1、,Respiratory System Disorders,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.,Bryce et al. WHO estimates of the causes of death in children. Lancet 2005,Respiratory tract infections represent th
2、e 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.,Anatomy and Physiology of Respiratory System,The knowledge of basic respiratory physiology
3、 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 assessm
4、ent and management. The child is not only physically smaller but also has immature respiratory systems with fewer reserves than those of the adult.,Normal anatomyRespiratory system is divided into upper respiratory tract and lower respiratory tract by cricoid cartilage. upper respiratory tract: nose
5、, nasal sinuses, pharynx, pharyngotympanic tube , epiglottis , larynx lower respiratory tract: trachea, bronchus, bronchiole , respiratory brochiole, alveolar ductules , alveolus,Nasal passage is shorter, no vibrissa , mucosa has a rich vascularity-liable to infection Nasal passage is narrow-liable
6、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 rarely occur
7、s 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,Trachea and bronchus are narrower than those of adult; cartilage is flexible, lack of elasticity tissue, supporting action is weak Airway wall account for 30
8、% 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 of gas and effec
9、t 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,The airway are lined with an epithelial membrane that gradually changes from ciliated pseudostratified columnar epithelium in the bronchi to a ciliated
10、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.,The left lung has two major lobes (upper and lower) separated by an oblique fissure, and the upper lobe is itself divided int
11、o 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.,Normal physiology The principal function of the lung is to carry through gas exchange, which is to enrich the blood with oxygen and cleanse it of carbon dioxi
12、de. An essential feature of normal gas exchange is that the volume and distribution of ventilation are appropriate.,The extrathoracic components of the respiratory tree trend to collapse inwards during inspiration and open during expiration. Therefore, if the extrathoracic airway is obstructed, the
13、obstruction is first evident during inspiration and, as the airway further narrows, obstruction occurs during both phases of breathing.,By the action of respiratory muscles the intrathoracic airways are actively opened during inspiration. In addition, surfactant reduces the surface tension of the al
14、veoli, 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 during expiration and resul
15、ts in air-trapping with eventual over inflation of the lung.,Acute upper respiratory tract infection,The upper respiratory tract comprises the nose, throat, tonsils, pharynx, and sinuses. Acute upper respiratory infection (also called common cold syndrome) is very common in all paediatric age groups
16、. The nose and pharynx are the most common sites of infection.,Etiology,Viruses: respiratory syncytical virus, rhinovirus, adenovirus, parainfluenza virus, and influenza virus. Bacterial: streptococcus,Clinical manifestations,The commom cold :running nose, nasal congestion, sore throat, lacrimation,
17、 cough, and sneezing,low grade fevervomiting, diarrhea, abdomen painsconvulsion,Special types of AURI: 1)herpangian: cause by coxsackievirusfever, extreme irritability, poor appetitesmall blister , ulcers on the lips, gums and tongue.,2) pharyngo-conjunctival fever: caused by adenovirus type 3 or ty
18、pe 7.fever, pharyngitis, conjunctivitisswollen lymph nodes/glandgastrointestinal symptoms,Complication,Otitis media Infectious laryngitis Peritonsillar abscess Pneumonia Post-streptococcal glomerulonephritis Rheumatic fever,Laboratory test,Virus: white blood cell count is usually normal to low; viru
19、s 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.,Diagnosis and differential diagnosis,Diagnosis is made by clinical
20、 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, headache, and chills. Parainfluenza virus or influenza virus cou
21、ld be found.,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.,3.Acute appendicitis: Abdominal pain may present before fever. Localization of pain to the hypogastric region.
22、 Abdominal muscle is tense with fixed tenderness. White blood cell counts may increase.,Treatment,General therapy: rest, ensure an adequate fluid intake, and prevent complication. Pathogenic therapy: Antivirus: Clinically used anti-virus drugs include virazole (ribavirin), persantine and interferon.
23、 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.,Symptomatic management: Fever is controlled by antipyretics, such as compound aminopyrine, and paracetamol. Alcohol sponging also is used. Some oral laryngopharynx drug cou
24、ld be given to control sore throat. Chinese herb: banlan gen, daqing ye and so on can antivirus and relieve toxicity symptom.,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 acut
25、e 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.,Etiologybacteria VirusRhinitis, sinusitis, rickets, malnutrition can promote the illness progress.,Clinical manifes
26、tationscoughsputum production, vomiting, malaise, fever, diarrhea.dyspnea and cyanosis are rare. Infant: tachypnea, recession, apnea.physical sign: intermittent cyanosis, crepitation, wheeze, dehydration, hepatomegaly,Asthmatic bronchitis: (1) most patients had suffer from eczema or other allergic i
27、llness before 3 years old. (2) symptoms like asthma. (3) repeated episode.,Chest X-ray Normal Lung markings thicken Hyperinflation,Treatment 1.gerneral therapy: rest, inhalation oxygen and adequate hydration 2.control infection anti-virus therapy or antibiotics. 3.symptomatic management: control cough, dilute sputum; control asthma, aminophylline, bricanyl, inhaled steroids, B2-adrenoceptor agonists. prednisone,
