pneumonia Flashcards
pathophysiology of pneumonia
- infection of the lower respiratory tract
- consolidation in lower lungs
what is consolidation
alveoli filled with exudative inflammatory fluid and pus
what is a parapneumonic effusion
effusion of the pleural space
what is empyema
when parapneumonic effusion becomes infected and pus filled
what is shunting
blood passing through alveoli without the exchange of co2 and o2
what is the compensatory response to shunting
increase respiratory rate to increase ventialation to alveoli
difference between type 1 and type 2 resp failure
type 1=o2 low but co2 normal
type 2 =both o2 and co2 affeceted as rr drops so cant compensate anymore
what is uncomplicated pneumonia and o2
type 1 resp failure
give supplemental o2 in venturi mask
what is extensive consolidated pneumonia and o2
oxygenation compromised
profound type 1 rf
-deliver high o2 through high flow nasal cannulae or mechanical vent
what is prolonged hypoxic and tachypnoea to maintain o2 and o2 treatmnet
- patient starts to tire decreasing RR so switch to type 2 RF
- anaesthetist intubation and mechanical ventilation
what is chronic decompensated t2rf and treatmnet
decompensated get acidosis due to o2
- beware o2 desensitise so non invasive ventilation
- BIPAP controlled o2 not high flow anymore
exam of a consolidated lung
palpation -reduced expansion -dull percussion auscultation -bronchial or reduced breath sounds -inspiratory crackle -increased vocal resonance
exam of parapneumonic effusion
palpation -reduced expansion percussion -stony dull auscultation -decreased breath sounds -bronchial above -decrease vocal resonance -pleural rub rough crackly hoarse sound
diff dx of hypoxia and crackles
- Pulmonary oedema
- Emphysema and copd
- Atelectasis
- Fibrosis or intersitial lung disease
- Airway secretions
- Pulmonary haemorrhage
cap dx
clinical signs
- chest x-ray
- ct if suspcicion of abscess or complication
- follow up Chest x-ray in 6-8 weeks for resolution
- labs inflammatory markers,WCC and crp
- U and E as eGFR influences
- antimicrobials and urea guides the severity of the score
- arterial blood gases
- sputum culture
- pcr viral throat swab
- bronchoalveolar lavage or tracheal aspirate if intubated and ventilated
- pleural tap if effusion present
- legionella urine antigen
CURB-65 scoring and treatment
0-1 give oral amoxicillin and keep at home
2=give oral amoxicillin and clarithromycin and admit to hospital
3= give co-amoxiclav and clarithromycin iv at hospital
main pathogens of cap
s. pneum
m. pnum
s. aureus
h. infl
viruses that cause cap
- Influenza a
- Influenza b
- Rhinovirus
- Adenovirus
- Respiratory syncytical virus RSV
where is chlamydia psittaci cap normally acquired
birds
complication m.pneumonia
haemolytic anaemia with cold agglutinins
- steven Johnson syndrome
- erythema nodosum
- pericarditis
- meningoencephalitis
- guillain barre syndrome
where is leigionella pneum found
contaminated water
where is leigonella longbeachae found
contaminated soil
where is coxiella burnetti found
reservoir of bacteria in farm animals
complications s.aureus causing cap
may cause lung abscess
-beware bacteraemia and haematogenous dissemination
OR
-pneumonia may be secondary bacteramia eg infective endocarditis due to septic emboli
-get cavity lesions
pen allergy for mild cap
doxycyline or clarithromycin
pen allergy for severe cap
ciprofloxacin and vancomycin
cap vaccines
23-valent pneumococcal polysaccharide vaccine
and
annual influenza vaccine
inx of parapneumonic effusion vs empyema
parapneum
- clear
- pH >7.2
- exudate proteins
- increased LDH
- sterile
empyema -pus filled pH<7.2 -exudate and increased LDH -gram stain or culture positive
treatment of parapneum effusion
-resolves with treatment of pneumonia
treatment of empyema
- drains with US guidance
- surgical intervention if loculated
what are the complication of pneumonia
- parapneum
- empyema
- lobar collapse
- lung abscess or cavity
- myocardial infarction
- atrial fibrillation
- resp failure
- sepsis (organ failure)
- ARDS
what causes lobar collapse in pneumonia
can be due to mucous plugging starts to move up the way and blocks smaller airways resulting in collapse of lung further down
-need chest physiotherapy
what causes lung abscess pathogens
s.aureus
k.pneumoniae
or fungi
how does pneumonia cause myocardial infarction
due to pro-inflammatory state it increases platelets which can cause dvt resulting in PE and MI
pathogens of HAP
gram positives and gram negatives
risk factors for hap
recent surgery
endotracheal intubation
diff dx of hap
- PE
- decompensated chronic lung or cardiac disease
- sub diaphargmatic source of infection
- ventilator assoc. pneumonia
- atelectasis: lung collapse
- copd
- infection
- heart failure
HAP dx
- sputum
- viral throat swab
- blood cultures
- MRSA screen
what pathogens is hao predominantly
e.coli
p.aeruginosa
ie gram negative bacilli
severity score for hap
temp <36 >39 rr>20 wbc <4 or >12 multi organ hr >100
pneumonia within 5 days of being at hospital treatment
treat as cap
treatmnet of hap with only 1 severity score
doxycycline
treatment of hap with 2 or more
amoxicillin and gentamicin
pen allergy for hap
gentamicin and vancomycin
pneumona in immunocompromised host causes
pneumocystis jiroveci
empirical antibiotics for immunocompromised host
broad spec bacterial and fungal
what pathogens might be seen in a patient with a neutrophil dysfunction from chemo or malignancy
-s.aureus
-p.aeruginosa
fungus
a.fumigatus
what pathogens might be seen in a patient with t-cell dysfunction from immunosuppressive drugs or hiv infection
viral (cmv,)
mycobacteria ie tb or non tb
pneumocystis jiroveci
what pathogens might be seen in a patient with antibody production dysfunction from hypogammaglobulinaemia
encapsulated bacteria
- h.influenzae
- s.pneumoniae
symptoms of pneumocystis jiroveci pneumonia
- Fever, non productive cough and dyspnoea are predominant with insidious onset
- Exercise induced hypoxia (desaturate on walking)
what dx inx is needed for pneumocystis jiroveci
-high resolution more sensitive shows ground glass inflamamtory changes
treatment of p.jiroveci
co-trimoxazole
and
steroid if Pao2 <9.3 pka started within 72 hrs of co-trimox
aspiration pneum pathogens
aerobes and anaerobes
treatment aspiration pneum
-metronidazole
and
-amoxicillin
