clinical consequences of respiratory infection Flashcards
what are types of respiratory infection
URTI
Acute bronchitis
Exacerbation of chronic airway disease (COPD, bronchiectasis)
Pneumonia (CXR diagnosis in hospital, clinical in community setting)
what are classifications of pneumonia
Anatomical
Lobar
Broncho-pneumonia
Diffuse
Setting
Community acquired
Hospital acquired
Ventilator related
what is the prevalence of pneumonia
Common in very young and old
345 per 100,000 year
25% hospital admission and10% to ITU
10% all LRTIs
how is pneumonia assessed clinically
Fully history – jobs, hobbies, pets, travel, risk of immunocompromised, home situation, smoking
Full examination
BP/HR/Sats
what are signs of pneumonia
reduced air entry/PN, bronchial breathing, increased vocal resonance and crackles
how is pneumonia diagnosed
Blood tests Assess for evidence of infection/inflammation Assess renal function Assess liver function Blood cultures HIV test Sputum Viral throat swab/mycoplasma Urine – legionella Ag Arterial blood gas
what does a chest x ray of pneumonia look like
consolidation in a lung lobe
can also be seen on CT
how can the severity of pneumonia be assessed
The CURB 65 score Confusion Raised blood Urea (>7mmol/L) Raised Respiratory rate (>30/min) Low BP (S<95, D <60) Age >65 years If no urea CRB 65 score score 1-4 increasing in severity
how is community pneumonia managed
(no risk factors) Rest Push fluids Analgesics Antibiotic Safety net Refer if no improvement in 48 hours
how is hospital pneumonia managed
Oxygen if required
Fluid replacement if required
Antibiotics
Critical care management
what is the bacteriology of community acquired pneumonia
strep pneumoniae most likely, then chlamydia pneumoniae mycoplasma pneumoniae haemophilus influenzae staph aureus viruses
what does antibiotic treatment of pneumonia depend on
Choice depends on Setting Severity Co-morbidities (esp resp disease) Epidemiology Patient allergies
what antibiotics treat pneumonia
Community – amoxicillin or doxycycline
Hospital – not severe – amoxicillin +/- doxycycline or doxycycline
Hospital – severe amoxicillin and doxycycline or ceftriaxone/levofloxacin
what happens after pneumonia treatment
CAP follow up: 6 week xray
why is the CAP followup 6 weeks
Clearance rates after CAP
Adults (18-50) 95% of CAP clear in 6 weeks
Older people, clearance is slower (or with comorbidities like bacteremia, multi-lobar involvement or enteric gram-negative bacilli pneumonia)
what happens if pneumonia patients deteriorate
Deteriorate – high flow oxygen
MET call – repeat clinical assessment
how is respiratory failure treated
You can save lives but kill with oxygen (worsening type 2 respiratory failure)
How it is given depends on the clinical circumstances and the patients background condition
what are patent interfaces for oxygen
Nasal cannulae
Controlled (fixed percentage – venturi masks)
Uncontrolled masks (Hudson and reservoir masks)
Oxygen reaches the patient as litres per minute (or percentage
inspired oxygen – venturi)
how is oxygen given in critical care
can give higher oxygen concentration, positive pressure and reduce work of breathing
nasal hiflow
CPAP (continuous positive airway pressure)
NV (non-invasive ventilation)
Intubation and invasive ventilation
If everything fails consider ECMO (extracorporeal membrane oxygenation)
what are the complications of pneumonia
General Respiratory failure Sepsis – multi-system failure Local Pleural effusion Emphysema Lung abscess “Organising pneumonia” – infection persists and needs treating with steroids
why may pneumonia fail to respond
Wrong or incomplete diagnosis Antibiotic problem Complication developing Underlying bronchial obstruction Approach: re-review
what is Pleural parapneumonic effusion
To be considered if patient is not responding to treatment
Can be
Simple parapneumonic
Complicated parapneumonic
Empyema
Dominant microbiology is pneumococcus but also staph, aureus and strep milleri
Consider differential diagnosis of pleural tuberculosis
what should be considered with empyema
Indications for drainage Visibly purulent effusion Radiologically loculated effusions Positive microbial culture from effusion Pleural pH less than 7.2
what should be considered with lung abscesses
Formation of abscess can be another causes of failure to respond Need to think of cause Need lavage Consider endocarditis Prolonged antibiotic course
what is the differential diagnosis for pneumonia - why they’re not recovering
LRTI and lung cancer LRTI and heart failure Pulmonary emboli/infarction Unusual Specific infections eg TB Complicating chronic bronchial suppuration eg bronchiectasis, CF
Rare
Vasculitis
Pulmonary eosinophilia
Crytogenic organising pneumonia
