Lower Respiratory Tract Infection PDF

pedia.Dr.TareqL3 Fatima Abd Al Bari LOWER RESPIROTARY TRACT INFECTION 1- pneumonia Pneumonia is an infection of the lung parenchyma ( the lower portion of respiratory tract consist...

pedia.Dr.TareqL3 Fatima Abd Al Bari LOWER RESPIROTARY TRACT INFECTION 1- pneumonia Pneumonia is an infection of the lung parenchyma ( the lower portion of respiratory tract consisting of the respiratory bronchiole ,alveolar ducts ,alveolar sacs and alveoli) is associated with consolidation of the alveolar space. TYPES OF PNEUMONIA 1. Infec ous pneumonia. 2. hydrocarbon pneumonia. 3. aspira on pneumonia. 4. radia on pneumonia. 5. lipoid pneumonia. ( pneumonitis is a general term for lung inflammation that may or may not be associated with consolidation ). 1 pedia.Dr.TareqL3 Fatima Abd Al Bari Infectious pneumonia 1- VIRAL PNEUMONIA. A virus is the most common cause of pneumonia in children and the RSV is the most common virus ,others include parainfluenza.adenovirus ,influenza virus. Clinical features :- The picture start with several days of rhinitis and cough followed by fever and more profound respiratory symptoms such as dyspnea and intercostals retraction. Diagnosis :- 1. laboratory finding include predominance of lymphocyte on complete blood picture 3. diffuse bilateral infiltra on on CXR. 2. Specific diagnosis can be done by rapid test for viral Ag and by culturing nasopharyngeal specimens. Treatment :- Usually supportive by antipyretic. Oxygen and fluid sometime needed. Specific treatment :- Ribavirin effective for RSV in sever pneumonia. Amantidine for influenza type A. 2 pedia.Dr.TareqL3 Fatima Abd Al Bari 2. BACTERIAL PNEUMONIA The common bacterial cause in children older than three months include pneumococal pneumonia and streptococcus group A flowed by staph aureas and H influenza. Clinical features :- ( 1 ).The clinical features in older children ( about 6 yrs and older) Is fairly classic present first with mild upper respiratory tract symptoms followed by abrupt onset of fever , tachypnea , chest pain and shacking chills. Physical examination often reveals lateralization chest signs such as decrease breath sound and crepitation on the affected side. tubular breath sound.dullness to percusion and egophony in localized region ( 2). younger children < 6 yrs , may present with non specific manifesta on including fever ,malaise ,gastrointestinal complaints , restlessness, apprehension and chills. Respiratory signs may be minimal and include tachypnea and grunting respiration. Signs of pneumonia also may be subtle in young infant with absence of crepitation and rhonchi. Sometime the clinical pictures of pneumonia differ according to causative M.O. H influenza ytpe b pneumonia often associated with bacteremia , meningitis and other sites of infections ( arthritis , pleural effusion ,cellulites ). Staph. Aureas if present in infant ( 70 % of staph.pneumonia in infant present in first year ) ,associated with acute ill infant with empyema ,pneumatoceles and respiratory failure and the infant may have skin lesions , scalp or previous hospitalization and mother with mastitis. Lower abdominal pain may be associated with lower lobe pneumonia. Infant between one and three months of ages often have afebrile pneumonia with typically is due to congenital or acquired agent such as Chlamydia trachomatis ,CMV, Or pneumocystis carinii or RSV. Pneumonia in immunocompromized patient may be due to P.carinii, gram –ve enteric Bacteria ,fungi or CMV. Patient with cystic fibrosis usually due to pseudomonas aeruginosa. 3 pedia.Dr.TareqL3 Fatima Abd Al Bari DIAGNOSIS OF PNEUMONIA 1- Defini ve diagnosis of pneumonia require iden fica on of the causative organism. 2- Sputum for culture ( not easily taken for children ). 3-Chest x-ray o en shows lower consolida on and pleural effusion or pneumopyothorax that complicate pneumonia. 4-WBC is elevated with predominance of neutrophil , 5-if M.pneumonia suspected -Cold agglu nin are present in peripheral blood film. 6-Blood culture is essen al for Ag detec on 7-M.tuberculosis may be diagnosed by tuberculin skin test and analysis of sputum or gastric aspirates. 8-Invasive procedures such as bronchoscopy and bronchial –alveolar lavage ,lung aspirate , lung pleural aspirate and lung biopsy done in the unusual clinical picture Or immune compromised host. 4 pedia.Dr.TareqL3 Fatima Abd Al Bari treatment The following general guidelines take in consideration : 1.age. 2.severity of illness. 3.presence of illness in the family. 4. previous hospitaliza on. 5. lab. Studies must be considered when an bio cs is chosen. ( 1). Children younger than 6 yrs with mild to moderate illness can be observed at home and given oral an bio cs such as amoxicillin ( 50 mg /kg /day ) or Ampicillin ( 100 mg / kg /day ) or erythromycin 50 mg/kg /day ) Children with more severe illness required hospitalization and intra venous Cfotaxime ( 100mg/kg /day) ,ceftriaxone ( 50-75mg /kg/day ) or ceftazidime ( 100mg/kg/day ) a er that according to culture. If streptococcus pneumonia susceptible the crystalline penicillin is drug of choice. ( 2). children more than 6 yrs with mild to moderate illness can be observed at home and given oral penicillin or if Mycoplasma pneumonia is likely (macrolides ) can be used such as erythromycin or new generation ( azithromycin and clarythromycin ) In severe cases hospitalization and I V third generation cephalosporin. Other supportive treatment : 1.severe dyspnea or cyanosis is indication for oxygen. 2. an pyre c may be needed. 3. adequate intake of fluid must be ensured. 4. good nursing and the infant posi on in the cot should be changed frequently and his head should be raised above his feet. 5. blood gas analysis in severe ill case should be done. 6. ventilatory support may be needed in seriously ill child. 7. Chest physical therapy may be need to clear the secre on and encourage cough. Indication of hospitalization in pneumonia 1-failure to response to oral an bio cs. 2-inability to take oral an bio cs because of vomi ng or poor compliance. 3-lobar consolida on in more than one lobe. 4-immune suppression. 5-moderate to severe respiratory distress. 6-empyema. 7-abscess or pneumatocele. 8-underling cardiopulmonary diseases. 5 pedia.Dr.TareqL3 Fatima Abd Al Bari 2-BRONCHIOLITIS A common disease of lower respiratory tract of infant results from inflammatory obstruction of small airways.. Respiratory syncytial virus ( RSV ) is the causa ve agent in more than 50% of cases.others may caused by para-influenza , mycoplasma or adenovirus or measles. There is no firm evidence that bacteria can cause bronchiolitis. Bronchioli s occur most commonly in male infant between 3-6 months ,who have not been breast –fed and who is living in crowded condition and have smoker mother. The source of viral illness is usually a family member with respiratory illness. Pathophysiology Acute bronchiolitis is characterized by bronchiolar obstruction due to edema and accumulation of mucus and cellular debris and by invasion of the smaller bronchial by virus ,and because the radius of airway is smaller during expiration the resultant ball valve respiratory obstruction leads to early air Trapping and over inflation. Atelactasis may occur when the obstruction becomes complete and trapped air is Absorbed. The pathologic process impairs the normal exchange of gasses in the lung. Ventilation – perfusion mismatched result in early hypoxemia. CLINICAL MANEFISTATION The infant first has a mild upper respiratory tract infection with serous nasal discharge and sneezing , these symptoms usually lasts few days and may be accompanied by diminished appe te and fever of 38 c.The gradual development of respiratory distress characterized by wheezy cough , dyspnea and irritability. In mild cases symptoms disappear in 3 days.In more severe cases may develop within several hours. On examination :- the patient in distress ( subcostal ,inter costal recession ).Palpable liver and spleen due to over inflated lung ,wide spread Fine crepitation may be heard. The expiratory phase of breathing is prolonged and rhonchi are Audible. Chest x-ray finding : 1. hyper infla on of the lung and increased antero –posterior diameter. 2. sca ered area of consolida on. 3. some mes increased translucency of the lungs DIFFERNTIAL DIAGNOSIS OF BRONCHIOLITIS : 1. Bronchial asthma that accompanied by repeated episodes with family history and respond well to bronchodilator. 2. foreign body usually the history of aspira on and localized sings on Examination. 3. Bacterial bronchopneumonia that associated with generalized obstructive pulmonary over inflation 4. heart failure , usually with cardiac murmur 6 pedia.Dr.TareqL3 Fatima Abd Al Bari Admission criteria : ( 1).any risk factors ( age < 3 months , previous severe bronchiolitis , premature Apnea , chronic lung disease, congenital heart diseases Immunodeficiency , multiple congenital abnormalities , Severe neurological diseases ,social concerns ). ( 2). moderate or severe bronchiolitis. PROGNOSIS :- The first three days usually most critical ,after that the improvement occur rapidly and the death may due to : apneic attach. respiratory failure. severe dehydration. associated some cardiac or immunity problems. A significant proportion of infant have hyper reactive airways during later Childhood. TREATMENT OF BRONCHIOLITIS 1.Hospitaliza on of infant with respiratory distress. 2.cool place and humidified oxygen to relieve hypoxemia and reduce water loss from tachypnea. 3.avoidance of seda on to irritable infant. 4.si ng the infant in 40 degree angle and the head and chest slightly elevated to extend the neck. 5. intra venous fluid to replace the loss. 6. ribavirin , antiviral given by aerosol for immune deficient patients or with cardiac diseases 7. an bio cs to treat or prevent bacterial invasion. 8. steroid may be used but some me may be harmful. 9. bronchodilators are frequently used. 10. those pa ents with impending respiratory failure requiring ventilatory help. 11. as preven on RSV immune globulin may be given to risky cases. Discharge if all of the following are confirmed : 1. feeding well 2. no cyanosis in air. 3. apyrexial 4. R.R rate < 50 /min. 5. parents are confident 6. advice parents : ( a).small frequent feeds. ( b). explain peak symptoms are on day 4-5. ( c). open access for 48 hrs to return if they have concerns. ( d). seek help if worsening and feeding difficulties. 7 pedia.Dr.TareqL3 Fatima Abd Al Bari BRONCHIOLITIS OBLITERANCE Un common form of chronic bronchiolitis in which there is endobronchiolar granulation tissues and peribronchiolar fibrosis , this most commonly caused by adenovirus and less commonly by measles ,influenza ,pertusis And M. pneumonia. Most like acute bronchiolitis ,but the course progress often after a period of improvement with increasing respiratory distress with poor respond to bronchodilator Treatment : No specific treatment just supportive with trial with steroid and Bronchodilator. 3-LUNG ABSCESS. Lung abscess is a suppurative process resulting in destruction of pulmonary parenchyma and formation of cavity containing purulent material. Causes : 1.aspira on of infected material when the local defense mechanism are overwhelmed by surgery or virulent microorganism. In recumbent position the posterior segments of upper lobes most affected. In erect position the basilar segments of the lower lobes most affected. 2. pneumonia caused by aerobic pyogenic M.O. like staph. 3. bronchial obstruc on by tumor or foreign body. 4. metasta c lung abscess secondary to bacteremia or due to septic thrombophlebitis. 5.rare may caused by amoebae. Clinical manifestation :- Fever , malaise , anorexia ,weight loss , cough often associated With hemoptysis and producing copious amount of foul smelling or purulent sputum. There may be respiratory distress , spiking fever , chest pain and mark leukocytosis 8 pedia.Dr.TareqL3 Fatima Abd Al Bari Diagnosis :- 1-Chest x-ray shows cavity with or without fluid level surrounded by alveolar infiltration. 2- Sputum culture reveal mixture of anarobic bacteria. 3- C.T. scan and u/s used for diagnosis of lung abscess and some me guiding for aspiration Treatment of lung abscess : Treatment should be follow the culture ,but in case of an aerobic by gram stain , treatment with clindamycin or piperacillin for 4-6 wks and wait the culture. Alternative treatment allergic to penicillin is chloramphinicol or metronidazole. Many consider clidamycin the agent of choice. An bio cs should be given intravenous for at least 2-3 wks. Bronchoscopy is indicated only to identify and remove foreign body. Chest tube drainage is necessary if empyema present. Surgical drainage almost never indicated unless : 1. recurrent hemoptysis. 2. necrosis. 9