急性上呼吸道感染英文課件

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 2005Respiratory tract infections represent the

2、 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 SystemThe knowledge of basic respiratory physiology an

3、d 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 assessment

4、 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, nas

5、al 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 infectionNasal passage is narrow-liable to obs

6、truction, 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 occurs in infa

7、nts.Larynx is in a shape of funnel and narrow, cartilage is flexible, mucosa is tender and rich of vessel-laryngeal edema and narrowTrachea and bronchus are narrower than those of adult; cartilage is flexible, lack of elasticity tissue, supporting action is weakAirway wall account for 30% of Airway

8、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 effect the exchang

9、e 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 cuboidal epithe

10、lium 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 into upper and ling

11、ular lobes. The right lung and the left lung project low down behind the dome of the diaphragm and peak behind the clavicles.Normal physiologyThe principal function of the lung is to carry through gas exchange, which is to enrich the blood with oxygen and cleanse it of carbon dioxide. An essential f

12、eature 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 obstruction is firs

13、t 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 alveoli, thereby redu

14、cing 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 results in air-trapping

15、with eventual over inflation of the lung.Acute upper respiratory tract infectionThe 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. The nose and pharyn

16、x are the most common sites of infection.EtiologyViruses: respiratory syncytical virus, rhinovirus, adenovirus, parainfluenza virus, and influenza virus.Bacterial: streptococcusClinical manifestationsThe commom cold :running nose, nasal congestion, sore throat, lacrimation, cough, and sneezing, low

17、grade fever vomiting, diarrhea, abdomen pains convulsion Special types of AURI:1)herpangian: cause by coxsackievirus fever, extreme irritability, poor appetite small blister , ulcers on the lips, gums and tongue. 2) pharyngo-conjunctival fever: caused by adenovirus type 3 or type 7. fever, pharyngit

18、is, conjunctivitis swollen lymph nodes/gland gastrointestinal symptomsComplicationOtitis mediaInfectious laryngitisPeritonsillar abscessPneumonia Post-streptococcal glomerulonephritisRheumatic feverLaboratory testVirus: white blood cell count is usually normal to low; virus isolation and serum test

19、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 diagnosisDiagnosis is made by clinical manifestation. But the follow

20、ing 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 could be found.2. Earlier period o

21、f 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. Abdominal muscle is tense with

22、fixed tenderness. White blood cell counts may increase.TreatmentGeneral therapy: rest, ensure an adequate fluid intake, and prevent complication.Pathogenic therapy: Antivirus: Clinically used anti-virus drugs include virazole (ribavirin), persantine and interferon. The drug could be used for 3 to 5

23、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 could be given to control sore throat.C

24、hinese herb: banlan gen, daqing ye and so on can antivirus and relieve toxicity symptom.Acute BronchitisAcute 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.Etiol