Exam 3 lecture 1 Flashcards
Where do LRTI usually take place? Where does pneumonia usualy take place?
Trachea, bronchi, bronchules, alveoli
Alveoli most important because most pneumonia occurs.
What is the host defence mechanism for URT? LRT?
URT
1. Nasopharynx
-nasal hair
-IgA secretion
-Mucocilliary apparatus
-fibronectin
- Oropharynx
- saliva
-slough epithelial cells
-complement prodyction
LRT
3. Trachea/bronchi
- cough
-epiglottic reflex
- Anatomy of conducting airways
-Mucocilliary apparatus
-Immunoglobulin
- Alveolar lining fluid
cytokines
macrophages + PMN
cell mediated immunity
Define community acquired pneumonia
Pneumonia developed outside of the hospital or within the 1st 48hrs of hospital
What is the importance of CAP (community acquired pneumonia) (how common is it?, mortality?)
Most common cause of infection related hospitalization and mortality in the US
30 day mortality after hospitalization due to CAP is 2.8% for those <60 yo while about 26.8% for those 60 and above with comorbid conditions
What are ways CAP infection happen?
- Aspiration- most common pathway. Common for all individuals during sleep. Organism cleared if host defense is functioning properly.
- Aerosolization- Direct inhalation of pathogen. Primarily ciruses, bacteria and fungi. Droplet Nuclei, particles containing pathogen
- Bloodborne- Translocate to pulmonary site. Extremely unlikely
Most common organism that causes pneumonia
Virus
What are common bacterial pathogens
Strep pneumoniae
Haemophilus influenzae
Mycoplasma pneumoniae (atypical)
Legionella Pneumophila (atypical)
Chylamydia oneumonia (atypica)
Staph aureus
Where do we see the presence of strep pneumoniae?
Increased prevalence in patients that have immunocompromised states (chemo, transplant drugs)
Wha t are risk factors for drug resistance with strep pneumoniae
Age<6 or >65, prior antibiotic therapy, co morbid conditions, day care, recent hospitalization, close quarters (nirsing home, dorm)
Describe penicillin and macxrolide use with strep pneumoniae
penicillin- 3% resistance
Macrolide- 45-50%
Describe how mycoplasma pneumoniae is identified? spread?
Atypical bacteria- so will not show up on gram stain
Spread by person to person contact
How does mycoplasma pneumonia present at first? Symptoms? Imaging?
2-3 weel incubation period, followed by slow onset of symptoms
Persistent, non productive cough, fever, headache, sore throat, rhinorrhea, N/V, arthralgia
Imaging usually more pronounced with patchy, interstitial infiltrates
What type of bacteria is legionella pneumonophilia? How is it spread? Risk factors?
Atypical pathogen
spread by aerosolization
Increased risk: older males, chronic bronchitis, smokers, and immunocompromised
How is legionella pneumophilia characterized (sx/ss)
Multi system incolvement (fever, bradycardia, mental status change and increased LFTs + SCr)
Prevalence of staph aureus pneumonia? Risk factors for mRSA?
Low prevalence
RF
- 2-14 days post influenza
- previous MRSA infection/isolation
-Previous hospitalization
- Previous IV antibiotics use
What is important to do when dealing with staphylococcus aureus
Important to get MRSA nasal PCR
What are the most common pathogens with structural lung disease (cystic fibrosis, bronchiectasis)? Recent antibiotic exposure?
S. Aureus, P. aeruginosa
What is the classic presentation for CAP? For elderly patients?
Classic- sudden onset of fever, chills, pleuric chest pain, dyspnea, productive cough
- gradual onset with lower severity for mycoplasma pneumonniae and chylamidia
Elderly patients clinical presentation for CAP?
Classic symptoms may be absent (afebrile and mild leukocytosis)
- more likely to have decrease in functional status, weakness, and mental status changes
how to diagnose CAP?
-Chest radiography (recommended for all pts with suspicion for CAP)
What are some key words to look for in chest radiography that shows CAP? What type of infiltrates are seen in lung?
Dense lobar consolidation or infiltrates= suspicion for bacterial origin
Patchy, diffuse, interstitial infiltrates= atypical or viral pathogens
What are some microbiology testing methods for CAP
Tracheal aspiration
Bronchoscopy
Bronchoalveolar lavage (BAL)
What are markers we look at when looking for CAP
-WBC with differential
-Scr, BUN, electrolytes, LFTs
- Pulse oximetry, O2 sat
- Urinary antigen tests Tests for either
- S. pneumoniae
- Legionella pneumophilia
- Nasopharyngeal PCR swabs
-MRSA
- Viral swabs
When are cultures used?
Respiratory cultures or blood cultures are used for severe patients.
What is severe CAP? What are the criterias
Major criteria (we only need one)
- Septic shock requiring vasopressors
- Respiratory failure requiring mechanical ventilation
Minor (we need atleast 3)
-Resp rate > 30bpm
-multilobar infiltrates
- COnfusion/disorientation
-uremia (BUN 34)
- Leukopenia
-Thrombocytopenia
-Hypothermia
-Hypotension
What is a biomarker for CAP? WHen should and should it not be used?
Procalcitonin
elevated in presence of bacterial infection. SHOULD NOT be used to determine need for antibiotic for CAP
What are supportive measures for treatment of CAP
Humidified oxygen
Brinchodilators
Fluids
Chest physiotherapy
Empiric therapy for outpatient CAP WITHOUT comorbidities or risk factors for antibiotic resistance1
- Amoxicillin 1 gm PO Q8H
- Doxycycline 100 mg PO BID
- Macrolide resistance <25%, Azithromycin 500 mg PO on day 1, followed by 250 mg PO on day 2-5 (rare)
What are comorbidities that we look out for with patients with CAP
Chronic heart, lung or renal disease; diabetes mellitus; alcoholism; malignancy; asplenia or immunosuppression
Monotheraoy for Outpatient CAP? dose?
Respiratory fluoroquinolones (levafloxacin 750 mg PO daily, moxifloxacin 400 mg PO qd)
Combo therapy for outpatient CAP
preferred due to resistance and AE
Beta lactam + Macrolide (doxyxyxline if contraindicated)
What are beta lactams used in outpatient CAP? Dose?
AMoxicillin/clauvulanate 875/125 mg PO Q12H
Cefpodoxime 200 mg PO Q12H
- Cefuroxime 500 mg PO Q12H
What can we use to treat non severe inpatient CAP without MRSA/pseudomonas aeruginosa risk factors
Monotherapy- Respiratory fluoroquinolones (levo and moxi)
Combination therapy- Beta lactam + Macrolide
What are the B lactams recommended for non severe in patient CAP? What can be used if FQ or macrolide contraindicated?
Ampicillin/sulbactam
CEftriaxone
Doxy can be used if FQ or macrolide contraindicated
for severe in patient caps with no MRSA/pseudomonas risk factors what is tx
COmbination therapy- beta lactam + Macrolide (1st choice)
Combination therapy- Respiratory fluoroquinalone + Beta lactam
What B lactams are recommended
Ampicillin/sulbactam
Ceftriaxone
What can be a choice for severe in patient CAP with no MRSA/pseudomonas aeruginosa risk factors
Doxycycline
What are MRSA risk factors
-2-14 days post influenza
-Previous MRSA respiratory infection
- previous hospitalization and use of IV antibiotics within last 90 days
What can we utilize for MRSA coverage for in patient severe CAP
Vancomycin
Linezolid
What are Pseudomonas aeruginosa risk factors?
-Previous pseudomonas aeruginosa risk factors
- Previous hospitalization and use of IV antibiotics within last 90 days
What are antibiotics used for pseudomonas coverage
- piperacillin/tazobactam
-Cefepime
-Meropenem
When are corticosteroids not recommended
Only recommended with septic shock.
Not used for severe or non severe CAP
Duration of therapy for pneunmonia
5 total days.
Ensure clinical stability prior to dx antibiotics (temp, HR, RR, SBP, O2 sat, baseline mental status)
do we have to worry about anaerobic coverage for aspiration pneumonia?
Recommend against anaerobic coverage unless lung abscess or empyema present.
When should we stay away from fluoroquinolones
QT prolongation
Define HAP?
pneumonia occuring >48 hrs after hospital admission
Define VAP
(ventilator associated) Pneumonia occuring >48 hrs after endotracheal intubation
How does HAP take place? Is it usually gram positive or negative?
micro aspirations of oropharyngeal secretions that are colonized with bacteria.
Usually colonized with aerobic gram positive bacteria and converts to gram negative after 3-5 days of hospitalization
What are risk factors for HAP/VAP
Advanced age
severity of comorbid disease
Duration of hospitalization
ENdotracheal intubation
Nasogastric tube
Altered mental status
Surgery
Previous antimicrobial therapy
How to diagnose HAP/VAP
timing (48 hrs from admission)
Typical presentation (New lung infiltrate + Clinical signs and symptoms)
common pathogens for HAP
- aerobic gram negative bacilli= 70%
- pseudomonas aeruginosa= 10-20%
- Enteric gram negative bacilli = 20-40%
- Acinetobacter baumanii= 5-10% - S. aureus= 20-30%
- MRSA greater concern in this population
What are common microbiology testing used in HAP
-respiratory cultures (utilized for intubated pts)
-blood culture
What happens if we get invasive respiratory culture for HAP such as a BAL
we want to look at how much we are collecting.
We only have infection if BAL>10,000
risk factors for MDR for HAP? VAP?
- Multi-drug resistant (MDR) HAP
-prior IV antibiotic use within 90 days - MDR VAP
- prior IV antibioic use within 90 days
- septic shock at time of diagnosis
- Acute respiratory distress syndrome prior to diagnosis
- Acute renal replacement therapy prior to VAP onset
- >or= 5 days of hospitalization prior to diagnosis
What should empiric therapy for HAP
should be based on local antibiogram
When choosing empiric therapy for HAP, what are the risk factors for MRSA? WHat drugs to use
-ICUs where >10-20% MRSA isolates
-IV antibiotic within last 90 days
Vancomycin
Linezolid
For empiric therapy in HAP, what are risk factors for resistance when treating pseudomonas aeruginosa
ICUs where >10% of ioslates resistant
- treatment where resistance rates are unknown
For pseudomonas aeruginosa, what would we use to treat it for HAP?
-Piperacillin- tazobactam
-Cefepime
-Imipenem
-Meropenem
-Levofloxacin
What is the goal when treating patients with HAP with no risk of mortality? What are the requirements to be classed not high risk?
Goal- provide coverage for MSSA + Pseudomonas aeruginosa
Requirement- not on ventilatory support or septic shock
For not high risk mortality pts with HAP what would we use to treat
Piperacillin- tazobacta,
- cefepime
Imipenem
meropenem
levofloxacin
What is the goal for treating HAP not at risk for mortality but MRSA risk? What are antibiotics used for this?
Goal- Provide coverage for MRSA + Pseudomonas aeruginosa
Piperacillin- tazobactam
Cefepime
imipenem
meropenem
levofloxacin
(Pseudomonas)
+
Vanc
or linezolid (FOR MRSA)
What is the goal of treating high risk (On ventilator or septic shock) mortality and MRSA risk? What is antibiotic therapy?
Goal- provide coverage for MRSA+ MDR p. aeruginosa
Pick 2 different of these drugs for P. aeruginosa
- piperacillin-tazobactam
- Cefepime
- Imipenem
- Meropenem
- Levofloxacin
- Tobramycin/Amikacin
(SHOULD BE 1 betam lactam and 1 non beta lactam)
+
Vancomycin
Linezolid
When treating VAP, when do we choose 2 anti peudomonals? What are the antibiotics used for VAP?
- When we have risk factors for resistance ( Antibiotic IV, resiatance rate >10%)
Piperacillin-tazobactam
Cefepime
Imipenem
Meropenem
Levofloxacin
Tobramycin/amikacin
+
Vancomycin
Linezolid
What does daptomycn cover? What should we never do?
MRSA
SHould never be used for LRTI
What are aminoglycosides considerations
Recommend against use as monotherapy
Avoid empiric use unless necessary
Poor lung penetration, nephrotoxicity, ototoxicity,
What are considerations for polymixin
avoid empiric use
reserved for pts with HIGH MDR pathogens. SIgnificant nephrotoxicity
Tigecycline considerations
Associated with increased mortality, great for polymicrobial infections
recommended duration for HAP/VAP
7 day duration
When we get ESBL, what do we use
meropenem due to resistance to B lactamase
