26 Lower respiratory tract cases Flashcards
What are the common pathogens causing bronchitis? How do you diagnose/confirm?
- Bordetella pertussis= “Whooping Cough” (Afebrile cough illness in adults; Public health importance of treatment since easily transmissible)
- Mycoplasma pneumoniae/Chlamydophila pneumoniae= often self-limited and may not need antibiotics (yes, just like viral in that sense)… Beta-lactams would not help (organisms lack cell wall)
Diagnosis: PCR based assay from nasopharyngeal specimen
What antimicrobial do you use for bronchitis?
- Azithromycin for Bordetella pertussis (TMP/ SMX if allergy to macrolides)
- Azithromycin, Doxycycline, Moxifloxacin (or Levofloxacin) for Mycoplasma/Chlamydophila
What are some causes of community acquired pneumonia (CAP)?
- Strep pneumoniae
- H influenzae
- Moraxella catarrhalis
- Atypical Pathogens (Mycoplasma, Chlamydophila, Legionella)
How do you treat outpatient CAP (No recent antibiotics No co- morbidities)?
- Treatment is often empiric
- If you end up finding diagnosis specifically (which is rare) and target drugs specific to that organism
- Doxycycline/Azithromycin
How do you treat outpatient CAP with co- morbidities OR recent antibiotic exposure
- Respiratory Fluoroquinolones (Levofloxacin/Moxifloxacin)
- Concern is that the organisms may be resistant to Azithro or Doxycycline (main one we are worried about is Strep pneumo)
How do you treat inpatient CAP?
- Ceftriaxone (to cover typical bugs) PLUS Macrolide (Azithromycin; to cover atypical bugs without cell wall) OR Levofloxacin/ Moxifloxacin (cover both typical and atypical)
- Still covering same bugs as outpatient but stakes are higher so use drugs that have reliable activity against Strep pneumo (Azithro and Doxycycline do not provide reliable coverage – but in uncomplicated outpatient CAP we often do not worry that much)
What is HAP?
Hospital acquired pneumonia
**pneumonia occuring more than 48 hours after admission that was NOT incubating at admission
What is VAP?
Ventilator acquired pneumonia
**pneumonia occuring 48 hours after endotracheal intubation
What are the possible causes of HAP/VAP?
- MRSA
- Pseudomonas
- Acinetobacter
- Klebsiella pneumoniae
What antimicrobial do you use for MRSA?
- Vancomycin
- Linezolid
- Avoid Daptomycin because it is inactivated by surfactant
What antimicrobials do you use for pseudomonas?
- Penicillin derivates: Piperacillin-Tazobactam
- Cephalosporins: Cefepime, Ceftazidime
- Carbapenems: Meropenem, Imipenem (NOT Ertapenem)
- Fluoroquinolones: Ciprofloxacin, Levofloxacin (NOT Moxifloxacin)
- Aminoglycosides (not used as first line due to toxicity: ototoxicity, nephrotoxicity, neurotoxicity): Amikacin, Tobramycin
- Questionable whether double coverage is needed but is often used in empiric regimens when there is worry about inadequate coverage with one agent (esp if antibiogram raises concerns)
What antimicrobials do you use for Acinetobacter?
- Carbapenems: Meropenem, Imipenem
- Often not that big of a concern and we do not always empirically cover (as we do for Pseudomonas)
- Some antipseudomonal drugs like these two carbapenems cover both Pseudomonas and Acinetobacter
What antimicrobials do you use for Klebsiella pneumoniae?
- Many drugs potentially active except for Ampicillin (Klebsiella is inherently resistant to Ampicillin)
- Ceftriaxone
- Cefotaxime
- All Pseudomonal drugs will also cover
What are some tests you would order for a patient with pneumonia?
- CBC
- metabolic panel (creatinine, LFTs)
- blood cultures x 2
- sputum cultures (if able to give good sputum sample)
- Pneumococcal urine Ag
- Legionella Ag (+/-)
- Influenza swab (depending on season)
- Chest X ray
What are the CURB 65 criteria?
Criteria to decide whether to admit a patient:
- Confusion
- Urea (elevated BUN)
- Respiratory rate (>30 breaths/minute)
- Blood pressure (90/60 or less)
- 65 years or older
What are the possible causes of pharyngitis?
- Group A Strep
- Fusobacterium necrophorum
- Neisseria gonorrhea
What antimicrobials do you use for group A strep pharyngitis?
- Penicillin or Amoxicillin x 10 days
- Treat if symptoms fit Strep pyogenes picture (use of rapid Strep Ag +/- throat culture) AND Centor’s criteria too
What are the CENTOR criteria?
A method to quickly diagnose the presence of Group A streptococcal infection or diagnosis of streptococcal pharyngitis:
- Cough absent
- Exudate or swelling on tonsils
- Nodes (Tender/swollen anterior cervical lymph nodes)
- Temp (fever >38°C/100.4°F)
- OR (young OR old modifier)
What antimicrobials do you use for Fusobacterium necrophorum pharyngitis?
- Amoxicillin/Clavulanic acid
- Rare but a distinct syndrome association (Lemierre syndrome – suppurative phlebitis of internal jugular vein as a complication of pharyngitis)
What antimicrobials do you use for Neisseria gonorrhea?
- Ceftriaxone plus Azithromycin
- Before treatement, testing done given specific sexual history
What is the common cause of Epiglottitis?
- H influenzae B
- Rare these days given Hib vaccination (may see it if parents have not been consenting to vaccines for their kids)
What antimicrobials do you use for epiglottitis?
- Ampicillin/Sulbactam
- Ceftriaxone
- Cefotaxime
- Most of these drugs are only in IV form (none of these are available in oral form) – we are worried about airway in these patients, we are not going to give them oral Abx
