Disease of the Respiratory system in Children ppt

Disease of the Respiratory
Disease of the Respiratory
system in Children
system in Children
ShangYunxiao
Department of Pediatrics , The
Second Clinical Hospital , China
Medical University ,
Introduction
Introduction
z The disease of respiratory system is one of
the most frequent reasons for hospitalization
of infants and children.
z Basic knowledge of the development and
functions of respiratory system are essential
to understand many of these respiratory
tract diseases.
1.
1.
Anatomical characteristics of
Anatomical characteristics of
respiratory system
respiratory system
z
z (1) The upper airway
z nose;
z paranasal sinuses;
z pharynx;
z Eustachian tube
z larynx
Nose

Nose
z Nose cavity→relatively short and small in
infant;
z The mucous membrane(mucosa) →tender
and soft, rich in vascularity;
z Infection occurs →swelling and congestion
of the mucous membrane → nasal
obstruction →dyspnea.
paranasal
paranasal
sinuses
sinuses
z Maxillary sinuses appear at 2yrs, develop
fully after 12yrs.
z Frontal sinuses appear at 2-3yrs, enlarge at
6yrs →Paranasal sinusitis rarely occurs in
infants.
pharynx;
pharynx;
z Relatively narrow and vertical, rich in
lymphoid tissue.
z Palatine tonsils begin to enlarge gradually at
the end of 1 yrs →develop at 4-10 yrs
→degenerated gradually after 14-15 yrs.
z Tonsillitis is often seen in elder children
than in infants.
Eustachian tube
Eustachian tube
z Broad, straight and short in infant;
z The position →horizontal;

z So when an infant catches cold, he may be
complicated with otitis media (tympanitis).
larynx
larynx
z Narrow in infants
z The mucous membrane is rich in vascularity.
z Congested and swollen in inflammation
→dyspnea.
(
(
2)
2)
The low airway
The low airway
z Trachea;
z bronchus;
z lungs;
Trachea and bronchus
Trachea and bronchus
z The lumen of trachea and bronchus
→relatively narrow;
z Mucosa →rich in vascularity;
z Cillium movement →poor;
z So easy to get infection →develop
obstruction.
z
z The right bronchus →direct continuation of
the trachea;
z The left bronchus spreads out from the
lateral surface of trachea;

z So foreign body →often aspirated into right
bronchus →atelectasis or emphysema of
right lung segment.
lungs
lungs
z Interstitial tissue↑
z Alveoli ↓
z Blood ↑
z Air ↓
z →easy to get inflammation →atelectasis.
(
(
3)
3)
Mediastinum
Mediastinum
and chest wall
and chest wall
z mediastinum →relatively larger in infant
than in adult.
z Surrounding tissue of mediastinum →loose
and elastic.
z If the pleural effusion or pneumothorax
occurs →mediastinal organs are easily
displaced.
z The chest wall →short and barrel-shaped
(barrel-shaped thorax or barrel chest)
z The position of diaphragm →high →small
chest cavity,while the lungs are relatively
large, the respiratory muscles are not well

developed →chest wall movement is
limited relatively and the expansion of
lungs are limited during respiration.
z When the respiratory tract disease occur,
exchange of gas →insufficient.
2.
2.
physiological characteristics
physiological characteristics
z (1) Frequency and rhythm of respiration
z The younger the child, the more rapid the
respiration is.
z The metabolism and oxygen requirement of
infants →high, but respiratory volume is
limited →have to increase frequency of
respiration for metabolic requirement.
z When the child begins to stand up and walk
→the diaphram decline gradually to the
level of 5
th
intercostal space.
z (2) Type of respiration
z In infant → abdominal respiration.
z After the child stands up and walks →the
diaphragm moves downward →the chest
cavity →increased (above 2 yrs)
→abdominal-chest respiration appears.
z (3)Volume of tidal air
z 6 ml per kg when the respiration is
peaceful

3.
3.
The immune characteristics
The immune characteristics
z The principal antibody in respiratory tract →
z S-IgA
z S-IgA is produced by plasma cells in the
submucosa of airway →can neutralize certain
viruses and toxins, and help the lysis of bacteria.
z The serum levels of IgA remain low during early
childhood →infants and children are susceptible to
infection of respiratory tract.
Pneumonia
Pneumonia
z 1.Classification of pneumonia
z (1) According to pathological changes
z A: lobar pneumonia
z one or more lobes are involved.
z lobar pneumonia is often present in old
children.
z B: lobular pneumonia
(brochopneumonia):
z lobular pneumonia is the most common
pattern in infants and younger children.
z So it is the focal point in our study.
z C: Interstitial pneumonia :
z (2) According to etiologic agents
z A: virus pneumonia
z Caused by viruses such as respiratory
syncytial virus (RSV), adenovirus (ADV),

cytomegalovirus (CMV), parainfluenza
virus,et al.
z B: Bacterial pneumonia:
z Such as pneumococcal pneumonia,
staphylococcal aureus pneumonia,
colibacillus pneumonia .
z C: Mycoplasma pneumonia .
z D: Others: Fungous pneumonia, Rickettsial
pneumonia, et al.
z (3) According to clinical manifestation
z Mild pneumonia
z Severe pneumonia →heart failure,
respiratory failure, toxic encephalopathy,
toxic intestinal paralysis, DIC.
Bronchopneumonia
Bronchopneumonia
z 1.Etiology of bronchopneumonia
z The incidence of
z Bacterial↓
（pneumococcal,Staphylococcus,
strptococcus, colibacillus)
z Mycoplasma↑
z Viruses (RSV, ADV)
z
2.
2.
pathophysiology
pathophysiology
of bronchopneumonia
of bronchopneumonia

z Edema and accumulation of mucus
→bronchiolar obstruction
z Walls of alveoli →thicken
z Alveoli are filled with inflammatory
exudates
z →impairs the normal exchange of gases in
the lungs
z Diminished ventilation of the alveoli
→hypoxemia and carbon dioxide retention
→interfere normal metabolic process and
normal function of the chief organs.
(
(
1)
1)
Hypoxemia
Hypoxemia
z Normal gas exchange is impaired →PaO
2
and Sa O
2
↓
z Cyanosis will appear when
z Sa O
2
↓＜85％
z reduced Hb＞ Hb5g/dl
z flow rate is increased by increase
respiratory frequency and heart rate in order
to compensate the hypoxemia.

z The respiratory failure occurs when PaO
2
z ＜50mmHg and PaCO
2
＞50mmHg.