兒科學英文課件：07 肺炎

1、Respiratory DisordersTopics Respiratory disorders Respiratory infections PneumoniaTopics Respiratory disorders Respiratory infections Pneumonia 50% of consultation with general practitioners or acute illness in young children and a third of consultations in older children 25-30% of acute pediatric a

2、dmissions to hospital, some of which are life-threatening Acute respiratory tract infections form a major part of pediatric practice Asthma is the most common chronic illness of childhood Cystic fibrosis is the most common inherited disorder in Caucasians causing chronic diseaseRespiratory Disorders

3、Topics Respiratory disorders Respiratory infections PneumoniaRespiratory Infections The most frequent infections of childhood: 6-8/year Pathogens: viruses, bacterial, other pathogens Host and environmental factors Classification of respiratory infectionsClassification of Respiratory InfectionsAccord

4、ing to the level of the respiratory tree most involved: Upper respiratory tract infection Lower respiratory tract infectionCase -1Jack, age four months, is sent at home by his general practitioner because of two days of cough, rapid, laboured breathing and poor feeding. He was born at 27 weeks gesta

5、tion, birth weight 979g and was discharged home at three months of age. On examination he was a fever of 37.4C and a respiratory rate of 60 breaths/min. His chest is hyperinflated with marked intercoastal recession凹. On auscultation there are generalized fine crackles劈啪聲 and wheezes. QuestionDo you

6、have any comments or what do you conclude anything from this case?Case -1Jack, age four months, is sent at home by his general practitioner because of two days of cough, rapid, laboured breathing and poor feeding. He was born at 27 weeks gestation, birth weight 979g and was discharged home at three

7、months of age. On examination he was a fever of 37.4C and a respiratory rate of 60 breaths/min. His chest is hyperinflated with marked intercostal recession. On auscultation there are generalized fine crackles and wheezes. PneumoniaQuestionWhat is pneumonia? Pneumonia is an inflammation of the paren

8、chyma of the lungs.Typical manifestations: cough, fever, tachypnea（氣促）, cyanosis（紫紺）, rales（濕啰音）DefinitionQuestionHow about the prevalence of pneumonia? Pneumonia accounts for approximately 15% of all respiratory tract infections Worldwide, about 3 million children die each year from pneumonia, with

9、 the majority of these deaths occurring in developing countries Pneumonia remains the most common cause of morbidity in ChinaIncidenceThe Global burden of Childhood Diseases Mortality :Main causes U5(Professor and Chair, Department of International Health, Johns Hopkins Bloomberg School of Public He

10、alth, USA)Globally, more than 10 million children under five years of age die each year, usually due to: 19% Pneumonia18% Diarrhoea10% Neonatal sepsis/pneumonia 8% Malaria-preterm delivery asphyxia at birthQuestionHow to classify pneumonias clinically? Anatomy Pathogens Severity Duration Onset siteC

11、lassification Bronchopneumonia（支氣管肺炎） Lobar or Lobular Pneumonia （大葉性或節(jié) 段性肺炎） Interstitial Pneumonia（間質(zhì)性肺炎）Based on anatomy or X-ray manifestation Based on etiology Bacterial Pneumonia Viral Pneumonia Mycoplasma Pneumonia Chlamydia Pneumonia Acute Pneumonia Prolonged Pneumonia Chronic PneumoniaBased

12、 on the course of pneumonia Mild Pneumonia Severe PneumoniaBased on the severity of pneumonia Community Acquired Pneumonia (CAP) Hospital Acquired Pneumonia (HAP)Based on the onset site of pneumoniaCommon pathogens in community and hospital infectionCommunity-acquired infectionViruses Streptococcus

13、pneumoniae（肺炎鏈球菌）Haemophilus influenzae（流感嗜血桿菌）Mycoplasma pneumoniae（肺炎支原體）Chylamidia （衣原體）Staphyloccocus aureus（金黃色葡萄球菌）Hospital-acquired infectionGram-negative bacteriaPseudomonas aeruginosa（銅綠假單胞菌）Klebsiella pneumoniae（肺炎克雷伯菌）Escherichia coli（大腸桿菌）Streptococcus pneumoniaeStaphylococcus aureusAnae

14、robes（厭氧菌）Fungi（真菌）BronchopneumoniaQuestionWhy are children likely have bronchopneumonia? Characters of childhood airway anatomic structure and their respiratory physiology Immune function of childhood High risk factors: premature baby, underlying disordersQuestionWhat cause bronchopneumonia? Bacter

15、ia: Streptococcus pneumoniae, Haemophilus influenzae, Moraxellacatarrhalis（卡他莫拉菌），Staphyloccocus aureus Viruses: RSV, IV, ADV, MPV, et al. MycoplasmaCauses of Bronchopneumonia Bacteria: Streptococcus pneumoniae, Haemophilus influenzae, Moraxellacatarrhalis（卡他莫拉菌），Staphyloccocus aureus Viruses: RSV M

16、ycoplasmaCauses of BronchopneumoniaPathology of PneumoniaNormalPneumoniaInflammaory exudateInflammaory exudatePathology of PneumoniaQuestionWhat are the pathophysiology of pneumonia?PathogensURTIBronchitisPneumoniaInflammatory exudateObstruction of airwayGas exchange abnormalVentilation abnormalhypo

17、xemia(低氧血癥）hypercapnia（高碳酸血癥）toxinemia（毒血癥）tachypneacyanosisRales啰音fevercoughSevere PneumoniaRespiratory failure PO2 6.67 kPa PCO2 6.67 kPaToxic carditis and DICToxic encephalopathy（中毒性腦?。〥igestive system symptom abdomen distension bloody diarrheaDisturbances of fluid and electrolyte metabolic acido

18、sis respiratory acidosis hyponatremiaQuestionWhat are the signs and symptoms of pneumonia? The clinical signs and symptoms of pneumonia depend primarily on the age of the patient, the causative organism, and the severity of the diseaseFeverCoughCyanosisTachypeneaRalesAge rangeDefinition of “fast bre

19、athing”Up to 2 months60 breaths/minute 2-12 months50 breaths/minute 1-5 years 40 breaths/minuteAge-realted respiratory rates indicative of a lower respiraotry tract infection out breathing inWith inspiration, the side of the nostrils flares outwardsNasal Flaring（鼻扇）With inspiration, the lower chest

20、wall moves inLower Chest Wall Indrawing out breathing inFeverCoughCyanosisTachypeneaRales Classic findings of pneumonia that occur in adults and older children, such as fever,cough and rales, are often absent in infants and toddlers Generally present with nonspecific signs and symptoms including let

21、hargy, irritability, poor feeding, vomiting If it appear respiratory failure or other abnormality of other system-severe pneumonia. Important PointsSevere PneumoniaRespiratory failure PO2 6.67 kPa PCO2 6.67 kPaToxic carditis and DIC tachycardia pale ECG abnormalToxic encephalopathy irritability leth

22、argy vomiting seizureDigestive system symptom abdomen distension bloody diarrheaComplications Empyema（膿胸） Pyopneumothorax（膿氣胸） Pneumatocele （肺大皰） Lung abscesses （肺膿腫） Atelectasis（肺不張）Laboratory Examination White blood cell count and C-reaction protein Pathogens examination: 1) Sputum cultures 2) Blo

23、od cultures 3) Rapid screening tests for virus or bacterial Bronchoscopy Blood gas analysis: hypoxia and/or hypercapniaRadiograph Evaluation Typical X-ray manifestation of bronchopneumonia is patchy infiltrates bilaterally Complication: lung abscesses, empyema, pyopneumothorax, pneumatocele, atelect

24、asis CT Normal chest X-ray正常胸片支氣管肺炎Patchy infiltrates大葉性肺炎NormalConsolidation膿氣胸Normalpyopneumothorax肺膿腫Normallung abscesses肺大皰Normalpneumatocele 左側(cè)肺不張NormalatelectasisQuestionHow to diagnosis pneumonia clinically? According to the typical clinical manifestation of bronchopneumonia According to X-ra

25、y manifestation Pay attention to the atypical manifestation of infants Evaluate the severity of pneumonia Find the etiology of pneumoniaDifferential Diagnosis Bronchitis Foreign Body Aspiration Tuberculosis AsthmaQuestionHow is pneumonia treated? Management Supportive care Antimicrobials therapy Hos

26、pitalization in selected cases Supportive Care Respiratory care may range from oxygenation, bronchodilators for wheezing, humidification or mist, suctioning, and postural drainage, intubation and mechanical ventilation Hydration (sometimes intravenous) Control of fever: brufen, acetaminophen Managem

27、ent of complicationsAntimicrobial TherapyOrganismAntimicrobialS. pneumoniaePenicillin (if not resistant). third-generation cephalosporin e.g. cefotaximeceftriaxone (if resistant to penicillin)H. influenzaeAzithromycin or Amoxicillin (if not resistant)Beta lactamaseCefuroxime or third-generation ceph

28、alosporin (if beta lactamase and resistant)S. aureusMethicillin (if not resistant) Vancomycin (if MRSA-methicillin resistant S. aureus) if penicillin allergy: vancomycin, clindamycinChlamydiaAzithromycin (other macrolides e.g erythromycin); alternative, sulfa drugsMycoplasmaAzithromycin (other macro

29、lides); alternative, tetracycline (if older than 8 years)RSVRibavirin (optional)InfluenzaAmantadine (if severe)BacteriaAtypicalVirusesAge GroupBacterialViralEmpiric TherapyNeonate (0-28 days)Group B streptococcus, gram-negative enteric E. coli, Klebsiella, Listeria monocytogenes, S. aureus, other gr

30、am-positive)Cytomegalovirus Herpes simplexAmpicillin and aminoglycoside (gentamicin or tobramycin or amikacin, or third- generation cephalosporin). Note: Avoid ceftriaxone 2 to bilirubin Infants 3-16 weeks; afebrile pneumonia infancyChlamydia trachomatis Ureaplasma urealyticum CytomegalovirusPneumoc

31、ystis cariniiErythromycin SulfonamideInfants febrile or ill appearing age 1-3 monthsSame organisms as for neonate plus S. pneumoniae, H. influenzae, S. aureusNot applicableAntibiotic (nafcillin, oxacillin, or methacillin) Broad-spectrum cephalosporin (e.g., cefotaxime)Toddler or preschool ageS. pneu

32、moniae, H. influenzae M. pneumoniae, ChlamydiaRSV Parainfluenza Adenovirus InfluenzaAzithromycinAmoxacillin-clavulanate: not active against atypical organisms (Mycoplasma, Chlamydia) Organisms Causing Pneumonia and Empiric Therapy in Pediatric BacteriaAntibioticsDurationG+ coccusPenicillin ， 1st and

33、 2nd cephalosporin 710 daysG- bacillus2nd and 3rd cephalosporin12 weeks S. aureus Piperacillin Sodium ，Vancomycin 34 weeksM. pneumoniaeMacrolides 23 weeksQuestionHow about the clinical course of pneumonia ? With treatment, pneumonia caused by bacteria can usually be cured in 1 or 2 weeks Pneumonia c

34、aused by a virus often lasts longerClinical CourseSeveral Pneumonias Bronchiolitis is the most common serious respiratory infection of infancy Two to three per cent of all infants are admitted to hospital with the disease each year during annual winter epidemics Respiratory syncytial virus (RSV) is

35、the pathogen in 75-80% cases Clinical features: Age: 2-6 monthSeasonWheezingX-rayDuration: 7-10 daysBronchiolitisHyperinflation of the lungs with flattening of diaphragmInvestigations RSV can be identified rapidly using a fluorescent antibody test on nasopharyngeal secretions The chest X-ray shows h

36、yperinflation of the lungs due to small airways obstruction and air trapping Blood gas analysis, which is required in only the most severe cases, shows lowered arterial oxygen and raised CO2 tension Management Supportive. Humidified oxygen is delivered into a head-box Mist霧, antibiotics and steroids

37、 are not helpful Nebulised bronchodialators do not reduce the severity or duration of the illness The antiviral drug ribavirin only marginally shortens viral excretion and clinical symptoms, and should be considered only for infants with underlying cardiopulmonary disorders or immunodeficiency Fluid

38、s may need to be given by nasogastric tube or intravenously Mechanical ventilation is required in about 2% of infants admitted to hospital There are over 60 types of adenoviruses, which account for 2-10% of all respiratory illnesses Adenoviral infections are common early in life, it is especially co

39、mmon in less than 2 year-old Epidemic respiratory disease occurs in winter and spring High grade fever, severe symptoms of systemic poisoning, and multiple organ damage. Symptoms persist for 2-4 weeksChest X- rear show bilateral peribronchial and interstitial infiltratesAdenoviral pneumonia can be n

40、ecrotizing and cause permanent lung damage, especially bronchiectasisThere is no specific treatment Adenoviral PneumoniaStaphylococcus aureus Pneumonia S. aureus is an uncommon but important cause of pneumonia that can occur in any age group S. aureus is a rapidly progressive fulminant illness S. au

41、reus pneumonia easily occurs complications Blood cultures are positive in 20-30% of patients The pleural effusions should be drained by thoracentesis or, if large, by a chest tube Pneumatoceles are also common and are found in 45- 60% of patients with S. aureus pneumonia Methicillin or vancomycin sh

42、ould be administered for 3- 4weeksMycoplasma Pneumonia M pneumoniae is a common cause of symptomatic pneumonia in older children Endemic and epidemic infection can occur The incubation period is long (2-3weeks), and the onset of symptoms is slow Although the lung is the primary infection site, extra

43、pulmonary complications sometimes occurClinical Features Fever, cough, headache, and malaise are common symptoms as the illness evolves Rales are frequently present on chest examination, decreased breath sounds or dullness to percussion over the involved area may be presentLaboratory findings The to

44、tal and differential white blood cell counts are usually normal The cold hemagglutinin titier should be determined, because it may be elevated during the acute presentation. A titer of 1:64 or higher supports the diagnosisImaging Chest x-rays usually demonstrate intersititial or bronchopneumonic inf

45、iltrates, frequently in the middle or lower lobes. Pleural effusions are extremely uncommon.Complications Extrapulmonary involvement of the blood, CNS, skin, heart, or joints can occur Direct Coombs-positive autoimmune hemolytic anemia,Coagulation defects and thrombocytopenia can also occur A wide v

46、ariety of skin rashes including erythema multiforma and Stevens-Johnson syndromeTreatment Antibiotic therapy with erythromycin or Azithromycin for 7-10 days usually shortens the course of illness Supportive measures, including hydration, antipyretics, and bed rest, are helpfulChlamydial Pneumonia Pu

47、lmonary disease due to C trachomatis usually evolves gradually as the infection descends the respiratory tract Infants may appear quite well despite the presence of significant pulmonary illness Appropriate age: 2-12 weeks Inclusion conjunctivitis, eosinophilia, and elevated immunoglobulins can be s

48、een Clinical Features About 50% of patients with chlamydial pneumonia have active inclusion conjunctivitis or a history of it Rhinopharyngitis with nasal discharge or otitis media may have occurred or may by currently present Cough is usually present. It can have a staccato character and resemble th

49、e cough of pertussis The infant is usually tachypenic. Scattered inspiratory rales are commonly heard, but wheezes rarely Significant fever suggests a different or additional diagnosisLaboratory findings Although patients may frequently be hypoxemic, CO2 retention is not common Peripheral blood eosi

50、nphilia has been observed in about 75% of patients Serum immunloglobulins are usually abnormal. IgM is virtually always elevated, IgG is high in many, and IgA is less frequently abnormal C trachomatis can usually be identified in nasopharyngeal washings using fluorescent antibody or culture techniqu

51、esImaging Chest x-rays usually reveal diffuse interstitial and patchy alveolar infiltrates, peribronchial thickening, or focal consolidation. A small pleural reaction can be present. Despite the usual absence of wheezes, hyperexpansion is commonly present Treatment Erythromycin or sulfisoxazole ther

52、apy should be administered for 14 days Oxygen therapy may be required for prolonged periods in some patientsSummary Pneumonia in pediatric patients encompasses a wide spectrum of etiologies and illness from mild to severe and life threatening Therapy should include an antibiotic if a bacteria or aty

53、pical bacteria (chlamydia or mycoplasma) is suspected. No antibiotics are necessary for viral pneumonia Supportive therapy also includes fever control, maintenance of hydration and respiratory care Close follow-up is necessary in order to detect any secondary bacterial infection or the development o

54、f complicationsKey Issues Etiology of pneumonia Pathophysiology of pneumonia Clinical feature of pneumonia Diagnosis and differential diagnosis of pneumonia Management of pneumonia Several special pneumoniasCase -1Jack, age four months, is sent at home by his general practitioner because of two days

55、 of rapid, laboured breathing and poor feeding. He was born at 27 weeks gestation, birth weight 979g and was discharged home at three months of age. On examination he was a fever of 37.4C and a respiratory rate of 60 breaths/min. His chest is hyperinflated with marked intercoatal recession. On auscu

56、ltation there are generalized fine crackles and wheezes. Case -1Jack, age four months, is sent at home by his general practitioner because of two days of cough, rapid, laboured breathing and poor feeding. He was born at 27 weeks gestation, birth weight 979g and was discharged home at three months of

57、 age. On examination he was a fever of 37.4C and a respiratory rate of 60 breaths/min. His chest is hyperinflated with marked intercoatal recession. On auscultation there are generalized fine crackles and wheezes. Case -2History: A 9-week old female infant come to see doctor with a 3 week history of

58、 rhinorrhea and a 2 week history of cough. The cough is described as explosive and occurring in clusters and it persists as a major clinical symptom. On one occasion, the baby could not seem to catch her breath. She has not had any fever. No one else in this family is ill. At 6 weeks of age, the infant rec