LOWER RESPIROTARY TRACT INFECTION 1- pneumonia Pneumonia is an inflammation of the lung parenchyma ( the lower portion of respiratory tract consisting of the respiratory bronchiole ,alveolar ducts ,alveolar sacs and alveoli ) are is associated with consolidation of the alveolar space . TYPES OF PNEUMONIA 1 . Infectious pneumonia . 2 . hydrocarbon pneumonia . 3 . aspiration pneumonia . 4 . radiation pneumonia . 5 . lipoid pneumonia . ( pneumonitis is a general term for lung inflammation that may or may not be associated with consolidation ) .
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 para influenza .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 and diffuse bilateral infiltration 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 and influenza in sever pneumonia .
Amantidine for influenza type A .
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 manifestation 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 .
DIAGNOSIS OF PNEUMONIA
1- Definitive diagnosis of pneumonia require identification of the causative organism .2- Sputum for culture ( not easily taken for children ) .
3-Chest x-ray often shows lower consolidation and pleural effusion or pneumopyothorax that complete pneumonia .
4-WBC is elevated with predominance of neutrophil , 5-if M .pneumonia suspected -Cold agglutinin are present in peripheral blood film .
6-Blood culture is essential for Ag detection
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 .
treatment
The following general guidelines take in consideration :1.age .
2.severity of illness .
3.presence of illness in the family .
4. previous hospitalization .
5. lab. Studies must be considered when antibiotics is chosen .
( 1) . Children younger than 6 yrs with mild to moderate illness can be observed at
home and given oral antibiotics 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 ) after 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 . antipyretic may be needed .
3. adequate intake of fluid must be ensured .
4. good nursing and the infant position 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 secretion and encuorge cough .
Indication of hospitalization in pneumonia
1-failure to response to oral antibiotics .2-inability to take oral antibiotics because of vomiting or poor compliance .
3-lobar consolidation in more than one lobe .
4-immune suppression .
5-moderate to severe respiratory distress .
6-empyema .
7-abscess or pneumatocele .
8-underling cardiopulmonary diseases.
2-BRONCHIOLITIS
A common disease of lower respiratory tract of infant results from inflammatory obstruction of small airways ..Respiratory syncytial virus ( RSV ) is the causative 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 .
Bronchiolitis 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 appetite 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 wheezing are Audible .
Chest x-ray finding : 1 . hyper inflation of the lung and increased antero –posterior diameter .
2 . scattered area of consolidation .
3 . sometimes 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 aspiration and localized sings on
Examination.
3 . Bacterial bronchopneumonia that associated with generalized
obstructive pulmonary over inflation
4 . heart failure , usually with cardiac murmur
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.Hospitalization of infant with respiratory distress .2.cool place and humidified oxygen to relieve hypoxemia and reduce water loss from tachypnea .
3.avoidance of sedation to irritable infant.
4.sitting 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 . antibiotics to treat or prevent bacterial invasion .
8 . steroid may be used but sometime may be harmful .
9 . bronchodilators are frequently used .
10 . those patients with impending respiratory failure requiring ventilatory help . 11 . as prevention 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 .
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 parynchyma and formation of cavity containing purulent material .Causes :
1 .aspiration 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 obstruction by tumor or foreign body .
4 . metastatic 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
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 sometime 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 .
Antibiotics 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 .