Therapeutics - Bacterial Pneumonia Flashcards
What usually precedes a bacterial pneumonia?
Viral infection
What is the definition and criteria of Community Acquired Pneumonia?
- Acute infection of parenchyma
- Associated with sx of acute infection
- Accompanied by:
- acute infiltrate on CXR or auscultory findings
- altered breath sounds
- Usually 2 of: fever >37.8, hypotheria, rigors, sweats, new cough +/- sputum change in colour, chest discomfort, dyspnea
- fatigue, myalgias, ab pain, anorexia, h/a
Where is bacterial pneumonia most apparent on CXR?
Right lower lobe pneumonia
What is by far the most common bacterial pathogen in CAP?
In what patient population is it most prevalent?
What are some features of it’s onset?
- S. pneumoniae
- splenic dysfunction/absence; chronic cardiopulmonary disease; diabetes; renal disease; HIV
- severe, acute, lobar, sudden onset
What are some risk factors for resistant S. pneumo?
- Abx use: beta-lactam; macrolide; quinolone in p2m
- > 65 years
- daycare exposure
- alcoholism
- immunosuppresion
How does CAP from M.pneumoniae look like?
Non-pulmonary sx? When is it more common? How is it spread?
- Gradual onset fever, h/a, malaise
- followed by 3-5 days w/ persistant hacking cough that’s initially nonproductive
- Non-pulmonary sx: N/V, myalgias, arthralgias, polyarticular arthritis, skin rashes
- fall and winter more common
- close personal contact
C. pneumoniae
- in what populations mostly
- what does it look like? Sx?
- Young adults and elderly (immunity incomplete - reinfection common)
- Gradual onset, fever and h/a common; elderly: severe
What is the second most common cause of pneumonia?
More likely happens in which population of patients?
Most common presenttion?
- H. influenzae
- patients with comorbid diseases (diabetes, CVD, etc.)
- Bronchopneumoniae or AECOPD
Pneumonia Dx
- Patient hx?
- Physical findings?
- Gold standard and tests used?
- fever, chills, dyspnea, pleuritic chest pain, cough, delirium, confusion in elderly
- high RR, fever >37.8, low O2sats, rales/rhonchi
- CXR, sputum culture in hospitalized, CBC/WBC/bands, increased glucose, electrolytes, Cr, ALT
What is a PSI? When is it used?
- Pneumonia Severity of Illness (Risk Assessment)
- Determines need for ICU admission
What is CURB65?
Confusion Uremia Respiratory Rate BP (Sys <90, Dia <60) >65 years old
What is the duration of treatment for CAP outpatient?
A minimum of 5 days and until afebrile 48-72h
If Azithromycin, 3 days
What is a non-infectious outcome of pneumo?
Acute cardiac events (MI, Afib, arrhythmias) and increased mortality
Prevention methods of pneumo?
- Influenza vaccine
- Pneumococcal vaccine
- Handwashing
- Smoking cessation
- Rehabilitation programs
Pathogens found in Outpatients if no comorbid factors?
S.pneumo
M.pneumo
C.pneumo
Pathogens found in outpatient CAP if comorbid conditons present?
-S.pneumo
-H.influenzae
-S.aureus (influenza, diabetes)
-M.catarrhalis
Enterobacteraciae
M.pneumo
L.pneumo
C.pneumo
Influenza in season
OUTPATIENT WITH NO COMORBID CONDITIONS
- First line treatment
- Alternatives
First line treatment:
Doxycycline 200mg stat, then 100mg bid x5-7 days
+/-
Amoxicillin 1g tid x5-7days
(if lobar pneumonia, fever, rigors, recent abx therapy, local S.pneumo tetracycline resistance >15%)
Alternatives:
Azithromycin 500mg daily x3 days
+
Amoxicillin 1g tid x5-7 days
OR
Clarithromycin 500mg bid (XL: 1g daily) x5-7days
OUTPATIENT WITH COMORBID CONDITIONS:
First line treatment
Amoxicillin 1g tid x5-7 days
OR
Amoxi-clav 875mg bid x5-7 days
+ either one of:
Doxycycline 200mg stat, then 100mg bid x5-7 days
OR
Azithromycin 500mg daily x3 days
OR
Clarithromycin 500mg bid (XL: 1g daily) x5-7 days
Why is doxycyline a good choice for CAP?
- Good activity against typical CAP pathogens: s.pneumo, beta-lactamase producing H.influ, M.catarrhalis, atypicals
- less resistance than macrolides in S.pneumo (18% vs 31%)
- Doesn’t increase penicillin resistance
- Excellent PK/PD (high serum and lung levels)
- Less expensive than newer macrolides or respiratory quinolones
Diagnosis for Nursing Home Acquired Pneumonia
-CXR
-if CNR not available:
Tachypnea
>25 increased morbidity and mortality
>40 transfer to hospital
Plus 2+ of following:
Fever
New productive cough
Pleuritic chest pain
Crackles, wheezes
new onset delirium
dyspnea
Hypoxemia
Treatment for NHAP First line
Amoxicillin +/- Doxycycline OR Azithromycin OR Clarithromycin
Hospital acquired pneumonia First line Treatment (Late onset)
-Most responsible pathogen
Ceftriaxone OR Levofloxacin +/- Gentamicin
-Enterobactericiae
Ventilator Associated Pneumonia
- Top 3 pathogens
- First line treatment
Enterobactericiae
Pseudomonas
S.aureus/MRSA
Pip-Tazo OR Imipenem/Meropenem
If MRSA suspected, add Vancomycin
What is procalcitonin guided abx therapy and what can it be used for?
What levels distinguishing healthy and infections?
What is the cutoff for an RTI needing abx?
Has it been established in guidelines yet?
-Procalcitonin is a serum biomarker that may be used to distinguish bacterial and fungal infections from viral. It can also help guide when abx should d/c with other clinical criteria
-In healthy people: v. low level
In infections, can raise to high levels >0.5 ng/mL, in very severe often >10 ng/mL
-In “typical bacterial or legionella” pneumonia, cutoff is 0.25 ng/mL or higher for needing abx
-Not yet established in guidelines, but guidelines under review now
When should CRP be used as a guide for pneumonia?
In patients with sx of LRTI in primary care, consider CRP test if after clinical assessment it is not clear whether abx should be prescribed
What effect does adding macrolides to a typical abx therapy in pneumonia has?
What is the benefit of this?
What is the concern of this?
Adding macrolide to a beta-lactam therapy has shown to have an anti-inflammatory effect: suppresses inflammatory cytokines and adhesion molecules
- Benefit: reduced morbidity and mortality
- Concern: increased number of cardiac deaths with azithromycin (QTc prolongation)
What effect do statins have in treatment for pneumonia?
Statins inhibit activation of G proteins, reducing inflammation - better outcomes
