Post on 28-Jan-2016
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Respiratory tract infection
By Dr.Preaw(General medicine )
Scope
Diagnosis : CAP , HCAP , VAP
Pathophysiology
Investigation
Management and treatment
Community-acquired pneumonia (CAP)
Diagnosis
1. Temperature > 38 ºC
2. Purulent secretion
3. Leucocytosis or leucopenia
IDSA/ATS Guidelines for CAP in Adults • CID 2007:44 (Suppl 2)
Moderate recommendation; level III evidence.
Pathophysiological modes of spreading
Aerosols inhalation Mycoplasma pneumoniae Chlamydophila psittaci Chlamydophila pneumoniae Legionella pneumophila
Orophryngeal secretions Streptococcus pneumoniae
Aspiration Haemophilus influenzae anaerobes , gram- negative bacilli
Hematogenous spread Staphylococcus aureus
Reactivation of latent Mycobacterium tuberculosismicroorganism Pneumocystis jirovecci
Mechanism Example
Pathophysiology :Failure of defences mechanisms
1. Alteration of normal oropharyngeal flora.
2. Depressed Cough and glottis reflexes.
3. Altered consciousness.
4. Impaired mucociliary apparatus mechanism.
5.Alveolar macrophage dysfunction.
6. Immune dysfunction.
Classification of pneumonia (based on anatomical part )
Bronchopneumonia : terminal bronchiole ( patchy consolidation)-Streptococci-Staphylococcus aureus-B Haemolytic streptocci-Haemophilus influenzae-Klebsiella pneumonia-Pseudomonas
Lobar pneumonia -Streptococci pneumoniae-Staphylococcus aureus-B Haemolytic streptocci
Interstitialpneumonia : without alveolar exudates-virus: Respiratory syncytial virus Influenza virus Adenoviruses Cytomegaloviruses-Mycoplasma pneumoniae
Pathologic Stages of Pneumococcal Lobar Pneumonia
Stage onset Affected lobe
congestion 1-2 day-proteinaceous fluid -neutrophils and many bacteria in aveoli
red hepatisation 2-4 day -red, firm and liver like consistency-proteinaceous fluid -> fibrin strands
gray hepatisation 4-7 day
-dry,firm and gray (lysed red cells)-neutrophils and bacteria also reduces-macrophages are seen
resolution over 3 wk( in normal )
-fibrinous matter
-macrophage ( major cells)
Criteria for severe community-acquired pneumonia.
confusion /disorentation
V/S RR> 30/min ,T < 36 ºC , hypotension
multilobar infiltration
Lab : BUN > 20 mg/dL , WBC < 4,000 cells/mm3 , platelet count <100,000 cells/mm3
PaO2/FiO2 ratio > 250
Minor criteria
Major criteria
Investigation and management
Evidence level Definition
Level I (high) well-conducted,RCT
Level II ( moderate)well -designed,controlled trials without
randomization
Level III ( low) case studies and expert opinion
Diagnosis testing remain controversial
InvestigationModerate
recommendation
hemocultureOPD case :level IIIIPD case : level I
sputum gram stain and culture level II
urine antigen for Legionella pneumophila and streptococcus pneumoniae level II
chest x ray level III
Sensitivity 69%false negative
1.dehydration2. early onset of PCP3. neutropenic patient
sensitivity 15-100%specificity 11-100%Adequate sputum PMN >25 cells/LPF
epithelium < 10 cells/LPF
sensitivity 70-90 %specificity 99 %
Classification of pneumonia (based on anatomical part )
Lobar pneumonia
Bronchopneumonia
Interstitial pneumonia
Gram : positive dipplococci :Streptococcus pneumoniae
Gram : negative bacilli
Management and treatment :hospital admission decision
CURB -65 score
strong recommendation :level I evidence
PSI score
Stratification of risk score
risk risk class score mortality
low Ibased on algorithm
0.1%
outpatient treatment
low II <70 0.6%
low III 71-90 0.9%
moderate IV 91-130 9.3%hospital
admissionhigh V >130 27%
PSI score
CURB-65 Treatment PSI scores Treatment
012345
OPDOPDIPDICUICUICU
-IIIIIIIVV
-OPDOPD
observe or hospitalizationIPDIPD
Summary
PIRO score for CAP
Factor Point Scores Risk
P
COPD or immunosuppresive 1
0-2low risk (1 in 30 )for ICU
mortalityAge > 70 yr 1
I
bacteremia
13
Mild risk (1 in 8) for ICU mortality
multilobar opacity 1
R
shock1
4high risk ( 2 in 5) for ICU
mortalitysevere hypoxia 1
O
ARDS1
5-8very high risk (3 in 4)
for ICU mortalityacute renal failure
1
Predisposition
Insult
Response
Organ dysfunction
ICU case
Management
Management : outpatient
setting antibiotic drugs recommendation
previous healthy (no use ABO in 3 month)
macrolide ordoxycycline
level I(strong)level III(weak)
comorbiditiesimmunosuppressing
conditon
respiratory fluoroquinolone orB-lactam +macrolide
level I(strong)level I(strong)
region with high rate (>25%)infection with high level ( MIC>16
mcg/ml)macrolide-resist streptococcus pneumoniae
ceftriaxone, cefuroxime doxycycline
level II (moderate)
C.pneumoniae (29%)M.pneumoniae(20%)S.pneumoniae(8%)
unknown (30%)
Management : inpatient
setting antibiotic drugs recommendation
non-ICU-respiratory quinolone or-B -lactam+macrolide or level I
ICU -B-lactam +azithromycin -respiratory quinolone
level IIlevel I (penicillin allergic patient)
levofloxacin,moxifloxacin ,gemifloxacin
cefotaxime , ceftriaxone,ampicillin-sulbactam
-gram negative bacilli(20%)-S.pneumoniae(19%)-C.pneumoniae(19%)-M.pneuminiae(9%)
-unknown (31%)
-S.pneumoniae(24%)-gram negative bacilli(20%)-
C.pneumoniae(15%)-unknown (31%)
Special condition
special concerns antibiotic drugs recommedation
Pseudomonas
-B-lactam+ ciprofloxacin or levofloxacin or
-B-lactam +aminoglycoside+azithromycin or
-B-lactam +aminoglycoside+fluoroquinolone
level III(moderate)
*CA-MRSA add vancomycin or linezolidlevel III
(moderate)
*CA-MRSA:community-acquired methicillin-resistant staphylococcus aureus
piperacillin-tazobactamcefepime,imipenem
meropenem
Criteria for clinical stability
Temperature < 37.8 ºCHeart rate < 100 beats/minRespiratory rate < 24 breaths/minSystolic blood pressure > 90 mmHgAterial oxygen saturation > 90 % or PaO2 > 60 mmHg on RAAbility to maintain oral intakeNormal mental status
Hospital-acquired pneumonia(HAP) :definition Presence of new chest X-ray infiltration plus one of the three clinical variables-fever > 38 ºC-leukocytosis or leukopenia (WBC >12,000 cells/mm3 or < 4,000 cells/mm3 )-purulent secretionsPneumonia that occurs 48 hours or more after admission
●
●
Ventilator-associated pneumonia : definition
Pneumonia that occurs 48 hours or more after intubation of endotracheal tube until 48 hours after extubation
Definition:HAP, VAP, HCAP
Healthcare-associated pneumonia(HCAP)
- Any patient who was hospitalized in acute care hospital for > 2 days within
90 days of the infection
- Resided in a nursing home or long-term care facility
- Received recent IV antibiotic therapy, chemotherapy or wound care within
the past 30 days of the current infection
- Attended a hospital or hemodialysis clinic
Hospital-acquired pneumonia(HAP)
Early onset pneumonia (within < 4 days of hospital admission)pathogens -> S.aureus -> S.pneumoniae -> H.influenzae
Late onset pneumonia ( > 4days of hospital admission)pathogens ->MRSA ->drug-resistant GNEB ->P.aeruginosa ->A.baumannii
HAP : pathogenesis
-Microaspiration:from oropharynx to lungs-Aspiration from stomach to lungs-Colonization of ET tube with bacteria encased in biofilm result into alveoli during suctioning or bronchoscope-Inhalation of pathogens form contaminated aerosols direct inoculation -Hematogenous spread
Risk factor for multidrug-resistant pathogens causing
HAP, HCAP, VAP
-Antimicrobial therapy in preceding 90 days-Current hospitalization of 5 days or more-High frequency of antibiotic resistance in the community or in the specific hospital unit-Presence of risk factor for HCAP Hospitalization for 2 days or more in preceding 90 days Residence in a nursing home or extended care facility Home infusion therapy ( including antibiotics) Chronic dialysis within 30 days Home wound care Family member with multidrug- resistant pathogen-Immunosuppressive disease and/or therapy
Assessment of nonresponders
wrong organismdrug-resistant pathogeninadequate antimicrobial
therapy
wrong diagnosisARDS
atelectasispulmonary emboli
pulmonary hemorrhageneoplasm
underlying disease
complicationempyema or lung abcess
Clostridium difficile coliitisoccult infection
drug fever
Summary
Diagnosis :
CAP
HCAP
VAP
Summary
CURB-65
PSI score
PIRO score
Summary
-Management-Prevention-Accessment of nonresponder