LOWER RESPIRATORY TRACT INFECTION

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LOWER RESPIRATORY TRACT INFECTION

• Dr. Hayat Z Kamfar
• Assisstant Professor Consultant Pediatrician

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• Learning Objectives
• After completing the lecture students should be
  able to
• Identify common lower respiratory tract
  infection during childhood
• describe the findings of pneumonia on phy.
  examination of different age group and of
  bronchiolitis in infants
• name the most important cause of bacterial
  pneumonia in children older than 6 months of age
• delineate the differential diagnosis of atypical
  pneumonia in school-age children and adolescents
• describe the treatment of pneumonia and
  bronchiolitis in infants and young children
• characterize the circumstances under which a
  follow-up chest radiography is required for
  pneumonia

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Introduction Clinical syndromes 15 ? croup 34
? tracheobronchitis 29 ? bronchiolitis 29 ?
pneumonia Overall attack rate of pneumonia in
all ages was 4-6 cases/100 children/year BRONCHIO
LITIS PNEUMONIA
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Pneumonia .continue
Pathphysiology Clinical manifestations Cough G
runting Chest pain Tachypnea Retraction Auscultati
on Cyanosis Additional clues Chest
radiograph Laboratory tests
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• CLINICAL PRESENTATIONS
• Newborn
• Infants (1-6months)
• Toddlers/preschoolers(7m-5y)
• Child/adolescent(6y-18y)
• Well-appearing
• Ill-appearing

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NEWBORNS An infant is grunting on arrival in
the nursery from the delivery room. He has a
respiratory rate of 75 b/min and substernal
retractions. Pulse oximetry on room air is 85,
and he has fine crackles on auscultation. Chest
radiograph demonstrates a ground-glass appearance
with air bronchograms. He appears ill.
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• Group B streptococcal disease-most common- cause
  of LRI in newborns
• Most likely in utero acquired infection
• Affected infants frequently develop fulminant
  illness-hours of delivery
• Fatal if not detected early
• Initial therapy includes mechanical support- if
  necessary- and I.V antibiotics
• Ampicillin (100mg/kg as initial dose ?
  200mg/kg/24hrs)
• Gentamycin (2.5mg/kg as initial dose ?
  7.5mg/kg/24hrs)

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INFANTS A) FEBRILE/ILL APPEARING A
3-month-old child develops mild cough and nasal
discharge. On the forth day of the illness, she
stops feeding, cough becomes prominent, and
temperature rises to 102 F (38.8 C). Physical
examination reveals a respiratory rate of
60b/min, sternal and substernal retractions, and
diffuse crackles. A lobar infiltrate is seen on
chest radiograph.
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• High fever in an infant is more likely to be the
  result of invasive bacterial disease
• Pathogens in this age group include
• Streptococcus pneumoniae
• Haemophilus influenzae serotype B (HIB)
• Staphylococcus aureus (suggested also by the
  presence of pleural effusion or pneumothorax on
  presentation)
• Approach to a febrile infant suspected to have
  bacterial pneumonia should include full septic
  screen
• Infants with febrile pneumonia should be
  hospitalized and initial parenteral antibiotics
  should include
• Nafcillin or flucloxacillin (100mg/kg/24hrs)
• Cefotaxime (100-150mg/kg/24hrs) or cefuraxime
  (100-150mg/kg/day)

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B) Afebrile/Well appearing A 2-month-old girl
presents with progressive coryza, cough, and
difficulty feeding. She has paroxysms of
"staccato" cough with nasal congestion and
respiratory rate of 55 b/min. Her temperature is
normal. Auscultation of the chest reveals diffuse
rhonchi and coarse crackles. There are mild
subcostal retractions. Chest radiograph
demonstrates hyperinflation and diffuse,
increased interstitial markings. The infant
appears well. She is feeding, playful, and
smiling.
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• Most commonly identified pathogens are Chlamydia
  trachomatis, Ureaplasma urealyticum,
  cytomegalovirus and Pneumocystis carinii.
• RSV, adenovirus, and parainfluenza viruses also
  can cause pneumonia in otherwise well infants.
• Bordetella pertussis should also be expected even
  if there is no characteristic "whoop".
• Infants who have afebrile pneumonia often will be
  evaluated and treated in an outpatient setting.
• Inability to eat, respiratory distress, and
  hypoxemia are criteria for hospitalization.
• Although viruses cause the majority of LRIs in
  this age group, but if Chlamydia or B.pertussis
  expected the drug of choice is erythromycin
  (50mg/kg/day)- an alternative is sulfamethoxasole
  (septrin) at (50mg/kg/day) for a total of 7-10
  days.

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TODDLERS/PRESCHOOLERS A) febrile/well
appearing An 18-month-old child has
an 8-day history of progressive nasal congestion,
coryza, hoarseness, and cough. The cough is worse
at night. She has had occasional post-tussive
vomiting. In fact, the emesis is the parent's
chief complaint. Her cough sounded "tight"
initially but now sounds "wet". She had a
"low-grade" fever initially, but now is afebrile.
Two siblings are sick at home with "colds".
Auscultation reveals diffuse heterophonous
wheezing and inspiratory crackles. The child
otherwise appear well.
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• The vast majority of pneumonia among toddlers and
  preschool children results from viral infection
• Etiologic agents followed seasonal pattern
• RSV in rainy, winter months
• Parainfluenza in the late summer and autumn (when
  croup also seen)
• Influenza with epidemics in winter
• Daily outpatient follow-up after the initial
  diagnosis of viral pneumonia will ensure that no
  patient, who develops a more severe, secondary
  bacterial infection will be missed

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B) Febrile / ill appearing Following 2 to 3
days of a relatively minor cold, a 4-year-old
child has acute onset of fever to 39C and
chills. He has a productive-sounding cough.
Examination reveals no retractions, but a
respiratory rate of 40 b/min and fine crackles in
the area of the left base. Chest radiograph
demonstrates a "round" infiltrate in the left
lower lobe. The child is ill appearing, but he is
alert and cooperative and is in no respiratory
distress.
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• Pneumococcus is the most common bacterial
  pathogen causing febrile pneumonia in children
  and adults
• The clinical syndrome is characteristic and
  distinctive
• acute onset of high, spiking fever, with chills,
  cough, and sputum production
• Leukocytosis frequently will be present on the
  blood count
• Chest x-ray will reveal a typical lobar
  pneumonia, a small parapneumonic effusion can be
  present
• Neisseria meningitidis infection also may present
  with same picture of febrile pnemonia, but it
  usually is accompanied by signs of
  meningococcemia
• Outpatient therapy is sufficient for an otherwise
  healthy, alert, and cooperative child, but the
  patient should be followed daily

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• Continue..
• Antibiotics of choice is
• Penicillin VK (25-50 mg /kg/day as TID)
• Amoxacillin 40mg /kg/day as TID)
• Patients who does not tolerate oral medication,
  may benefit from initial dose of I.M ceftriaxone
  (50mg/kg with lidocaine)
• Hospital parenteral antibiotics is reserved for
  severely ill, and/or who has evidence of
  respiratory insufficiency
• Aerosolized bronchodilators (children who have
  wheezing, a strong F/H of asthma or allergy, or
  signs of airway obstruction)
• If hypoxia is present ? hospitalization, nasal
  oxygen, and I.V penicillin (150,000U/kg/day as
  QID) or ampicillin (100mg/kg/day as QID).
  Cefuraxime (150 mg/kg/days TID)

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CHILDREN/ADOLESCENT A) febrile/well-appearing A
12-year-old develops mild cough and headache that
progresses with the onset of abdominal pain and
vomiting. After 48 hours, the cough becomes
productive and she develops left-sided chest
pain. She also has ear pain. Examination reveals
a temperature of 38C, a respiratory rate of 28
b/min, and crackles in the mid-left lung field.
Palpation of the trachea causes a paroxysm of
cough. Chest radiograph reveals bilateral
interstitial infiltrates.
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• Atypical bacteria are responsible for a
  significant proportion of LRT disease in
  adolescent and school-age children
• Mycoplasma pneumoniae and C. pnumoniae are the
  identified pathogens
• M. pneumoniae is highly contagious and tends to
  affect up to 75 of susceptible household
  contacts
• No single characteristic clinical or radiological
  picture of atypical pneumonia in older child
• Prodrome of headache and abdominal symptoms has
  been described often
• Onset usually is insidious, and fever is of low
  grade
• CXR may show lobar infiltrates, bronchopneumonia,
  or even pleural effusion
• Cold agglutinin will be detectable in 50 of
  patients who have M. pneumoniae infections
• Specific serologic studies for mycoplasma and
  chlamydia are available

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• Continue..
• Both pathogens are susceptible to erythromycin,
  esteolate form often is tolerated better than the
  ethylsuccinate form
• Recommended dose of the estrolate form is 30-40
  mg/kg/day as TID or BID
• Tetracycline (25-50 mg/kg/day as QID) and
  doxycycline (2-4 mg/kg/day as BID) also effective
  and can be used in children gt 8 years old
• Azithromycin is effective, but not recommended
  for children lt 16 years
• A significant number of adolescent and young
  adults are susceptible to B. pertussis infection
  (immunity up to 18 years after routine
  vaccination is only for 80). This should be
  suspected especially if paroxysm of cough
  prolonged gt 2-3 weeks
• Pertussis is a self-limited infection in this age
  group

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B) Febrile/Ill appearing A
15-year-old boy who has static encephalopathy and
psychomotor delay develops fever to 39C and
cough. The parents report that he often appears
to "choke" on both food and his own secretions.
The patient has poor oral hygiene, inflamed gums,
and several cavities. Crackles can be heard over
the posterior lung field. Chest radiograph
reveals consolidation and a cavity with an
air-fluid level.
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• Pulmonary abscess is considered to primary- in
  otherwise healthy patients and secondary- in
  neurologically impaired or immunocompromised
  patients.
• 75 of all primary abscesses are complications of
  staphylococcal pneumonia.
• Secondary abscess may be caused by pneumococci or
  alpha-hemolytic streptococci. More often
  polymicrobial and involves anaerobic organisms.
• All pulmonary abscesses must be treated with
  parenteral antibiotics until resolved.

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• Continue.
• For primary- cefuraxime (150 mg/kg/day as TID )
  or ticaracillin/calvulante (300 mg/kg/day as QID)
• For secondary - clindamycin phosphate (30
  mg/kg/day as QID) or ticaracillin/calvulanate.
• Surgical drainage is a treatment of exception,
  considered only in patients who remain
  symptomatic and febrile for gt a week on
  appropriate therapy
• Occasionally, foreign bodies could be the cause
  for unresolved abscess- bronchoscopy.

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BRONCHIOLITIS Definition Epidemiology Common
causes RSV (commonest) Parainfluenza
virus Influenza type A virus Adenovirus Rhinovirus
Mycoplasma pneumonia Pathogenesis
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• Clinical manifestations
• H/O U.R.T.I.
• Poor feeding
• Fever
• Tachypnea
• Tachycardia
• Cyanosis (severe cases)
• Restlessness
• Otitis media
• Nasal congestion
• Chest findings

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• Diagnosis
• Management
• Symptomatic and supportive
• Antiviral (ribavirin)
• ??steroids
• ?? bronchodilators
• prevention

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• Sammary
• lower respiratory tract infection is a common
  medical problem in pediatric age groups
• bronchiolitis and pneumonia is a frequent
  clinical presentation in young an old children
• most of these cases are due to viral infection,
  however, some severe cases may need hospital
  management and close observations

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• Sammary continue.
• most of these cases diagnosis depends on
  clinical presentation and minimum laboratory and
  radiological investigations may be needed
• most of these cases recovered smoothly with
  appropriate management unless an underlying lung
  pathological or systemic disease may worsen the
  condition or continue with chronicity
• appropriate follow-up of these patients in OPC
  is appreciated especially after discharge from
  hospital

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THANK YOU
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• Sammary
• lower respiratory tract infection is a common
  medical problem in pediatric age groups
• bronchiolitis and pneumonia is a frequent
  clinical presentation in young an old children
• most of these cases are due to viral infection,
  however, some severe cases may need hospital
  management and close observations

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• Sammary continue.
• most of these cases diagnosis depends on
  clinical presentation and minimum laboratory and
  radiologic investigations may be needed
• most of these cases recovered smoothly with
  appropriate management unless an underlying lung
  pathological or systemic disease may worsen the
  condition or continue with chronicity
• appropriate follow-up of these patients in OPC
  is appreciated especially after discharge from
  hospital

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THANK YOU