Pediatric respiratory system anatomy, physiology, immune characteristics, and examination methods
anatomical features
Upper respiratory tract (nose, sinuses, nasolacrimal/Eustachian tube, pharynx, larynx)
Nose (susceptible to infection) → short nasal cavity and rich mucosal blood vessels
Pharynx
Palatal tonsils reach their peak between 4 and 10 years old
Pharyngeal tonsils develop at 6 months → can cause sleep apnea in children
Lower respiratory tract (trachea, bronchi, lungs)
tracheobronchi
shorter and narrower than adults
Insufficient mucus glands → drier airways
The left main bronchus is long and slender, and the right main bronchus is short and thick.
Bronchiolar smooth muscle does not develop until 3 years old after birth → respiratory tract obstruction in young infants → mainly mucosal swelling and secretion obstruction
lung
Poor elastic tissue development
Well developed mesenchyme
Physiological characteristics (mainly abdominal breathing)
Acute upper respiratory tract infection (most common)
Cause (mainly virus → rhinovirus, respiratory syncytial virus)
clinical manifestations
Common types of acute upper respiratory tract infection
symptom
Local symptoms (more common in older children) → nasal congestion, runny nose, sneezing, dry cough
Systemic symptoms (more common in infants and young children)
Fever, irritability, general malaise and fatigue
Some have abdominal pain (paroxysmal pain around the umbilicus, no tenderness)
symptom
Swollen lymph nodes in the jaw and neck
Special types of acute upper respiratory tract infections
herpangina
The pathogen is →Coxsackievirus group A
★peeing
Good hair in summer and autumn
High fever, sore throat, anorexia and vomiting
White herpes can be seen on the pharyngeal mucosa with redness around it (herpes congestion)
Pharyngeal conjunctival fever
Adenovirus type 3 7
★Pickled pickles
Fever Pharyngitis Conjunctivitis
Good hair in spring and summer
High fever, sore throat, eye irritation, digestive tract symptoms
Congestion and white peelable discharge from the pharynx
Unilateral/bilateral follicular conjunctivitis Bulbar conjunctival hemorrhage
acute infectious laryngitis
Cause
Common viruses are→parainfluenza virus, influenza virus, adenovirus
Common bacteria are → Staphylococcus aureus Streptococcus
clinical manifestations
Acute onset and severe symptoms
Serious symptoms include
laryngeal obstruction
First degree (difficulty breathing after activity) (respiration and heart rate normal)
Second degree (dyspnea at rest) (with tubular breath sounds)
Third degree (irritability, eyes wide open in fear → due to hypoxia)
Fourth degree (drowsy state)
Acute bronchitis (infection of bronchial mucosa caused by pathogens)
clinical manifestations
First there is upper respiratory tract infection → then cough is the main problem (first dry cough → then phlegm)
Severe symptoms in infants and young children
Rough breath sounds in both lungs → irregular scattered dry rales and moist rales
Differentiation (acute bronchitis → irregular scattered rales) → bronchitis in the bronchi. The bronchial caliber is large, sputum will slide, and moist rales are not fixed (acute bronchopneumonia → fixed rales) → bronchopneumonia in the bronchi and lungs. The sputum will be fixed in the lobes of the lungs, and there will be fixed localized crackles.
Bronchiolitis (asthmatic pneumonia) (respiratory syncytial virus)
Cause
Mainly caused by respiratory syncyst virus
pathology
Invasion of bronchioles → epithelial cell necrosis, lymphatic infiltration → mucosal edema → bronchiolar lumen stenosis → emphysema
clinical manifestations
Main manifestations: wheezing, wheezing in the lungs, lower respiratory tract obstruction, fever
Symptoms of lower respiratory tract obstruction
Symptoms of systemic poisoning are mild, less high fever
Physical examination
Shallow and fast breathing, flaring nose, three concave signs
Voicelessness during percussion
Auxiliary inspection
Chest x-ray
Thickening of lung texture
identify
★Bronchial asthma without fever → mostly caused by allergies
Bronchiolitis has fever → is caused by viral infection
treat
Anti-infective treatment
★Erythromycin is ineffective → because it is a viral infection
Bronchial Asthma
Pathogenesis
Essentially: Chronic inflammation of the airways
Pathophysiology
Bronchospasm → immediate asthma (IgE mediator release, mast cells release histamine)
Inflammatory swelling of the tube wall → delayed asthma (reduced airway diameter occurs 6-24 hours after antigen stimulates the airway)
Mucus plug formation → delayed onset asthma
Airway remodeling → caused by chronic and recurrent inflammatory damage
⭐Airway hyperresponsiveness→Basic characteristics of asthma (airways are highly sensitive to irritating factors)
clinical manifestations
Paroxysmal coughing and wheezing (worst at night and early morning)
Before the attack → runny nose, sneezing and chest tightness
During attack
Prolonged expiratory phase
Physical examination
Lungs filled with expiratory wheeze
In serious cases → extensive airway obstruction → wheezing disappears → atretic lung (critical manifestation)
Auxiliary inspection
Children with forced expiratory volume in first second (FEV1) ≥70% of normal predicted value
diagnosis
Diagnostic criteria for childhood asthma
★Infectious factors, mainly wheezing and wheezing
Repeated wheezing and coughing, shortness of breath and chest tightness
physical and chemical stimulation
respiratory tract infection
There may be scattered/diffuse wheezing → mainly expiratory phase wheezing in both lungs
Effective/spontaneous relief after anti-asthmatic treatment
Positive bronchodilation test
Inhaled beta2 agonist (albuterol) → FEV1 (forced expiratory volume in first second) increases by 12% after 15 seconds
Anti-inflammatory treatment improves bronchial ventilation function
Administration of inhaled corticosteroids → FEV1 increased by 12%
PEF (day variation rate) ≥ 13%
cough variant asthma
★No infectious factors, mainly coughing and waking up attacks
Cough > 4 weeks (exercise/attack in the early morning) (or wake up with cough in the early morning) → mainly severe cough symptoms
No signs of infection, antibiotic treatment is ineffective (erythromycin)
Bronchodilators are effective → cough relief after inhalation
installment
Acute attack of asthma (sudden wheezing, coughing and chest tightness)
Chronic duration (symptoms appear to varying degrees in the past three months)
treat
Acute attack of asthma (mild)
Preferred β2 agonist→albuterol terbutaline
Status asthmaticus (severe)
Systemic glucocorticoids→hydrocortisone
Treatment of chronic asthma
Inhaled corticosteroid → budesonide
pneumonia
Classification of pneumonia
Pathological classification
Bronchopneumonia (lobular pneumonia)
Brief description
Involvement of bronchial wall
Lobular pneumonia is more common in children
According to the classification of etiology and pathological causes
Lung tissue congestion, edema, inflammatory cell infiltration
Inflammation of small bronchi and capillaries → partial or complete obstruction of the lumen → emphysema/atelectasis
bacterial pneumonia
Mainly damaged lung parenchyma
viral pneumonia
Mainly interstitial damage
Pathophysiology
Bronchial/alveolar inflammation → ventilation impairment → hypoxia and carbon dioxide retention (key to system changes)
Pathogen
Bronchial mucosal congestion and edema → lumen stenosis and occlusion → emphysema and atelectasis → ventilatory dysfunction
Alveolar wall congestion and edema → filled with viscous exudate → ventilatory dysfunction
Specific performance
Respiratory insufficiency
Electrolyte imbalance→hypoxia→increased anaerobic glycolysis→increased acid metabolism→acid substitution→at the same time, the elimination of carbon dioxide is blocked→produces acid respiration→therefore, severe mixed acidosis may occur
cardiovascular system changes
Changes in gastrointestinal function
clinical manifestations
physical signs
Pulmonary rales (fixed moist rales)
There are scattered small and medium bubbly sounds
Severe pneumonia
Cardiovascular System
Breathing and heart rate suddenly increase in quiet state
Sudden paleness and cyanosis
Low heart sounds, galloping rhythm
nervous system
Irritability, coma, convulsions, altered light reflex, meningeal irritation
digestive system
severe abdominal bloating
Insufficient antidiuretic hormone syndrome
Auxiliary inspection
Chest x-ray
Early lung markings are enhanced and light transmittance is reduced
Dot-like/patchy shadows appear in the lower fields of both lungs
Complications
Complicated pyopneumothorax
Fluid level on the affected side
Complicated pulmonary bullae
Complete thin-walled aneroid bulla
diagnosis
Fever, cough, shortness of breath, fine moist rales during lung auscultation
viral pneumonia
★Antibiotics are ineffective
respiratory syncytial virus
More common in infants and young children
interstitial inflammation
x-ray
Small spots and flakes in both lungs
Adenovirus pneumonia
clinical manifestations
Persistent fever (residual fever)
accompanied by breathlessness
signs of pulmonary consolidation
Predisposed to myocarditis and organ failure
X-ray image→large shadow and large lesion
Diagnosis → persistent high fever and frequent cough
bacterial pneumonia
Streptococcus pneumoniae pneumonia
Staphylococcus aureus pneumonia
Fever is mostly flaccid fever
May be accompanied by pyopneumothorax, empyema
Pneumothorax→Percussion sounds, breath sounds disappear
Pyopneumothorax → drum sound above the lungs and solid sound below the lungs
treat
Puncture and drainage of pus
If ineffective→thoracic closed drainage
Other microbial pneumonia
Mycoplasma pneumoniae pneumonia
clinical manifestations
Paroxysmal dry cough irritating cough
Imaging characteristics of respiratory diseases
Adenovirus pneumonia
Flake shadows of varying sizes or fused into large lesions
respiratory syncytial virus
Pathogen
respiratory syncytial virus
Note: Lobar pneumonia → adults are susceptible
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