Paediatric Respiratory Flashcards
What is pneumonia?
inflammatory condition affecting alveoli of the lungs
mc - secondary to bacterial infection
causes of pneumonia
bacterial - mc :
- streptococcus pneumoniae - 80%. high fever, rapid onset and herpes labialis. - vaccine available
- haemophilus influenzae - common in copd pts
- staph aureus - following influenza infection or pts with CF
mycoplasma pneumoniae - atypical pneumonia - dry cough and atypical chest signs/x ray finds. autoimmune haemolytic anaemia and erythema multiforme poss seen
legionella pneumophilia - atypica. hyponatremia and lymphopenia common. - secondary to infected air conditioning units.
klebsiella pneumoniae - alcoholics
pseudomonas aeruginosa - pt with CF or bronchiectasis
moraxella catarrhalis - in immunocompromised pts or those with chronic pulmonary disease
viral
fungal :
- pneumocystis jiroveci - seen in hiv pts. dry cough exercise induced desaturations and absence of chest signs
Characteristic Chest signs of pneumonia
bronchial breath sounds - harsh inspiratory and expiratory breath sounds) -
focal coarse crackles - caused by air passing through sputum in the airways
dullness to percussion - due to lung tissue filled with sputum or collapsed
What is idiopathic interstitial pneumonia?
non infective causes of pneumonia.
eg:
- cryptogenic organising pneumonia - form of bronchiolitis that might come as a comp of Rheumatoid arthritis or amiodarone therapy
CAP VS HAP
community : most pts.
if develop within 48 hrs or more of admission : hap
symptoms of pneumonia
cough
purulent sputum (rust coloured/blood stained)
dyspnoea
chest pain: poss pleuritic
fever
malaise
haemoptysis - cough up blood
delirium
signs of pneumonia
signs of systemic inflammatory response:
- fever
-tachycardia
- hypotension
-confusion
tachypnoea
reduced oxygen saturations (95% or below 88% in copd)
auscultation:
- reduced breath sounds
-bronchial breathing
-crepitations/crackles
dullness on percussion (fluid)
Investigations for pneumonia
chest x ray : consolidation - opacity on x ray film in area of infection
- poss effusion
bloods:
fbc - neutrophilia in bacterial infection (raised wbc)
urea and electrolytes:
- check for dehydration
crp: raised
blood culture
abg: if ox sats low or pt has pre-existing resp disease eg copd.
sputum sample: diagnose causative organism after culture.
legionella antibodies if intermediate-high risk pts.
Risk stratification for pneumonia
what to do based off what scores? in hospital
CURB-65
C - confusion - abbreviated mental test score 8 or less/10
U - urea over 7 mmol/l
R - resp rate 30 or more/min
B - bp stystolic 90 or less and diastolic 60 or less
65 - AGE 65 OR MORE
home based care: 0 or 1 - low risk - <3% mortality risk
hospital : 2 or more - intermediate risk - 3-15%
intensive care if 3 or more - high risk - 15% mortatility
With reference to crp, how do you assess whether to give abx to pneumonia pts or not?
crp under 20 - dont give abx
crp 20-100 - consider delayed abx prescription
crp over 100 mg/L - offer abx therapy
Risk factors of pneumonia
age under 5 or over 65
smoking
recent viral RTI
chronic resp diseases: cystic fibrosis and COPD
immunosuppression: cytotoxic drug therapy and HIV
ivdu
other non-resp co-morbidities: dm or cv
pt at risk of aspiration: those with neuro diseases such as Parkinson’s disease or those with oesophageal obstruction.
Pathophysiology of pneumonia
pathogen entered the lower respiratory tract, inflammatory cascade begins.
neutrophils migrate to infected alveoli.
release cytokines.
activate immune response and induce fever.
accumulation of fluid and pus within alveoli that impairs gas exchange,
leads to hypoxic state which is characteristic of pneumonia
pneumonia in children - mc cause
treatment in kids
s.pneumoniae - mc causative agent of bacterial pneumonia in kids
amox : 1st line
macrolides add if no response
macrolide: if mycoplasma or chlamydia suspected
in pneumonia with influenza: co-amoxiclav
characteristic features of pneumococcal pneumonia:
rapid onset
high fever
pleuritic chest pain
herpes labialis - cold sores
Mx of Pneumonia : CAP
low-severity CAP:
- amox - 1st line
- if penicillin allergic - macrolide or tetracycline
- 5 day course of abx.
Mx of moderate-high severity CAP:
- dual abx therapy with abx + macrolide
- 7-10 day course.
- beta-lactamase stable penicillin like co-amoxiclav, ceftriaxone or piperacillin with tazobactam and a macrolide in high severity.
Discharge Criteria for Pneumonia
if in the past 24 hrs they have had 2 or more of these cant discharge:
- temp over 37.5
- rr over 100 breathspm
- hr over 100 bpm
- systolic bp 90 or less
-ox sats under 90% on room air - abnormal mental status
- inability to eat without assistance.
how quick should symptoms resolve in pneumonia?
1 week - fever stop
4 week - chest pain and sputum reduced
6 week - cough and breathlessness reduced
3 months - most sx resolved poss still fatigue
6 months - normal
in pneumonia when should i repeat cxr after clinical resolution
6 weeks
ensure consolidation is resolved and no underlying secondary abnormalities eg lung tumour
What is mycoplasma pneumoniae?
atypical pneumonia - younger pts.
epidemic every 4 yrs approx.
why does atypical pneumonias not respond to penicillin’s or cephalosporins?
lack peptidoglycan cell wall
features of mycoplasma pneumonia
prolonged and gradual onset.
flu like sx classically precede a dry cough
bilateral consolidation: X-RAY
how would you investigate for a mycoplasma pneumoniae?
mycoplasma serology
positive cold agglutination test - peripheral blood smear may show rbc agglutination
management of mycoplasma pneumonia
doxycycline (tetracycline) or a macrolide - eg erythromycin/clarithromycin
or
fluoroquinolones - levofloxacin
Complications of mycoplasma pneumonia
- cold agglutins (IgM): may cause haemolytic anaemia, thrombocytopenia
- erythema multiforme, erythema nodosum
- meningoencephalitis, Guillain-Barre syndrome and other immune-mediated neurological diseases
- bullous myringitis: painful vesicles on the tympanic membrane
- pericarditis/myocarditis
gi: hepatitis, pancreatitis
renal: acute glomerulonephritis