etc.).
•
Diseases of the central and peripheral nervous system (birth injury, myopathy,
etc.).
•
Hereditary anomalies of metabolism (cystic fibrosis, α1-antitrypsin
deficiency, mucopolysaccharidosis).
•
Congenital and acquired immunodeficiency states.
•
Rare hereditary diseases.
•
Other states – Injuries and burns, poisoning, the effects of various physical
and chemical environmental factors, pressure on the trachea and bronchi of
extrapulmonary origin (tumor, venereal disease).
Diseases of the
bronchopulmonary system
The most frequently differential diagnosis of
bronchial obstruction syndrome in children is made among the diseases of the
bronchopulmonary system.
BRONCOOBSTRUCTIVE SYNDROME IN PNEUMONIA
The edema
of mucus membrane of bronchial tubes lies in the basis of syndrome,
hyperproductions of phlegm and, in a less measure, bronchospasm, more
frequent on a background of congenital or acquired hyperreactivity of bronchial
tubes are also important factor. This syndrome is identified at acute
bronchopneumonia and is the reason of respiratory insufficiency on a
bronchoobstructive type, which quite often determines severity of the state and
needs adequate oxygent therapy.
Clinic. Increase of temperature of body, trouble or oppression, crabbiness,
pallor of skin with perioral and acrocyanosis, unproductive cough, controlled
from distance wheezes, oral crepitation, shortness of breath, with prolonged
one and hard exhalation, drowning in chest of intervals between ribs, another
areas of chest.
Percussion
reveals the tympanic sound with areas of short sound.
Auscultation: hard
breathing with the prolonged exhalation, dissipated dry and moist wheezes, the
locally loosened breathing with the isolated proof moist wheezes.
Help
on prehospital stage
1.
To provide
access of fresh air.
2.
To release
from squeezing clothes.
3.
Clean oral
cavity and larynx from mucus and
phlegma
Apparatus for cleaning of nose
4.
Oxygentherapy
with clean moistened oxygen through a mask or oxygen pillow.
5.
Inhalation
of dosed aerosol of Atroventi (ipratromium-bromide) 1-2 through spenser.
6. Inhalation of dosed aerosol b2-antagonists of quick actions (Salbutamoli, Ventolini, Berotec) 1-2 doses through spenser 20
minutes during hour. When
it is impossible to make inhalations- syrup, tablets of Salbutamoli or
Terbutalini (Bricaniliу) to children upto 1 year - 1 mg 3 times, 3-6
years – 2 mg 3 times, 7-15 years – 2-3 mg 3 times; Clentuberoli (Spiropent) –
0,005-0,02 3 times; Broncholitini to children upto 3 years– half tea-spoon, 3-10
years 1 tea-spoon, elder 10 years is a 1
dessert-spoon 3 times per days.
7. Euphyllini 3-5
mg/kg - 2,4 % solution of Euphyllini in
that dose
intravenously streamly on 10 ml of 10 %
glucose solution .
8. 3
% solution of Prednisoloni 1-2 mg/kg
intramuscular.
9. Hospitalization.
Help on a hospital stage
1. To provide access of fresh air.
2. To release from squeezing clothes.
3. Sucking with electrosucker mucus and phlegma from
upper respiratory tracts.
4. Oxygenation therapy through a nasal catheter is
the clean moistened oxygen during 20 minutes every 2 hours or 40 % oxygen
constantly.
Oxygenation therapy through a nasal catheter
5. Inhalation
of dosed to the aerosol of Atroventi (ipratromium-bromide) 1-2 dose through
spenser.
6. Inhalation of dosed aerosol b2-antagonists of quick actions (Salbutamoli (Ventolini, Berotec) 1-2 doses through spenser 20
minutes during hour. When it is impossible to make inhalations- syrup, tablets
of Salbutamoli or Terbutalini (Bricaniliу) children upto 1 year - 1 mg 3 times, 3-6 years – 2 mg 3 times, 7-15
years – 2-3 mg 3 times; Clentuberoli (Spiropent) – 0,005-0,02 3 times; Broncholitini to children upto 3 years– half tea-spoon, 3-10
years- 1 tea-spoon, elder 10 years is a 1 dessert-spoon 3 times per days.
7. 3 %
solution of Prednisoloni 1-2 mg/kg of
masses intravenously streamly.
8. 2,4 %
solution of Euphyllini 0,15 ml/kg of mass of intravenously
in drops on
10 %
glucose solution 10–15 ml/kg.
9. Cocarboxilazae
of a 5–10 mg/kg of mass on 5,0 ml of 10 % Glucose solution
intravenously streamly.
10. 5 %
solution of sodium ascorbinati 2 ml/kg of masses of intravenously streamly
on 5,0 ml of
10 % glucose solution .
11. Panangini
0,1 ml/kgh of masses on 5,0 ml of 10 % Glucose solution
intravenously
streamly.
12. In default of effect drops intravenously introduction of Prednisoloni 2 – 3 mg/kg of the masses (Hydrocortisoni 10 – 15 mg/kg) on
10 % Glucose solution a 10 – 15 ml/kg
of mass.
13. Mucolytic
drugs: salt–alkaline inhalations; Lasolvani,Acetylcycteini in inhalations, syrup, tablets;
Bromhexini in syrup, tablets; Mucaltini
in tablets.
Mucolytic
inhalations
14. Vibromassage
of thorax in drainage position with next active aspiration of
phlegm.
15. Alkaline
drink: solution 1 % sodium bycarbonati per day to drink 10 – 12 ml/kg of mass slightly.
