Bronchial Obstruction in Children
Assistant Professor of Hospital Pediatrics
Department of SSMU, Cand.Med.Sci. Ledeneva L. N.
* Bronchoobstructive syndrome (BOS) occurs in children
quite often, sometimes it takes a very severe course.
* The syndrome of bronchial obstruction in children
manifests, as a rule, against a background of respiratory
infection and in the first place, it is a manifestation of acute
obstructive bronchitis and asthma, but it can be a
manifestation of other pathological conditions.
* In most cases, BOS prognosis is serious and depends on
the cause of bronchial obstruction, on the forms of the
disease, timely conducted pathogenetic therapy and
prevention.
The urgency of the problem of
BOS
• In childhood, respiratory diseases occupy one of the first places.
• Hereditary factors, environmental pollution, social factors play an
important role in it.
• In recent years there has been a marked increase in diseases that
occur with an obstructive syndrome, which is very diverse in
nature and may be a manifestation of many diseases.
• Manifestation of the syndrome usually occurs on the background
of acute respiratory viral infection, it takes a severe course and is
accompanied by signs of respiratory failure.
• Early diagnosis of the diseases that caused the obstruction, timely
pathogenetic treatment and prevention reduces or eliminates
clinical manifestations of the syndrome, and thus improves the
quality of life of patients.
The objective of the lecture
• Coverage of modern concepts, the course
and treatment of bronchial obstruction in
children.
The significance of the problem of
BОS
• Inadequate diagnosis
• The lack of a comprehensive program of
monitoring of the patients
• The lack of continuity of treatment in the hospital
and continuing of treatment on an outpatient basis
• The need for rehabilitation and social adaptation
Connection with previous lectures
• Symptom complex of BOS: obstructive bronchitis,
bronchitis caused by atypical flora (chlamydia,
mycoplasma), asthma, cystic fibrosis and other
pathological conditions have close clinical, diagnostic
and therapeutic parallels between them.
Sections of the lecture
1.
2.
3.
4.
5.
Causes and risk factors for bronchial obstruction syndrome.
Mechanisms of formation of bronchial obstruction in children.
Clinical manifestations of the most common diseases in children, that take
their course with obstructive syndrome and their differential
characteristics.
Standard programs for the child’s screening to clarify the etiology of the
disease.
Principles of treatment of bronchial obstruction syndrome in infants.
DEFINITION
• Bronchoobstructive syndrome (BOS) is a symptom
complex associated with impaired bronchial patency
of functional or organic origin.
• In Western literature this clinical symptom complex is
currently called wheezing - wheezing syndrome.
• The term "BOS" can not be used as an independent diagnosis.
BOS is a symptom complex of any disease, the etiology of
which is necessary to determine in all cases of the
development of bronchial obstruction.
• The prevalence of obstructive conditions of the airways is quite high,
especially in children during the first 6 years of life which is associated
with anatomico-physiological features of the respiratory tract in infants.
• Prevalence of BOS on the background of respiratory infections in infants
ranges from 5% to 50%.
• Most often obstructive conditions occur in children with a family history of
allergies, as well as in children, who often suffer from respiratory infections
(more than 6 times).
BOS Clinical Picture
• prolonged exhale
• wheezing, noisy breathing (expiratory dyspnea, BH 50 and
more per minute)
• asthmatic fits
• auxiliary muscles participating in breathing
• poorly productive cough
• decrease in oxygen partial pressure.
BOS Predispose Factors
Anatomical and physiological factors in young children:
• the relative narrowness of the respiratory tract
• hyperplasia of glandular tissue
• rich vascularization of the mucous
• predominantly viscous mucus secretion
• low collateral ventilation
• insufficient local immunity
• relative weakness of the diaphragm
Factors of premorbid background:
• coupled allergic history
• a genetic predisposition to atopy
• perinatal pathology
• bronchial hyperreactivity
• rickets
• malnutrition
• early formula feeding
• respiratory diseases
Environmental Factors:
• unfavorable environmental conditions
• passive smoking
• smoke inhalation promotes disruption of mucociliary clearance, causes
hypertrophy of bronchial mucous glands, destruction of bronchial
epithelium, reduces phagocytic activity of macrophages, reduces the
activity of T- lymphocytes, stimulates IgE synthesis, increases the activity
of the vagus nerve
• in children with alcohol fetopathy atopy develops, mucociliary clearance is
broken, protective immunological reactions are slowed.
Etiology of BOS
• Acute stenosing laryngotracheobronchitis of viral, bacterial
and viral etiology of diphtheria.
• Peritonsillar abscess, retropharyngeal abscess, epiglotit,
congenital stridor, hypertrophy of the tonsils and adenoids,
cysts, hemangioma and papillomatosis of the larynx.
• In infants - aspiration caused by swallowing disorders,
congenital abnormalities of the nasopharynx, chalasia and
achalasia of the esophagus, tracheobronchial fistulas,
gastroesophageal reflux disease.
• Malformations of trachea, bronchi, RDS, cystic fibrosis,
bronchopulmonary dysplasia, immunodeficiency, intrauterine
infection.
• At the 2nd and 3rd year of life BOS occurs in children with
asthma, with foreign body aspiration, during migration of
round helminths, in bronchiolitis obliterans, in patients with
congenital and hereditary diseases of the respiratory system, in
children with CHD, proceeding with pulmonary hypertension.
• However, the main causes of bronchial
obstruction in children are acute obstructive
bronchitis and bronchial asthma!
The pathogenesis of bronchial obstruction
depends on the etiology of the disease. Pathogenetic
mechanisms can be divided into two groups:
1. Functional (reversible). It is bronchospasm,
inflammatory infiltration, edema, violation of mucociliary
clearance, hypersecretion.
2. Irreversible (congenital stenosis of the bronchi and
others).
• The main factor of the pathogenesis of 1 group BOS is inflammation,
which can be both infectious and allergic in children .
• The mediator of the acute phase of inflammation is interleukin-1 (IL-1).
• It is produced by phagocytic cells and tissue macrophages under the action
of infection, allergy and promotes the release of first type mediators
(histamine, serotonin) into peripheral blood.
• These mediators are constantly present in the granules of mast cells and
basophils, that ensures very rapid biological effects.
• Besides histamine, an important role in the pathogenesis of
inflammation is played by mediators of a second type
(eicosanoids) generated during the early inflammatory
response.
• The source of eicosanoids is arachidonic acid, formed of
phospholipids of cell membranes.
• Under the action of cyclooxygenase from arachidonic acid
prostaglandins, thromboxane and prostacyclin are synthesized,
and under the action of lipoxygenase - leukotrienes.
It is due to histamine, leukotrienes and antiinflammatory prostaglandins that we observe:
• enhancement of vascular permeability
• edema of bronchial mucosa
• hypersecretion of mucus viscous
• bronchoconstriction
• Damaged tissues have an increased sensitivity of receptors of
the bronchi to external influences (viral infection, pollutants),
which significantly increases the risk of bronchospasm.
• In damaged tissues anti-inflammatory cytokines are
synthesized, degranulation of neutrophils, basophils,
eosinophils occurs, thereby increasing the concentration of
such biologically active substances as bradykinin, histamine,
oxygen free radicals, which are also involved in the
development of inflammation.
• Thus, the disease process assumes the character of
"vicious circle", predisposes to a long course of
airway obstruction and superinfection!
• BOS is accompanied by an increase in the amount of secretion in the
bronchi and by increase of its viscosity.
• Activity of mucous and serous glands is regulated by the parasympathetic
nervous system, and acetylcholine stimulates their activity.
• Such a reaction is initially of defensive nature.
• However, the stagnation of bronchial content leads to disruption of
ventilation and respiratory function of the lungs, and the inevitable
infection - to the development of endobronchial or bronchopulmonary
inflammation.
• Furthermore, thick secretion may cause obstruction of the respiratory tract
due to the accumulation of mucus in the upper or lower airways.
• In severe cases, atelectasis may develop.
• Edema and hypersecretion of the mucous membrane
of the respiratory tract is also one of the causes of
bronchial obstruction.
• There is a thickening of all layers of the bronchial
wall, which leads to bronchial obstruction.
• At recurrent bronchopulmonary diseases the structure
of the epithelium is disrupted, its hyperplasia and
squamous metaplasia are marked.
• Certainly, bronchospasm, is a major cause of BOS in
older children.
• Thus, there are several basic mechanisms of bronchial
obstruction.
• The share of each of them depends on the reasons for
the disease process and the child's age.
Grouping of bronchial obstruction
About 100 diseases associated with BOS are known . There is no common
classification. Considering the data from the literature, the following groups of the
diseases involving BOS can be defined.
1. Diseases of the respiratory system.
• infectious inflammation (bronchitis, bronchiolitis).
• bronchial asthma
• aspiration of foreign bodies
• bronchopulmonary dysplasia
• malformations of the respiratory system
• obliterating bronchiolitis
• tuberculosis
2. Diseases of the digestive tract
•esophageal chalasia and achalasia
•gastroesophageal reflux disease
•tracheoesophageal fistula
•diaphragmatic hernia
3. Hereditary diseases
•cystic fibrosis,
•deficiency of alpha-1-antitrypsin
•mucopolysaccharidoses
•rickets-like diseases
4. Parasitic infections (toxocariasis)
5. Diseases of the CAS
6. Diseases of the central and peripheral nervous system (birth trauma, myopathy, etc.).
7. Congenital and acquired immunodeficiency
8. The impact of various physical and chemical environmental factors
9. Other reasons (endocrine diseases, systemic vasculitis, Thymomegalia et al.)
From a practical point of view, 4 basic groups
of BOS causes are distinguished:
•
•
•
•
infectious
allergic
obstructive
hemodynamic
•
•
•
•
By duration, BOS can be:
acute (BOS clinical manifestations persist for more than 10 days)
protracted
recurrent
continuously recurring
According to the severity, the obstruction can be identified as:
• mild
• moderate
• severe
• latent bronchial obstruction
Criteria for severity of BOS
•
•
•
•
•
•
wheezing
dyspnea of expiratory character
cyanosis
auxiliary muscles participating in breathing
lung function (LF) and blood gases indices
cough is seen with any degree of BOS
Mild BOS
• wheezing on auscultation
• no breathlessness and cyanosis at rest
• indices of blood gases are within the normal range
• ERF indices (FEV1, PSV) are moderately reduced
• state of health of the child, as a rule, does not suffer
BOS of moderate severity
•
•
•
•
•
expiratory or mixed dyspnea at rest
cyanosis of nasolabial triangle
indrawing of compliant places of the chest
wheezing is audible at a distance
ERF indices are reduced, but CBS is slightly broken (pa О2 is
more than 60 mm Hg., pa СО2 is less than 45 mm Hg.)
A severe course of BOS
• state of health of the child suffers
• it is characterized by noisy shortness of breath with auxiliary
muscles participation
• presence of cyanosis
• ERF indices are sharply reduced
• There are signs of a generalized functional bronchial
obstruction, pa О2 less than 60 mm Hg., pa СО2 more than 45
mm Hg.
Diagnostics of bronchial obstruction
syndrome
In the study of clinical and anamnestic data, you must pay
attention to:
• past illnesses
• the presence of recurrence of bronchial obstruction
• atopy in the family
Newly diagnosed BOS of a mild severity, which has
developed against the background of a respiratory infection,
does not require additional tests.
At recurrent course of BOS, complex surveys should include:
•CBC
•screening for chlamydia, mycoplasma, cytomegalovirus, herpes
and pneumocystis infection
•comprehensive study on the presence of helminths (toxocariasis,
ascariasis)
•allergy survey
•consultation of an otolaryngologist - to children with the
syndrome of "noisy breathing "
Radiography of the chest cavity is not required by the study in
children with BOS. It is performed at:
•suspected complicated course of BOS (atelectasis)
•suspected foreign body
•recurrent course of BOS
•to exclude pneumonia.
According to indications, bronchoscopy, bronchography,
scintigraphy, angiopulmography, CT of the lungs are carried
out. The volume of the survey is determined individually in each
case.
The external respiratory function in the presence of noisy breathing in
children older than 5-6 years is studied obligatory.
Currently, the most widespread is dynamic spirography, which estimates the
"flow-volume" ratio.
The most informative indicators at the presence of airflow obstruction are the
reduced:
1) forced expiratory volume in 1 second (FEV1);
2) peak expiratory flow rate (PSV).
In the absence of overt signs of bronchial obstruction, conducting of a test
with a bronchodilator to eliminate latent bronchospasm is indicated.
Diagnostic algorithm in a child with BOS
1. To establish the presence of bronchial obstruction.
2. To establish the etiology of the disease that caused
BOS.
3. To conduct differential diagnosis with other possible
causes of BOS.
4. To exclude the causes of "noisy breathing
syndrome“ not associated with BOS.
The differential diagnosis of BOS
• Most often, BOS develops in children with SARS and is a manifestation of
acute obstructive bronchitis, but it may be the first clinical manifestation of
asthma or other chronic diseases.
• Sometimes extrapulmonary causes of noisy breathing, such as congenital
stridor, stenosing laryngotracheitis, dyskinesia of larynx, tonsils and
adenoids hypertrophy, cysts and hemangiomas of the throat,
retropharyngeal abscess, etc. are taken as obstructive symptoms.
At repeated episodes of BOS on the background of ARVI, several groups
of factors, most contributing to BOS relapses on the background of
respiratory infection are distinguished:
1.
Recurrent bronchitis, which is often caused by bronchial hyperreactivity,
developed as a result of the survived ARI of the lower respiratory tract.
2.
The presence of asthma, the debut of which coincides with the
development of intercurrent acute respiratory disease.
3.
Latent course of the chronic bronchopulmonary diseases (cystic fibrosis,
ciliary dyskinesia).
Acute obstructive bronchitis (OB)
•
•
•
•
Bronchial obstruction at OB develops on the 2-4 days of ARI already on the
background of marked catarrhal phenomena and unproductive, dry cough.
Dyspnea of expiratory character appears without the expressed tachypnea (40-60
per min), sometimes distant wheezing is in the form of noisy, rattling breathing, at
percussion there is a bandbox sound, at auscultation - the prolonged expiration, dry
whistling (musical) wheezing, mixed moist rales on both sides .
On chest cavity radiographs the increased pulmonary pattern is defined , sometimes
transparency is increased.
BOS continues for 3-7-9 days or longer, depending on the nature of the infection
and disappears gradually subsiding parallel to inflammatory changes in the bronchi.
Acute bronchiolitis
• is observed in children under 2 years old. Most often it is caused by RSinfection.
• affects small bronchi, bronchioles and alveolar passages.
• The narrowing of the bronchi and bronchioles occurs due to edema and cell
infiltration of the mucosa, which leads to the development of severe RF.
• At the same time bronchoconstriction does not really matter, as is
evidenced by the lack of effect of bronchospasmolytic means.
Clinical picture. Severe respiratory failure: perioral cyanosis, acrocyanosis,
tachypnea (depending on age) to 60-80-100 per min., with the prevalence of an
expiratory component, oral crepitation, retraction of malleable sites of the
chest.
At percussion, over the lungs - bandbox percussion sound, at auscultation many small and moist wheezing crepitating rales over all fields of the lungs on
inhalation and exhalation, exhale is prolonged and heavy.
Symptoms develop gradually over a few days, sometimes sharply, on the
background of acute respiratory disease, and is accompanied by a sharp
deterioration in the health state:
paroxysmal cough may occur, vomiting, restlessness;
temperature reaction and symptoms of intoxication are determined by the
course of a respiratory infection.
 at X-ray examination of the lungs, lungs hyperinflation, a sharp increase in
bronchial pattern, low standing of the dome of the diaphragm, the horizontal
position of the ribs is revealed.
Bronchial obstruction persists long enough, at least 2-3 weeks.
Bronchial asthma
• manifest during early childhood in the majority of patients . The initial
symptoms are usually those of BOS character on the background of ARVI.
• BA is often not recognized in time and patients are not treated properly.
• The course and prognosis of BA depend to a large extent on the timely
diagnosis and adequate treatment, so you must pay close attention to the
early diagnosis of the disease.
If the child of the first 3 years of life has:
• - more than 3 episodes of BOS on the background of ARVI,
• - atopic diseases in the family,
• - the presence of allergic diseases,
it is necessary to observe the patient as a patient with bronchial asthma,
including allergic additional survey and the decision on the administration
of basic therapy.
BOS TREATMENT AT ARVI IN INFANTS
Aimed at eliminating the cause of disease
BOS Treatment with ARVI in young children includes:
• improvement of drainage function of bronchi
• bronchodilator and anti-inflammatory therapy
Improving drainage function of bronchi is:
1) active oral rehydration,
2) the use of expectorants and mucolytic drugs,
3) massage
4) postural drainage,
5) breathing exercises.
•
As a drink, alkaline mineral water is used, an additional daily fluid
volume is about 50 ml / kg of body weight of the child.
Mucolytic and expectorant therapy
The goal of this therapy is the liquefaction of sputum, reducing its adhesiveness and
increase the effectiveness of cough.
• If a child has unproductive cough with viscous sputum it is advisable to prescribe
Mucosolvan (Ambrobene, Ambroxol)
• The drug has a pronounced mucolytic and mucokinetic effect, mild anti-inflammatory
action, it increases the synthesis of surfactant, does not increase bronchial obstruction,
practically does not cause allergic reactions.
• Doses: 7.5 - 15 mg 2-3 times a day as a solution or by inhalation.
• For children with obsessive unproductive cough, sputum lack it is advisable to
prescribe expectorant drugs:
- alkaline drink,
- phytopreparations (plantain syrup, coltsfoot broth, Gedeliks, Prospan, Bronchipret
(ivy leaves extracts).
Phytopreparations are prescribed with caution for children with allergies.
A combination of expectorants and mucolytics is possible.
• For all patients with BOS antitussives are excluded.
• Appointment of combined preparations containing ephedrine
(Solutan, Broncholytin) is possible only in rare cases of
overproduction of abundant liquid bronchial secretion, as
ephedrine has an expressed "drying" effect.
• At expressed secretion, mucoregulatory products based on
carbocisteine (Broncatar, Mucodyne, Mucopront) can be used.
• Thus, the program of expectorative and mucolytic
therapy is made individually according to clinical
course of the disease in each patient and should
help to restore a patient’s adequate mucociliary
clearance.
Antihistamines
• The use of antihistamines is indicated only at the occurrence or
at worsening of any allergic reactions.
• Second-generation drugs having no effect on the viscosity of
sputum are favored. Beginning from 6 months of age
Ceterizinum ("Zyrtec") is allowed by 0.25 mg / kg 1-2 times
per day.
• For children over 2 years old, Loratadinum ("Claritine"),
Desloratadinum ("Aerius") can be prescribed, over 5 Fexofenadinum ("Telfast").
Bronchodilator therapy
•
•
•
•
•
Short-acting β2- agonists are used (Salbutamol, Fenoterolum) - drugs of choice.
Preparations are highly selective and therefore have few side effects.
Bronchodilator effect at inhalation use occurs within 5-10 minutes.
A single dose of Salbutamol is 100-200mkg (1-2 doses), via a nebulizer a single
dose may be considerably higher and is 2.5 mg (nebula by 2,5ml 0.1% solution).
Administered by 3-4 times a day.
In severe course of BOS torpid to treatment, as a "first aid treatment“, the
introduction of three inhalations of short-acting β2- agonists for one hour with an
interval of 20 minutes is possible.
• Anticholinergic drugs block the muscarinic cholino-receptors for
acetylcholine. Bronchodilator effect of Ipratropii bromidum (Atrovent)
develops through 15-20 minutes after inhalation.
• Through a spacer 2 doses (40 mg) of the drug are inhaled once, via a
nebulizer - 8-20 drops (100-250mkg) 3-4 times a day.
• In the complex treatment of BOS a combined preparation "Berodual" is
most commonly used; it combines two mechanisms of action: stimulation
of β2-adrenergic receptors and M-cholinergic receptors blockade.
• Berodual contains Ipratropii bromidum and Fenoterolum. The best way is a
nebulizer drug delivery.
• Single dose for children up to 5 years old is on average 1 drop / kg 3-4
times a day.
• Short-acting theophyllines are now usually referred
to the preparations of the second stage and are
administered at the lack of effectiveness of shortacting β2- agonists and M-anticholinergics.
• In severe obstruction eufillin 2.4% is prescribed dripfeed in saline solution in a daily dose of 16-18mg /
kg, divided into 4 injections.
Anti-inflammatory therapy
• For the treatment of severe BOS ICS (Dexamethasone and Budesonide
"Pulmicort") are used. Beginning with 6 months of age they are
administered by inhalation through a nebulizer in a daily dose of 0.25-1 mg
/ day (the amount of inhaled solution is adjusted to 2-4 ml by saline
solution). The drug is administered 2 to 4 times a day 15-20 minutes after
inhalation of bronchodilators.
• The duration of ICS therapy depends on the nature of the disease, duration
and severity of obstruction, as well as the effect of the therapy.
• In children with acute obstructive bronchitis with severe bronchial
obstruction, duration of treatment is usually 5-7 days, and in children with
croup - 2-3 days.
Algorithm of a severe course BOS therapy in children
1. Inhalation of short-acting β2-agonist through a
nebulizer, 1 dose every 20 minutes. for 1 hour.
2. IGC inhalation by nebulizer.
3. Inhalation of O2 to achieve SpO2 ≥ 95%.
4. Inhalation of mucolytics are contraindicated!!!
5. Abundant alkaline drink.
Good effect:
1. Inhalation of short-acting β2-agonist
through a nebulizer, 1 dose every 6-8
hours
2. Inhalation of nebulized
corticosteroids 1-2 times a day
3. Inhalation of mucolytics nebulized
4. Abundant alkaline drink
A good answer
Unsatisfactory effect:
1. Inhalation of short-acting β2-agonist
through a nebulizer, 1 dose every 6-8
hours
2. I/v introduction of methylxanthines
(2.4% solution of aminophylline)
3. I/v introduction of GCS
4. Infusion therapy
5. Oxygen therapy
An unsatisfactory answer:
•Transfer to the emergency
department
•ALV
Indications for hospitalization of children
with BOS, developed against ARVI
1. The ineffectiveness of the treatment at home for 1-3 hours.
2. The expressed severity of the patient's condition.
3. Children from high-risk groups.
4. By social reasons.
5. If it is necessary to determine the nature of BOS and selection
of therapy of asthma attacks occurred for the first time .
Conclusions
• 1. Bronchial obstruction syndrome in children is common and
takes a severe course, accompanied by signs of severe
respiratory failure.
• 2. It manifests, as a rule, against a background of acute
respiratory infection, BOS may be a manifestation of many
pathological states.
• 3. The prognosis of the BOS course is serious and depends on
the form of the disease that caused the bronchial obstruction,
and timely conducting of pathogenetic schemes of therapy and
prevention.
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House "Medpraktika-M", 2007.- pp 454-476.
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