IC16 LRTI Flashcards
How does acute bronchitis develop?
Usually starts off with viral URTI
acute cough due to inflammation of trachea and lower airways
What is Pneumonia?
Infection of lung parenchyma
What are the risk factors of Pneumonia (3 points) and how do they cause a susceptible host?
1) Smoking
Suppress neutrophil function, damage lung epithelium
2) Chronic lung conditions eg. COPD, Asthma, Lung cancer
Destroy lung tissue
3) Immune suppression eg. HIV, Sepsis, on glucocorticoids, Chemotherapy
Suppress immune response
Localised symptoms in Pneumonia (6 points)
Cough
Chest pain
Shortness of breath
Tachypnoea (> 22 breaths/min)
Hypoxia eg. 90-95% O2
Increased sputum production
What should be seen in chest xray?
New consolidations
Which 2 bacteria can urinary antigen show?
What is the limitation of urinary antigen test?
Strep Pneumo
Legionella
Indicates both past and current infections also
Where can collect samples to do gram stain and culture?
Pros and cons of both samples
Sputum or Lower respiratory tract samples
Sputum easier to get but easily contaminated
Lower RT sample is invasive eg. bronchoalveolar lavage
Which populations should do pre-treatment blood and respiratory gram strain and culture be done?
1) Severe CAP
2) Have risk factor for MRSA, Pseudomonas
(previously infected in past 1 year, empirically treated, hospitalised or parenteral antibiotics in last 90 days)
Definition of Community Acquired Pneumonia
<48hrs after hospital admission
Risk factors for Community Acquired Pneumonia (4 points)
History of Pneumonia
Smoking
Chronic respiratory disease
Immunosuppression
How to measure severity of Pneumonia?
CURB-65
Confusion
Urea > 7mmol/L
RR>30
BP (<90 OR <60)
Age > 65
0-1 = Outpatient
2 = Inpatient
3 or more = Consider ICU
What are the major criteria for Severe CAP based on IDSA guidelines? (2 points)
Minor criteria (not in CURB-65) (5 points)
Major
1) Need mechanical ventilation
2) Septic shock requiring vasoactive medications
Minor
PaO2/FiO2 < 250
Multilobar infiltrates
Leukopenia (WBC < 4 X 10^9)
Hypothermia (<36 deg)
Hypo and Require aggressive fluid resuscitation
What to cover for Outpatient CAP with no comorbidities?
Hence what is the treatment?
Strep Pneumo only
All oral
Amoxicillin 1g q8
Levofloxacin or Moxifloxacin
What to cover for Outpatient CAP with comorbidities
Hence what is the treatment?
Strep Pneumo
Haem Influenzae
Atypicals
All oral drugs
Strep Pneumo, Haem Influenzae coverage
Beta lactams
Amoxicillin Clavulanate
Cefuroxime
Atypical Coverage
Macrolides (Azithromycin, Clarithromycin)
Doxycycline
Have all 3 coverage
Respiratory quinolones
Moxifloxacin
Levofloxacin
What to cover for Inpatient, non-severe
Hence what is the treatment?
Big 3
MRSA (if have resp isolation in past 1 year or hospitalisation or parenteral antibiotic in past 90 days + MRSA PCR Screen positive)
Pseudomonas (if have resp isolation in past 1 year)
Treatment - all IV
Cover Big 3
Same as Outpatient w comorbidities
Ceftriaxone now an option
MRSA
IV Vancomycin OR IV/PO Linezolid
Pseudomonas
Add on Ceftazidime
Does not cover Strep Pneumo
OR
Replace beta lactam (amox-clav, cefuroxime, ceftriaxone) with:
Pip-Tazo
Cefepime
Meropenem
Levofloxacin (Can even cover atypicals)
Need to cover what for Inpatient severe CAP?
Hence what is the treatment?
Big 3 + MSSA, Burkholderia
MRSA and Pseudomonas based on risk factors
MRSA and Pseudomonas risk factor: Resp isolation in past 1 year OR Parenteral antibiotic use in last 90 days
Treatment
Beta lactam (Strep, Haem, MSSA)
Amoxicillin Clavulanic
Penicillin G
Burkholderia
Ceftazidime
Macrolides (atypicals)
Azithromycin
Clarithromycin
Respiratory Fluoroquinolones (Strep, Haem, Atypicals, MSSA)
Levofloxacin
Moxifloxacin
MRSA
IV Vancomycin OR IV/PO Linezolid
Pseudomonas
Add on Ceftazidime
Does not cover Strep Pneumo
OR
Replace beta lactam (amox-clav) with:
Pip-Tazo
Cefepime
Meropenem
Levofloxacin (Can even cover atypicals)
If have lung abscess or empyema, what to do?
Add anaerobic coverage
Metronidazole or Clindamycin
What to do if suspect Influenza?
Add Oseltamivir within first 2 days
Stop antibiotics if Influenza PCR positive
Why are respiratory fluoroquinolones not first line for CAP? (4 points)
Adverse effects
Tendonitis
Neuropathy
QTc prolongation
CNS disturbances
Hypoglycemia
Collateral damage
Reserve for Pseudomonas coverage with severe penicillin allergies
Delay diagnosis of TB
When to de-escalate empiric cover of extra stuff eg. MRSA, Pseudomonas, Burk in CAP?
After 2 days if pathogen is not isolated and patient is improving
Duration of therapy for CAP?
5 days minimum
7 days if suspect/proven MRSA, Pseudomonas
achieve clinical stability within first 2-3 days
When de-escalating CAP, what must we still cover?
SHA
What is the big 3 for HAP / VAP?
PME
Pseudomonas
MSSA
Enterobacterales
Requirements to cover for MRSA in HAP / VAP (4 points)
1) IV antibiotics use within 90 days
2) Isolation of MRSA in last 1 year
3) Hospital has >20% of MRSA cases
4) Patient has high risk for mortality
Empiric therapy for HAP / VAP? (3 classes and their drugs)
Which should only be used with MRSA coverage? and why?
Antipseudomonal Beta Lactam
Pip-Tazo
Cefepime
Meropenem
Imipenem
Antipseudomonal FQ
Levofloxacin
Aminoglycoside
Amikacin
Only with MRSA coverage (cos these do not cover MSSA)
Ceftazidime
Ciprofloxacin
How to de-escalcate for HAP/VAP?
Similar to CAP
Use single agent according to Pseudomonas susceptibility
If no positive culture, cover big 3 (PME)
Duration of therapy for HAP/VAP therapy?
7 days
will achieve clinical stability within first 2-3 days
When to use 2 anti-pseudomonal agents? (5 points)
Prior IV antibiotic use
Acute renal replacement therapy
Isolation of Pseudomonas in past 1 year
>10% of Pseudomonas isolates resistant to monotherapy
Require ventilator
What is the lowest gen Cephalosporin we can use? Why not any lower?
2nd gen (Cefuroxime, in Outpatient CAP with comorbidities)
Cos Cephalexin does not cover Strep Pneumo
whereas Cefuroxime can cover both Strep Pneumo and Haem Influenzae
Ways to prevent VAP (3 points)
- Limit duration of mechanical ventilation
- Minimise duration and deep levels of sedation
- Elevate head of bed by 30 degrees
