Disease of the Respiratory system in Children ppt

z The disease of respiratory system is one of the most frequent reasons for hospitalization of infants and children.. z The chest wall →short and barrel-shaped barrel-shaped thorax or b

Disease of the Respiratory

system in Children

ShangYunxiao Department of Pediatrics , The

Second Clinical Hospital , China

Medical University ,

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.Anatomical characteristics of

respiratory systemz

z(1) The upper airway

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 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

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

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)

z Narrow in infants

z The mucous membrane is rich in vascularity.

z Congested and swollen in inflammation

→dyspnea

(2) The low airway

z Trachea;

z bronchus;

z lungs;

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

(3)Mediastinum 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.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 5th 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.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.

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 Severe pneumonia →heart failure,

respiratory failure, toxic encephalopathy,

toxic intestinal paralysis, DIC

z Mycoplasma↑

z Viruses (RSV, ADV)

z

2.pathophysiology 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

z flow rate is increased by increase

respiratory frequency and heart rate in order

to compensate the hypoxemia

z The respiratory failure occurs when PaO2

z ＜50mmHg and PaCO2 ＞50mmHg

(2)acid and basic disorder

z PaO2 ↓ →O2 metabolism interruption

→acid metabolic ↑

z →metabolic acidosis

z PaCO2 ↑(retention of CO2)

z →respiratory acidosis

(3)cardiovascular system

z PaCO2 ↑and PaO2 ↓ →reflectory

contraction of pulmonary artery

→pulmonary hypertension

z Toxemia →toxic myocarditis.

z The pulmonary hypertension and toxic

myocarditis →heart failure

(4)Nervous system

z Retention of CO2 and hypoxemia →increase

of capillary permeability →cerebral edema

→central respiratory failure

z PaO2↓ →acid metabolic products ↑

→ATP ↓ → cerebral edema

z Toxemia →toxic encephalopathy

(5)Digestive system

z Hypoxemia and toxemia→toxic intestinal

paralysis →hemorrhage of gastrointestinal tract

3.Clinic manifestation

z Fever

z Cough dry cough →wet cough

z Dyspnea cyanosis →face, finger nails.

z respiratory distress

z grunting, flaring of nares, retractions

z Retractions (supraclavicular, intercostal,

and subcostal areas)

z tachypnea and tachycardia

Severe pneumonia

z A: Congestive heart failure

z B: Toxic encephalopathy

z C:Toxic intestinal paralysis

z D:Disseminated intravascular coagulation

A: Congestive heart failure

z a Restlessness, dyspnea becomes more

severe suddenly, paleness or cyanosis

z b Heart rate ＞180 /min (infants); ＞160

/min (children); heart sounds becoms low and dull

z c Liver enlarge ＞2cm in a short time.

z d Edema of face and feet may be

seen.Oliguria or anuria (some patients)

B Toxic encephalopathy

z a irritability, restless, lethargy

z b convulsion, coma, irregular respiration

and apnea (in severe case)

C:Toxic intestinal paralysis

z a Abdominal distension

z b peristaltic sound disappear

z D:Disseminated intravascular

coagulation

z Bleeding tendency: bleeding at sites of vein

puncture, or scattered petechiae over the skin, or gastric-intestinal bleeding

z WBC may be normal when the pathogen

is bacterium if the patient is malnutrition or very severe condition

z B Etiologic agent isolated

z from the nasopharygeal secretions

z (deep coughing, tracheal suction, or

z pleural fluid obtained at thoracentesis).

z Blood culture →bacteria pneumonia.

z Serological test →specific antibody to

z A empyema:

z Purulent pleurisy is an accumulation of

pus in the pleural spaces

z Pathogen →staphylococci, pneumococci.

z Toxic symptom →respiratory difficulty,

limited respiratory movement, dullness to percussion, breath sounds and vocal

fremitus↓(over the effusion)

z The radiological findings→collection of

fluid in the costaphrenic angles

z Large collection of fluid →shift of trachea

and mediastinal structure

z Thoracentesis should be performed when

empyema is suspected, and it is a good

procedure for diagnosis and treatment

B Pyopneumothorax or tension pneumothorax

z When the small abcess around the lung

breaks, air leaks into thoracic cavity

z Symptom →severe dyspnea and cyanosis

suddenly;

z percussion →hyperresonance

z auscultation →breath sound↓

z X-ray→air and fluid level

z When tension pneumothorax appears, the

thoracentesis and thoracic drain are required

z A symptoms →fever, cough and dyspnea

z B.Signs→moist rales in the lung

z C.Chest X-ray →spotted-like or patchy

shadows over the lung field

z D.Severe case → Congestive heart failure, Toxic encephalopathy,Toxic intestinal

paralysis, DIC

z E.Complications →empyema,

pyopneumothorax and pneumatocele

7.Differential diagnosis

z A Acute bronchitis:

z symptoms →mild

z breath sound →coarse,or a few

rales(sputum) at the end of inspiration and early expiration

z Chest X-ray →lung markings↑,

z no spotted or patchy shadows .

z

z B Bronchial foreign body:

z history → foreign bodies aspiration

z physical signs → bronchial obstruction,

z sudden onset of cough and wheezing.

z complete obstruction → atelectasis

z incomplete obstruction → emphysema

z C Pulmonary tuberculosis:

z Toxic symptom of TB → fever,

diminished appetite, weigh loss, irritability, malaise, easy fatigability, night sweating

z Positive tuberculin test

z history of recent contact with TB

8.The characteristics of different types of pneumonia

z A Staphylococcal aureus pneumonia:

z Pneumonia caused by Staph aureu is a

serious and rapidly progressive infection, unless recognized early and treatment

appropriately, the mortality is very high

z Pathologic changes → extensive areas of hemorrhagic necrosis

z Clinical manifestations → abrupt onset with fever, cough and evidence of respiratory

distress The sighs include

tachypnea,grunting respiration, three

retractions, cyanosis and restless

z Convulsion and shock-like state may be

present

z Some infants may be associated with

vomiting, diarrhea and abdominal distention

z Signs → diminished breath sounds and

z scattered rales are commonly

z heard over the affected lung

z Complications appear easily → lung

abscess, empyema, pyopneumothorax,pneumatocele

z

z WBC increase in peripheral blood with

increased neutrophils

z X-ray fidings →small patches of shadows

z small abscess.

z Pleural effusion or empyema is noted

during the course in the most patients

z Sputum or blood culture → Staph.aureu

z B.Adenovirus pneumonia

z It occus during the first 2 years of life,

with a peak incidence at approximate 6 months of age The illness usually occurs epidemically

z Pathologic lesion →bronchiolar

z obstruction and interstitial lesion

z Clinical manifestations →sudden onset with

z higher fever, usually continuous for one

z week, in severe case, the fever lasts for

z 2-3weeks.

z Respiratory distress →wheezy cough,

z dyspnea, pale, restless and cyanosis.

z Sighs →fine rales may be heard a few day

z later.

z Hypoxemia (diminished ventilation of

z Carbon dioxide retention

z Respiratory acidosis

z In severe cases →toxic encephalopathy,

z congestive heart failur

z WBC →usually normal

z X-ray →small patch or perifocal emphysema.

z Igm-ADV →positive

z C.Respiratory syncytial virus pneumonia

z It occurs during the first 2 years of life

z with a peak incidence within 6 months of

z age.

z Symptoms and signs →expiratory

z dyspnea, prolonged expiratory time

z expiratory grunting, pallor, restlessness,

z cyanosis and moderate fever.

z Auscultation →expiratory wheezes

z inspiratory moist rales.

z Percussion → hyperresonance sound.

z The liver seems enlarged owing to

z downward displacement of the right

z diaphragm or to congestive heart failure.

z In severe case →hypoxemia

z respiratory acidosis

z respiratory failure

z congestive heart failure

z WBC →usually normal

z X-ray →emphysema

z increased lung marking.

z IgM-RSV →positive

z D Mycoplasma pneumoniae

z pneumonia(MPP)

z mycoplasma(MP) can cause both upper

z and lower respiratory tract illness →

z bronchiolitis, pneumonia, bronchitis,

z tonsilitis and otitis media.

z MPP usually occurs in elder

children(5-15yeares), and in the climate of autumn and winter

z The incubation period →1-3weeks →may have headache, malaise, cough, fever, sore throat and muscular pain, or chest pain, loss

of appetite, nausea, vomiting and diarrhea

z Auscultation →a few dry or moist rales

z breth sound ↓(pleural

z WBC →normal or slightly high.

z Serum cold agglutination test →postive

z (highest titer at 2-4weeks)

z Specific antibody to MP (IgM-MP )

z X-ray →characterized by cloudy infiltration

z both lower lungs.The shadow sometimes

z wandering (the infiltration disappear in one

z lung and reappear in another lung) →

z lobar, lobular, interstitial changes.

(1) General treatment

z A Keep the ventilation well, relieving

hypoxia and CO 2 retention.

z when the secretion in airway is thick

→intermittent ultrasonic inhalant therapy is recommended

z B Oxygen therapy

z oxygen inhalation can be administrated

z with nasal cannula, the flow is

z 0.5-1L/min.

z If the hypoxia continues →Oxyhood

z may be used with a flow of 2-4L/min

z when respiratory failure occurs →

z ventilator is needed.

z The selection of antibiotics depends on →

z the degree of illness and the kinds of

bacteria.(the best way →give the most

sensitive antibiotic to the bacteria by

medicine sensitive test)

z intramuscular antibiotics →mild cases;

z intravenous antibiotics →severe cases

z Pneumococcal pneumonia →penicillin

z 300,000-600,000u /kg.d Bid iv.

z Staphylococcal aureus pneumonia

z Virus pneumonia →

z Virazole,10-15mg /kg.d qd iv.

z Interferons, 20000u, qd im (injection

z intramuscularity), for 3 days.

z Chinese traditional medicine

z Mycoplasma pneumoniae pneumonia →

z erythromycin 20-30mg /kg.d qd iv

z The principle of discontinue antibiotics:

z The signs of lungs have disappeared for 3 days,

no fever and cough.

z Mycoplasma pneumoniae pneumonia →

z usually 2-3weeks or longer.

z Staphylococcal aureus pneumonia →shoud be treated with a long course , the antibiotics should

be used for another 2 weeks if the signs of lungs have disappeared and no fever

z

z

z B.Control of heart failure:

z The following cardiotonnic drug is used:

z a Strophanthin K , 0.007-0.01mg /kg, iv.

z b Cedilanid

z total digitalizing dose 0.03-0.04 mg /kg,

z half od the total dose is used initially;

z after 6 hour,1 /4 of total dose is used

z again; the final 1 /4 of total dose is used

z another 6 hour later.

z The daily maintaining dose → 1 /4 of total dose.

z The way of administation may be im or iv.

z C Dehydration;

z Furosemide, 1mg /kg, im or iv;

z 20％Mannital 5ml /kg, q12h iv (used in

toxic encephalopathy)

(5)Supportive treatment

z A Inhale clean air;

z B good and enough nutrition;

z C.Elevate resistance of the body

z ( Ig, plasma or blood )

Tuberculosis in children

z Tuberculosis (TB) is a chronic infectious

disease caused by tubercle bacillus

z Primary TB is the chief type in children.

z Many cases of TB continue to occur in our

country, so TB remains an important

clinical problem in China

z Infants and children are most frequently

infected by adult, usually close relative such

as the members of the household

z The mode of infection consists of three

routes:

(1)From respiratory tract:

z Inhale the droplets of sputum, expelled by

the infectious individual during his