Occult pneumonia
林口長庚醫院
兒童一般醫學科
吳志德醫師
2011-4-13
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• Occult: hidden
• No obvious lower respiratory tract infection
symptoms/signs
– Tachypnea
– Respiratory distress
– Abnormal breath sound on physical exam
• CXR: pneumonic patch
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Community acquired pneumonia
• Clinical presentation
– Fever and cough
– Difficulty feeding/restlessness (young infants)
– Pleuritic chest pain (pain with respiration)
– Abdominal pain
– Fever and leukocytosis
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Fever
• Non-specific and variably present
• In young infants, afebrile pneumonia due to C.
trachomatis or other pathogens
• May be the only sign of occult pneumonia
– 26% of 146 children (60 bpm
– 2-12 mo: >50 bpm
– 1-5 yr: >40 bpm
– ≥5 yr: >20 bpm
• RR may increase by 10 bpm/degree of fever
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Respiratory distress
• Hypoxemia
– SpO2≤96% 2.8 times more frequent in children with
pneumonia
• Retractions
– 2.4 to 2.5 times more frequent in children with
pneumonia
• Nasal flaring
– 5 times more frequent in children with pneumonia
• Grunting
– Severe disease and impending respiratory failure
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Lung examinations
• Crackles (rales)
• Decreased breath sound
• Bronchial breath sound
• Bronchophony
• Tactile fremitus
• Dullness to percussion
• Wheezing
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Severity assessment
• BT> 38.5°C
• RR> 70 bpm ( 50 bpm in older
children
• Moderate to severe retraction
• Nasal flaring
• Cyanosis or hypoxemia
• Intermittent apnea in infants
• Grunting
• Feeding difficulty or dehydration
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Blood tests
• CBC
– WBC 35 to 60 mg/L (odd ratio 2.6)
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Radiologic evaluations- indications
• Severe disease
• Confirmation of diagnosis when clinical
findings are inconclusive
• Exclusion of alternate explanations for
respiratory distress (foreign body aspiration,
heart failure)
• Assessment of presence of complications
• Suspicious occult pneumonia
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Occult pneumonia
• In young children (3-36 mo) with fever> 39°C
and leukocytosis≥ 20000
• In older children with fever> 38°, cough, and
leukocytosis≥ 15000
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Bacterial pneumonia
• Abrupt onset
• Febrile patient appearing ill or toxic
• Moderate to severe respiratory distress
• Focal auscultatory findings limited to involved
segment
• More complications
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Atypical pneumonia
• Abrupt onset
• Resulting from mycoplasma or chlamydia
• Fever, malaise, myalgia, headache, photophobia,
sore throat
• More frequent wheezing
• M. pneumonia:
– Skin rash, hemolytic anemia, polyarthritis, pancreatitis,
hepatitis, pericarditis, myocarditis
• Afebrile pneumonia of infancy
– C. trachomatis, CMV, Ureaplasma urealyticum
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Viral pneumonia
• Gradual onset with preceding URI symptoms
• Patient does not appear toxic
• Diffuse and bilateral auscultatory findings
• More frequent wheezing
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Clinical predictors of occult
pneumonia
• Cough: 1.24
• Prolonged cough (>10 days): 2.25
• Fevere> 3 days: 1.62
• Fever> 5 days: 2.24
• WBC≥ 15000: 1.76
• WBC≥ 20000: 2.17
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