CAP Flashcards
what is the pathogenensis of pneumonia? (3 mechs)
- aspiration of oropharyngeal secretions
- inhalation of aerosols (containing bac)
- hematogenous spreading (bac inside blood, carry to lungs–> bac replicate in lungs–> pneumonia, bacteremia from extra pulmn source)
s/sx of pneumonia
- cough, chest pain
- SOB, hypoxia
- fever >38C, chills, fatigue, anorexia
- tachypnea, tachcardia, hypotension
- leukocytosis
what physical examination is done to assess pneumonia
- diminished breath sounds over affected area
- inspiratory crackles during lung expansion
pneumonia lab findings
eg. C reactive protein, procalcitonin
- non specific
- limited discriminatory potential
- not rec for routine use
what resp cultures are taken ? (2)
- sputum culture
- low yield (may not be able to identify bac that is causing pneumonia), freq contamination by oropharyngeal secretion
- quality sample: >10 neutrophils (indicate infection) AND <25 epithelial cells (less contam by motuh flora) per low power field - lower resp tract sample
- less contamination
- invasive sampling
Why are blood cultures taken for pneumonia
to eliminate bacteremia
what org does urine antigen test identify?
- strep pneumoniae
- legionella pneumophilia
limitations of urien antigen test?
- indicate exposure to respective pathogen (pt exposed to pathogen but doesnt mean it caused the pneumonia)
- remain positive for days-weeks despite ab tx
not routinely used
define hospital acquired ppneumonia HAP
onset >=48 h after hospital admin
define ventilator assc pneumonia
onset >48h after mechinical ventilation
define community acquired pneumonia CAP
onset in community or <48h after hospital admin
what are the 3 classificatiosn of pneumonia
hospital acquired
ventilator assc
community acquried
risk factors for CAP
age>65
previosu hospitalisation for CAP
smoking
COPD, DM, HF, cancer, immunosup
how to prevent CAP
smoking cessation, immunisation (influenza, pneumococcal)
how does severity of CAP determine tx (4)
- location of tx
- org that need to be covered
- empiric ab selection
- ROA of ab
criterion for CAP risk stratification (CURB-65)
- confusion
- urea > 7mmol/L
- RR >39 breaths/min
- Blood pressure (sbp<90, dbp<60)
- age >65
if the total score is 0 or 1: outpat
score 2: inpatient
score >=3: inpt, consider ICU
what are teh moajor criterias for severe CAP
- mech ventilation
- septic shock vasoactive medications
minor criterias for severe cap?
- RR>30
- hypoxia, paO2>250
- multilobar infiltrates
- confusion
- uremia (urea>7mmol/L)
- leukopenia (WBC<4x10^9
- hypothermia (core tmpe<36)
- hypotension req aggressive fluid resuscitation
what is criterias do we need to diagnose for severe CAP?
> =1 major
or
=3 minor
what are the potential org to cover for OUTpt
- strep pneumo
- haemophilus influenzae
- atypical org
what is the empiric therapy for generally healthy outpt
- beta lactam (amoxicillin)
or
resp FQ eg. levo or moxifloxacin`
what is the empiric therapy for pt pop with chronic heart, lung, liver renal disease, DM.. outpt
need to cover atypical as well
1. beta lactam (amox/clav) pr cefuroxime PLUS macrolide (clarithromycin or azithromycin) or resp FQ (levo/moxi)
what is the standard regimen for inpatient non severe
- beta lactam (amox/clav or ceftriazone) PLUS macroldie (clarithromycin or azithromycin)
or resp FQ (levo/moxi)
ROA of inpt non severe?
beta lac and FQ admin IV- step down to PO when pt imrpoves
macrolide and doxycycline PO
what is the regimen for inpatient severe?
1. beta lactam (pen G or amox/clav PLUS ceftrazidime) plus 2. macrolide or doxycycline OR resp FQ (levo/moxi) PLUS ceftazidime (to cover burkholderia)
what organisms to cover for inpt severe?
- strep pneumo
- H flu
- atypical org
- s aureus
- other gram neg bacilli
when to cover anaerobic? what indications? (2)
- lung abscesss
- empyema (abscess in lung pleural space)
what ab to add when standard regimen has no anaerobic cov?
clindamycin IV/PO
metronidazole IV/PO
what indications to cover for MRSA? (2)
- prior respiratory isolation of MRSA in last 1 year
- severe CAP only, hospitalisation and received IB ab within last 90 days and locally validated risk factors (look at antibiogram to check which MRSA is common)
what ab to add wto cover MRSA? (2)
vancomycin IV
linezolid IV/PO
what indicatiosn to cover for pseudomonas?
prior resp isolation of ps. aeruginosa in last 1 year
how to modify standard regimen to cover ps/
include pip/tazo IV, or ceftazidime IV or cefepime IV or meropenem IV or levofloxacin IV/PO
Why dont we use resp FQ as first line for CAP
- many adverse effects eg. tendonitis, tendon rupture, neuropathy, qtc prolongation, cns disturbances, hypoglycemia
- dev of resistance with overuse
- preserve activity for other gram neg infections– its the only PO option to cover pseudomonas, dw to anyhow use
- delay diagnosis of tb
why is adjunctive coritcosteroid therapy considered for soem pt?
- less inflammation in the lungs
- variable drug and dosing regimens
- may reduce length of stay and tiem to clinical stability
- NOT ROUTINELY REC
how to monitor safety of therapy?
- adverse effects eg. diarrhea, rash
- renal func
hwo to monitor efficacy of therapy?
- clinical improvemnt expecte din 48-72h
- less cough, chest pain, SOB, fever, wbc
- elderly pt or those with multiple co-morbs may take longer
- should not escalate ab therapy in the first 72h (unless culture directed or significant clinical deterioration)
- rediographic improvement lags behind (4-6 weeks for reso)- repeat only if clnical deterioration eg. chest xray
when to stop empiric cov for MRSA or ps. aeruginosa?
- may be stopped in 48h if no mRSA or ps is foun din culture AND pt is improving
when can IV ab be stepped down to PO?
- hemodynamically stable
- clinically improved
- aferbile >24 h
- able to ingest PO med
- normally functioning GIT
what are the general benefits of IV to PO? (5)
-
- higher pt comfort and mobility
- less risk of nosocomial axquired bloodtream infection
- less phlebitis
- decreased prep and admin time
- lower cost
- facilitates discharge
what is the tx duration ?
until clinical stability is achieved and for at elast 5 days
- most achieve clinical stab in 48-72h
exceptions
- MRSA, ps: 7 days
- burkholderia: 3-6months
what is considered clincal stable?
- afebrile, able to maintain oral intake, normal vital signs, o2 saturation and mental status
