Pneumonia Flashcards
List common causative organisms of pneumonia for
Typical
- strep pneumo +ve cocci
- H. influenzae -ve rod ( common in COPD, ETOH, malnutrition, malignancy or t2dm)
- staph aureas ( often associated with influenza superinfection)
- moraxcella catarrhalis
Atypical - legionella -mycoplasma ( most common causes of CAP in previously well patients under 40) -chlamydia Coxiella burnetti
HAP
- -ve bascilli (pseudomonas, enterobacteriaceae, klebsiella, acinetobacter)
- +ve cocci (S.aureuas including MRSA)
Aspiration ( generally poly microbial)
- peptopstreptococcus
- bacteroides
- fusobacterium
- prevotella
Viral
- RSV
- parainfluenzae
- flu a and b
- CMV<
Fungal
- histoplasma capsulatum
- blastomyces dermatitidis
- coccidioiddes immitis
TB
Define HAP and VAp
HAP- occurs 48 hours or more after admission and does not appear to be incubating at time of admission ]
VAP - occurs 48-72 hours after ETT
Discuss chemical aspiration
IF story convincing for aspiration pneumonitis antibiotics are not indicated– if devleops signs of bacterial pneumonia including new fever expanding infiltrate appearing at more than 36 hours should treat as aspiration pneumonia ]
Chemical aspiration disrupts surfactant and causes and an inflammatory response that may lead to hypoxia or respiratory failure `
Discuss the CXR in pneumonia
Pyogenic bacterial pneumonias generally show an area of segmental or subsegmental infiltration with air bronchograms
Few bcaterial pneumonias have a full lobar pneumonia most often caused by Klebsiella – lobar pneumonia with a buldging fissue is classical
Atypical pneumonia will lead to fluffy or patchy infiltrates in the involved region of the lungs
Bilateral intersititial infiltrates starting in the perihilar region are classical of PCP
Aspiration pneumonia occurs in the depedent areas of the lung usually the superior segments of the lower lobes or posterior segments of the upper lobes
Infiltrates from pneumonias produced by haematogenous spread ( s aurea) tend to be multiple and peripheral.
Discuss procalcitonin use in pneumonia
Has been used as a means to assess the likelihood of a bacterial cause response to antimicrobial therapy and prognosis.
Can slightly reduce antibiotic use without increased morbidity
Discuss parapneumonic effusion – indication for thoracentesis
If greater than 5 cm on CXR should have thoracentesis this should be sent for cell count, differential, ph (PH <7.2 predicts need for thoracostomy tube), gram stain, culture, LDH and protein
Discuss lights criteria
Transudate:
- Protein (PF/serum) <0.5
- LDH (PF/serum) <0.6 , pleural LDH < two thirds upper limits of normal serum LDH
Exudate
- Protein (PF/serum) >0.5
- LDH (PF/serum) >0.6 , pleural LDH > two thirds upper limits of normal serum LDH
Can send for cholesterol, TGL, glucose creatinen, ph
PH of normal pleural fluid is 7.6 – more acidic can be seen when pleural fluid cells and bacteria increase acid production (empyema) or with decrease H efflux due to pleuritis tumour or pleural fibrosis. Malignancy common cause of this
Discuss serological testing for pneumonira
Serological testing is available for c. pneumonia, legionella and fungii.
Urine antigen test for s.pneumonia and legionella are also available
Discuss management of pneumonia
Mild CAP - B lactam agent alone
Moderate cap - benpen and doxy/azithryomycin
Severe CAP - ceftriaxone and azithryomycin + vanc (MRSA) + gent if significant risk of gram-ve
Aspiration - anerobic activitiy addition of metronidazole or clindamycin – or use antibiotics with anaerobic activity such as piptaz, ertapenem, moxiflox
HAP - mild ceftriaxone
Moderate/severe- piptaz
AIDS – addition of bactrim to cover PCJ 15/75mg/kg for 21 days
In patient with severe pneumonia and hypoxemia addition of steroids prednisone/hydrocort has been shown to reduce mortality
Discuss the pneumonia severity index
Score taking into account demopgraphic factors, comorbidities, physical exam and lab/radiographer to assess risk of severity - estimates mortality for inpatients
Demographics (4) Age -Male ( age in years = points) -Female ( age in years -10 = points ) nursing home resident 10 points
Cormorbid illness (5)
- neoplastic 30
- liver 20
- CCF -10
- Cerebrovascular disease - 10
- renal disease - 10
Exam (5) - Altered mental status 20 -RR >30 - 20 BP >90 - 20 - T <35 or >40 - 15 -HR 125 - 10
Labs (7) - Art ph <7.35 - 30 Urea >7- 20 NA <130 - 20 Glucose > 14 Haematocrit <30% Art Po2 <60mmhg Pleural effusion 10
Risk
III Low 71-90
IV Moderate 91-130
V High >130 total points
Discuss CURB 65
Confusion Uremia >7 RR >30 BP >95 AGe 65
Risk of 30 day mortality
0.7% with 0
9.2% with 2
57% with 5
Discuss smartcop
Predicts the need for intesive respiratory or vasopressor support
Age - BP >90 Multilobar chest involvement Albumin <3.5 RR >30 HR >125 Confusion PF ratio<250or pao2 <60 Ph <7.35
List a infectious differential for cavitary lung lesions
Infections
-Anaerobic bacteria - often mixed with aerobic
-Other bacteria (staph, klebsiella pneumonia, enterobacteriaceae, pseudomonas, legionella, Burkholderia pseudomallei (melliodosis)
-Mycobacterai
Mycobacterium tuberculosis
-Fungi asperigillus coccidoides histoplasma crytpococcus PCP
Parasites
- entameoba histolytica
- paragonimus westermain
Empyema with air fluid level
septic pulmonary emboli
List non infectious differential for cavitary lung lesions
CAVITY
Neoplastic
- adenocarcinoma
- Mets
Autoimmune
-Vasculitits (granulomatosis with polyangitis)
Rheumatoid noduls
Sarcoidosis
Vascular
-Pulmonary embolism with infarct
Infection – see previous
Trauma
-pneumatocele
Young-
Sequestration
-CPAM
Discuss antibiotic choice for HAP
If not at increased risk of gram -ve infection (e.g structural lung disease (bronchiectasis or cystic fibrosis) or a respiratory grame stain with numerous and predominant gram -ve bacilli) and not at risk fo MRSA can use the followin
- Piptaz 4.5 Gram QID
- -Cef 2G IV BD
- -Levofloxacin 750mg IV daily
If at risk of MRSA add vancomycin 20-35mg/kg loading and interval dosing determined by nomogram
If at increased risk fo gram -ve infection or confirmed use one of followin
Piptaz 4.5 QID
Cefepime 2G IV TDS
Meropenum 1G IV TDS
Plus, Gentamicin 5-7mg/kg and if at risk of MRSA add vancomycin as above
