Community acquired pneumonia Flashcards
Pathological definitino of pneumonia
inflammation of the lung parenchyma leading to consolidation
doesnt have to be infectious (e.g., cryptogenic causing inflammation) or bacterial (can be viruses or fungi) however usually is.
Consolidation
when areas of the lung that are normally filled with air is replaced with something else
Appears as white on X-ray
The liquid can be pulmonary edema, inflammatory exudate, pus, inhaled water, or blood (from bronchial tree or hemorrhage from a pulmonary artery).
Pneumonia has symptoms of a LRTi. They are:
pleuritic pain, cough, sputum, breathlessness
What changes would you see on CXR compared to healthy lung
shows consolidation, areas of incresaed density so whiter
What localised breathing sounds would you look out for?
respiratory crackles- reduced air entry into one section of the lung
definition of community acquired pneumonia
acquired outside the hospital or healthcare facility (didnt acquire it within 48 hours of being discharged and it wasnt incubating)
Hospital acquired pneumonia
Acquired <48 hrs into hospital admission that wasn’t incubating on admission.
Recently hospitalised patients can be treated as CAP unless additional risk factors for MDR’s/ HAP e.g. recent Ab (antibiotic) abuse
Disproportionately affects which 2 groups of people?
old and socioeconomically less well off
Typical bacterial pathogens that cause pneumonia
streptococcus pneumoniae
haemophilus influenza
staphylococcus aureus
Symptoms of typical bacterial infection causing pneumonia
Sudden onset
malaise
fever
producrtive cough
on auscultation- crackles and bronchial breath soudns are audible
Opacity related to one lobe
Bacterial pathogens associated with pneumonia
Atypical- DON’T RESPOND TO B-LACTAMS
Mycoplasma pneumonia
Chlamydia pneumoniae
Legionella pneumoniae
Symptoms of atypical bacterial pneumonia infection
Gradual onset
Unproductive cough
Dyspnoea
Auscultation is unremarkable
X-ray shows diffuse opacity- almost subtle infiltrates
Other bacteria that can cause pneumonia
Pseudomonas aeruginosa
Enterobacteriaceae
Group A steptococcus
Viral pathogens that can cause pneumonia
Influenza A and B
Rhinoinfluenza
Corona virus–> COVID-19 and SARS
Entry
Inhaled
Aspiration from oropharynx
Direst spread
Haematogenous spread
Protective factors
Lung mucosal microbiome
Immunity (innate and adaptive)
Risk factors for pneumonia
- Age >65 years
- Residence in a healthcare setting
- COPD
- HIX infection
- Cigarette smoke exposure
- Alcohol abuse
- Pharmaceuticals- PPI, inhaled corticosteroids, antidiabetic drugs
Differential diagnosis
Left ventricular failure
Pulmonary embolus
Infective exacerbation COPD
Acute asthma
TB
Emphysema
Lung neoplasm
When to consider atypical pathogens
Foreign travel
Prior antibiotics, hyponatraemia (mycoplasma)
Air conditioning exposure
Abnormal LFTs
Neurological exposure
Subacute presentation
Clinical signs to look for on examination
Fever
cyanosis, tachypnoea, dyspnoea
Tachhycardia, hypotension (think sepsis)
localising signs- dullness to percussion, bronchial breathing, crackles
AVPU- rapidly grade a patient’s level of consciousness (Alert, Verbally responsive, pianfully responsive, Unresponsive)
What measure would you use to assess the severity of pneumonia?
CURB-65
Confusion (AMTS < 8/10 Abbreviated mental test score
Urea (>7mmol/L)
Respiratory rate >/= 30 breaths/min
Blood pressure (SBP < 90mmHg), DBP =60)
Age> 65 years
a score of 0-1 is low severity 3-5 is high severity
What is the pneumonia severity index
Index to assess the severity of pneumonia. Higher the score higher the MR.
The more factors you have, the higher your suspected mortality rate is. Helps determine whether a patient can be treat as an outpatient or needs to be in.
Split into 4 main categories:
Demographics: age, nursing home residency
Co-morbidities: neoplasia, liver disease, CHF, renal disease, cerebrovascular disease
Physical exam/ vital signs: mental confusion, repiratory rate, tachycardia
Laboratroy imaging: Arterial pH, sodium, glucose, haematocrit, pleural effusion, oxygenation
Once your patient has been diagnosed whaty other investigations will you need?
Routine bloods: FBC, U and E, LFTs, CRP procalcitonin
ABG
Blood culture testing for Ab sensitivity
Sputum culture and screen
Pneumococcal/ legionella urinary antigen screening
Paired serology if they’re not responding to treatment
Where would you treat someone with a low severity pneumonia?
At home
Conraindication to outpatient therapy
Inability to maintain oral intake
History of substance abuse
Severe comorbid ilnesses
Cognitive impairment
Impaired functional status
Availability of support at home
Imaging options for pnuemonia
Lung ultrasound
Chest CT
Lung ultrasound for pneumonia
Quick
Simple
Cheap
Reliable
Assess plueral effusions
Can miss diagnosis of diffuse diseas or interstitial pneumonias
Chest CT
Provides the most information
poor access and ionizing radiation
Supportive treatment for all patients
Oxygen to keep SpO2 (oxygen sat) 94-> 98% or 88->92% if T2RF
Fluids if hypotensive
VTE (venous thromboembolism) prophylaxis
Nutritional support if prolonged illness
Sitting up for at least 20 mins a day
Chest physio review to remove sputum
British Thoracic Society (BTS) Community Acquired Pneumonia Care Bundle
- Perform CXR within 4 hours of admission
- Assess oxygen saturation and prescribe oxygen according to appropriate target range
- Calculate CURB-65 in all patients where CXR demonstrates pneumonia
- Administer antibiotics within 4 hours of diagnosis appropriate to CURB 65 score
What is the first line antibiotic used in suspected mild pneumonia?
Amoxicillin
Alternatives: clarithromycin or doxycycline
Amoxicillin
CLASS: semisynthetic penicillin derivative antibacterial
CHEMSITRY:
PHARMACOLOGY: Action: bacteriocydal. attaches to cell wall of susceptible bacteria and kills by inhibiting the cross-linkage of peptidoglycan polymer chains that make up the major component of the bacterial cell wall
penicillin allergy beware
Amoxicillin rash may also be an indicator of infectious mononucleosis in patients with EBV infection
Doxycycline
Broad spectrum antibiotic
Tetracycline
Bacteriostatic- inhibits bacterial protein synthesis- binds the 30S ribosomal subunit, prevents the binding of transfer RNA to messenger RNA at the ribosomal subunit
Amino acids therefore cant be added to polypeptide chains meaning that no new proteins can be made
What medication should be given to severe pneumonia
co-amoxiclav (consider adding clarithromycin)
If atypical pneumonia suspected add…?
clarithromycin
If aspiration pneumonia treatment
Antibiotics not needed unless concerned about secondary infection (co-amoxiclav)
Discahrge and follow up
Discharge when established on oral Ab’s and the ‘abnormal’ vitals are normal
Patient should have CXR 6 weeks after discharge
Explain to patients/ carers that they should see the GP is symptoms do not begin to improve within 3/7 weeks of starting Ab’s and return to ED if they worsen
Pneumnonia patient information leaflet
What to do if the patient isnt getting better
Consider differential diagnosis- empyema, lung abscess, lung cancer
Differnt organism? reculture
Bronchoscopy with lavage– TB?
Empyema
aka pyothorax
Condition in which pus gathers in the pleural space
Lung abscess
Death of lung tissue
Collection within it is either air or fluid
check for spiking temperature despite antibiotics
How long does it take to feel better after pneumonia?
can take a few months to feel better
rest and build up your strangth again
