1、,Respiratory System Disorders,1,Pediatric pulmonary diseases account for almost 50% of deaths in children under age 1 year and 20% of all hospitalization of children under age 15 years.,2,Bryce et al. WHO estimates of the causes of death in children. Lancet 2005,3,Respiratory tract infections repres

2、ent the most common infections of childhood and range from trivial to life threatening illness. Other diseases of this system include asthma, disorders of pleura or pleura cavity, lung tumor, congenital abnormality.,4,Anatomy and Physiology of Respiratory System,The knowledge of basic respiratory ph

3、ysiology and anatomy is one of the basic requirements for correct interpretation of symptoms and physical signs and in the attainment of an age appropriate differential diagnosis. There are a number of significant anatomic and physiological differences between children and adults that have impact on

4、 assessment and management. The child is not only physically smaller but also has immature respiratory systems with fewer reserves than those of the adult.,5,Normal anatomy Respiratory system is divided into upper respiratory tract and lower respiratory tract by cricoid cartilage. upper respiratory

5、tract: nose, nasal sinuses, pharynx, pharyngotympanic tube , epiglottis , larynx lower respiratory tract: trachea, bronchus, bronchiole , respiratory brochiole, alveolar ductules , alveolus,6,Nasal passage is shorter, no vibrissa , mucosa has a rich vascularity-liable to infection Nasal passage is n

6、arrow-liable to obstruction, resulted dyspnea. Nasal sinus ostia is large-nasosinusitis. pharyngotympanic tube is broader, straighter, shorter and horizontal-otitis media . pharyngeal tonsils :start to enlarge at the end of 1 year, peak at 4 to 10 year-old, degeneration at 1415 years old-tonsillitis

7、 rarely occurs in infants. Larynx is in a shape of funnel and narrow, cartilage is flexible, mucosa is tender and rich of vessel-laryngeal edema and narrow,7,Trachea and bronchus are narrower than those of adult; cartilage is flexible, lack of elasticity tissue, supporting action is weak Airway wall

8、 account for 30% of Airway wall area in children, 15% in adult. mucosa is tender and rich of vessel. The right main bronchus is more vertical and broader than the left and it offers an easier passage for aspirated foreign bodiers. Bronchiole has not cartilage- easy to collapse, result to retention o

9、f gas and effect the exchange of gas. The amount and size of alveolus is less and small. Chest is shorter and in a barrel shape, has a smaller scope of activities,8,The airway are lined with an epithelial membrane that gradually changes from ciliated pseudostratified columnar epithelium in the bronc

10、hi to a ciliated cuboidal epithelium near the gas-exchanging units. The three lobes (upper, middle and lower) of right lung has separated by the horizontal and oblique fissures, respectively.,9,The left lung has two major lobes (upper and lower) separated by an oblique fissure, and the upper lobe is

11、 itself divided into upper and lingular lobes. The right lung and the left lung project low down behind the dome of the diaphragm and peak behind the clavicles.,10,Normal physiology The principal function of the lung is to carry through gas exchange, which is to enrich the blood with oxygen and clea

12、nse it of carbon dioxide. An essential feature of normal gas exchange is that the volume and distribution of ventilation are appropriate.,11,The extrathoracic components of the respiratory tree trend to collapse inwards during inspiration and open during expiration. Therefore, if the extrathoracic a

13、irway is obstructed, the obstruction is first evident during inspiration and, as the airway further narrows, obstruction occurs during both phases of breathing.,12,By the action of respiratory muscles the intrathoracic airways are actively opened during inspiration. In addition, surfactant reduces t

14、he surface tension of the alveoli, thereby reducing the effort to keep the alveoli open during inspiration. During expiration, the airways tend to collapse because of the natural elasticity of the lung. Therefore, partial obstruction of the intrathoracic airways causes earlier closure of the airways

15、 during expiration and results in air-trapping with eventual over inflation of the lung.,13,Acute upper respiratory tract infection,14,The upper respiratory tract comprises the nose, throat, tonsils, pharynx, and sinuses. Acute upper respiratory infection (also called common cold syndrome) is very c

16、ommon in all paediatric age groups. The nose and pharynx are the most common sites of infection.,15,Etiology,Viruses: respiratory syncytical virus, rhinovirus, adenovirus, parainfluenza virus, and influenza virus. Bacterial: streptococcus,16,Clinical manifestations,The commom cold :running nose, nas

17、al congestion, sore throat, lacrimation, cough, and sneezing, low grade fever vomiting, diarrhea, abdomen pains convulsion,17,Special types of AURI: 1)herpangian: cause by coxsackievirus fever, extreme irritability, poor appetite small blister , ulcers on the lips, gums and tongue.,18,2) pharyngo-co

18、njunctival fever: caused by adenovirus type 3 or type 7. fever, pharyngitis, conjunctivitis swollen lymph nodes/gland gastrointestinal symptoms,19,Complication,Otitis media Infectious laryngitis Peritonsillar abscess Pneumonia Post-streptococcal glomerulonephritis Rheumatic fever,20,Laboratory test,

19、Virus: white blood cell count is usually normal to low; virus isolation and serum test can confirm the agent. Bacteria: white blood cell count may increase. Pathogenic bacteria can also be cultured from pharyngeal swabs or throat washings. ASO titer is increased after streptococcus infection.,21,Dia

20、gnosis and differential diagnosis,Diagnosis is made by clinical manifestation. But the following may be considered for differential diagnosis: 1.Influenza: influenza infection is easiy recognized during epidemics. In older children produces a syndrome of sudden onset of high fever, severe myalgia, h

21、eadache, and chills. Parainfluenza virus or influenza virus could be found.,22,2. Earlier period of acue infectious disease: Epidemics, clinical manifestations, and laboratory findings may be arrived at the diagnosis. Pay attention to state of the illness.,23,3.Acute appendicitis: Abdominal pain may

22、 present before fever. Localization of pain to the hypogastric region. Abdominal muscle is tense with fixed tenderness. White blood cell counts may increase.,24,Treatment,General therapy: rest, ensure an adequate fluid intake, and prevent complication. Pathogenic therapy: Antivirus: Clinically used

23、anti-virus drugs include virazole (ribavirin), persantine and interferon. The drug could be used for 3 to 5 day. If it is caused by hemolytic streptococci, penicillin should be used for 10 to 14 days.,25,Symptomatic management: Fever is controlled by antipyretics, such as compound aminopyrine, and p

24、aracetamol. Alcohol sponging also is used. Some oral laryngopharynx drug could be given to control sore throat. Chinese herb: banlan gen, daqing ye and so on can antivirus and relieve toxicity symptom.,26,Acute Bronchitis,Acute bronchitis is an infection of he bronchial mucous membranes. It may be complication of acute upper respiratory infection, or clinical situation of acute infection disease. Because trachea is usually involved at the same time, so it is also defined as acute tacheobronchitis. This disorder appears to be more common in younger children.,27,Etiology bacteria Vi