Transcript infection in A&E

Infections in Accident and emergency
Philip G. Murphy
Consultant in Medical Microbiology, AMNCH
Clinical Professor, TCD
Tel. ext. 3919
[email protected]
Lecture objectives
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Integrate Microbiology knowledge to A&E Doctor
Consider factors unique to A & E dept Vs GP
Emergency infections
Trauma infection eg tetanus
Systematic approach to A & E infection
Ix and Dx clinical Vs empirical
Others: tourist fever, bites, sharps, infection control
Is an antibiotic indicated ?
Unique factors in A&E
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Concerned patient/parent ?? Need admission
Interface of community and hospital
Gatekeeper of all inpatient admission
Under-resourced in IRL
Over usage Vs GP.
GP 2nd opinion
Triage
Emergency Infections
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Meningitis (Pen access)
Bacteraemia / septicaemia
Endocarditis
Osteomyelitis
Otherwise minor infection in
Immunsuppressed eg varicella
Meningococcal petechiae
purpura & DIC (bleeding NG)
septicaemia
Fresh splinter haemorrhage
Meningitis
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Bacterial: N. Men ABC, pneumococcus, Hib, E coli, List.
Viral: Enterovirus group, Herpes
Hx: prodrome, contact
Dx: Meningism, fever, rash
Ix: CT. CSF and blood C&S, PCR
Rx: Ceftriaxone, pen
Px: ?who, rifampicin 600mg bd 2 days
Public Health
What is Shock?
• A physiologic state characterised by
– Decrease in tissue perfusion
– Inadequate oxygen delivery
• Delivery isn’t keeping up with demand
• May be bacterial: LPS, toxin
Gram negative – E. coli
Gram Positive - Staphylococcus aureus
What is SIRS?
The systemic inflammatory response
syndrome is systemic level of acute
inflammation, that may or may not be due to
infection, and is generally manifested as a
combination of vital sign abnormalities
including fever or hypothermia, tachycardia,
and tachypnoea.
Risk Factors for SIRS/Sepsis
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Extremes of age
Indwelling lines/catheters
Immunocompromised states
Malnutrition
Alcoholism
Malignancy
Diabetes
Cirrhosis
Male sex
Genetic predisposition?
The Continuum of Sepsis
SIRS Sepsis Severe Sepsis Septic Shock
Systemic Inflammatory Response Syndrome
SIRS criteria-must have 2 or more of the following:
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Temp < 36 ° C or > 38 ° C
HR > 90
RR > 20 or PCO2 < 4.3
WBC < 4 or > 12 or immature bands > 10%
Bone et al. Chest 1992;101:1644
The Continuum of Sepsis
SIRS Sepsis Severe Sepsis Septic Shock
Sepsis =
• Suspected or confirmed
infection
• 2 or more SIRS criteria
Bone et al. Chest 1992;101:1644;
Balk, RA
The Continuum of Sepsis
SIRS
Sepsis Severe Sepsis Septic Shock
Sepsis plus Organ Dysfunction
• Elevated Creatinine
• Elevated INR. Hyperbili
• Altered Mental Status
• Elevated Lactate >4
• Hypotension that responds to fluid
Bone et al. Chest 1992;101:1644
The Continuum of Sepsis
SIRS
Sepsis Severe Sepsis Septic Shock
Severe Sepsis and Hypotension
(SBP < 90mmHg)
• Hypotension that does NOT
respond to fluid (30 mls/kg bolus)
Bone et al. Chest 1992;101:1644
Septic Shock
• Combination
– Distributive
– Cardiogenic
– Hypovolaemic
• Most common form of Shock
• On a continuum from SIRS to Septic Shock
Why so Important?
Mortality of Severe Sepsis
250,000
Deaths/Year
200,000
150,000
100,000
50,000
0
AIDS*
†National
Breast
Cancer§
AMI†
Severe
Sepsis‡
Center for Health Statistics, 2001. §American Cancer Society, 2001.
*American Heart Association. 2000. ‡Angus DC et al. Crit Care Med. 2001 .
Shock: antibiotic Mx
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Bactericidal not bacteriostatic
Rapid kill without LPS release eg gentamicin
Broad cover and de-escalate later in recovery
Beta lactam + aminoglycoside
+/- ano2 (metronidazole)
+/- glycopeptide (vancomycin)
System review focus
Why so important?
•Overall mortality from SIRS/sepsis is approx.
20%.
•Mortality is roughly linearly related to the
number of organ failures, with each additional
organ failure raising the mortality rate by 15%.
•Hypothermia is one of the worst prognostic
signs. Patients presenting with SIRS and
hypothermia have an overall mortality of ~80%.
Factors influencing prescribing
Choice
Organism susceptibility
Concurrent therapy
Drug rep pressure
Patient pressure
Policies
Prophylaxis
Drug familiarity:
Dosage / cost
Toxicity / kinetics
Bioavailability
Best guess susceptibility
Patient immune state
Nature of infection
Patient physiology
Allergy history
Breast feeding
Pregnancy
Age
Compliance
Social/work issues
Trauma infection
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Wound management
Compound or closed
Dirty e.g., Tetanus
cSSI e.g.,Cellulitis
Cellulitis
• 90% Haemolytic Streptococci
• 10% Staphylococci
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Culture if skin broken
Rx Penicillin + Flucloxacillin
Increase dose until erythema controlled
Monitor CRP
2nd line Clindamycin
Beware necrotising fasciitis
Tetanus prevention
Clostridium tetanus toxin = neuromuscular toxin
S+S: muscle spasm near wound, later generalised, lockjaw
Rx: Ig, vaccine, antibiotic
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Type of woundClean (Low Risk)
Clean incised wound
Superficial graze
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Scald
Tetanus Prone (High Risk)
Any wound or burn > 6 hours old
Any wound with one or more of
the following:
Contact with soil, manure, compost
Puncture type wound
Infected wound
Compound fracture
Wound containing foreign bodies
Large amount of devitalised tissue
Animal or human bite
Risk assessment of wounds for use of tetanus
immunoglobulin (TIG)
Age
Immunisation status
Clean wound
Tetanus prone wound
<4 y
<3 doses or unknown
3 or more doses
DTaP/IPV+/-Hib
Nil
TIG, DTaP/IPV +/- Hib
Nil Consider TIG
>4 to 9y
<3 doses or unknown
3 doses only, >5 years
since last dose
3 or more doses, <5 years
since last tetanus toxoid
4 or more doses, >5 years
since last dose
DTaP/IPV
TIG plus DTaP/IPV
DTaP/IPV
DTaP/IPVConsider TIG
Nil
Nil Consider TIG
Nil
DTaP/IPV, consider TIG
<3 doses or unknown
3 or more doses >10 years
since last dose
3 or more doses, <10 years
since last dose
Td
TIG plus Td/IPV
Td
Td, consider TIG
Nil
Consider TIG
>10 y
www.immunisation.ie
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? Antibiotic
Use a system approach
URT
LRT
70% of antibiotic prescriptions
SST
GUT- STD
CVS
Shock emergency
CNS
meningitis emergency
GIT
diarrhoea
Common viral: HS, VZ
Others: tropical parasites, Toxoplasmosis etc
Post-op hospital & minor ops.
Primary care
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80% of all antibiotics
80% respiratory tract indications
>50% still probably unnecessary
Cough probably the commonest acute single
reason for consulting (130 per 1000 patients
per year)
LRTI
Etiologic determinants for pneumonia
Host characteristics
Age
Multi-lobar Pneumococcal State of health
Immunocompetence
Bronchial pneumococcal
Environmental exposure
Geographic location
Community acquired vs nosocomial
Closed population settings (daycare centers,
military camps, nursing homes)
Unusual exposures (eg, animals)
Pathogen characteristics
Virulence
Inoculum size
Diffuse alveolar Influenzae
Apical TB
Community Acquired
Pneumonia
• Epidemiology:
– Incidence 3/1000
– Mortality 2-30%
• <1% for those not requiring hospitalisation
– fewest cases in 18-24 yr group
– probably highest incidence in <5 and >65 yrs
– mortality disproportionately high in >65 yrs
Community Acquired Pneumonia
Mortality
80
74.9
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# in 40
1000s 30
# of deaths
20
10
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5.7
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<4
5 to 14 15-24
25-44
45-64
>65
Community Acquired
Pneumonia
• Risk Factors for pneumonia
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age
alcoholism
smoking
asthma
immunosuppression
institutionalisation
COPD
PVD
dementia
ID Clinics 1998;12:723.
Am J Med 1994;96:313
Community Acquired
Pneumonia
• Laboratory Tests:
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CXR
FBC with differential
U+E
glucose
LFTs
Sputum culture
Blood culture
oxygen saturation
Urinary antigen: pneumococcus or Legionella
Community Acquired
Pneumonia
Diagnostic Evaluation
• CXR
– usually needed to establish diagnosis
– prognostic indicator
– rule out other disorders
– may help in etiological diagnosis
• Only 3% of outpatients and 28% of ED patients with
suggestive signs and symptoms actually have
pneumonia
J Chr Dis 1984;37:215-25
CURB-65:
Confusion (8 or less on AMT)
Urea > 7
Resp Rate > 30
BP (< 90/60)
Age > 65
Score:
0-1
2
3
Also useful:
BTS CAP guidelines: Thorax 2004
low risk (non severe - discharge)
increased risk (consider admission)
high risk (severe – admit)
Sats <92% or PaO2 <8 kPa
Bilateral disease
Age >50
Co-morbidity
CURB-65
Mortality
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0.7%
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3.2%
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13%
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17%
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41.5%
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57%
Microbial aetiology
• Haemophilus influenzae (3-10%)
• Streptococcus pneumoniae (20-60%)
• Moraxella catarrhalis
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Mycoplasma pneumoniae (1-6%)
Chlamydia pneumoniae (4-6%)
Chlamydia psittaci
Legionella pneumoniae (2-8%)
Coxiella burnetti
Viral (2-13%)
40-60%
No cause identified
2-5%
2 or more causes identified
Conventional
Atypical
Pneumococci Vs time since last antibiotic
(n =919 children)
60
sensitive
resistant
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40
30
20
48-52
40-47
32-39
24-31
16-23
15-Aug
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2-7 weeks
10
Hospital CAP Antibiotic strategy
• 1st line: Augmentin +/- macrolide (clarithromycin)
Moxifloxacin if pen allergic
• 2nd line: 3rd gen ceph +/- quinolone
eg., ceftriaxone +/- ciprofloxacin
Tourist Fever
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Think global - act local
Avian influenzae (H5N1)
SARS
Haemorrhagic fevers (Lassa, Ebola)
Legionella
Typhoid
Others
Avian flu
Acute onset of fever ( ≥ 38°C) with S & S of an acute respiratory infection.
AND At least one of the following exposures < 7 days prior to onset of symptoms:
Contact with poultry or wild birds
Reside in or have visited an area of a country where influenza A/H5N1 is currently
suspected or confirmed as reported in the HPSC web-site
http://www.ndsc.ie/hpsc/A-Z/Respiratory/AvianInfluenza/AffectedCountries/
Having been in close contact with sick or dead domestic poultry and/or wild birds
in an affected area;
or having been in a home or farm where sick or dead domestic poultry have been
reported in the previous six weeks in an affected area;
Human Contact: Having been in close contact (<1 metre) with a person reported
as a probable or confirmed case of influenza A/H5N1;
Laboratory Contact: Having worked in a laboratory where there is potential
exposure to influenza A/H5N1.
http://www.ndsc.ie/hpsc/AZ/Respiratory/AvianInfluenza/Guidance/File,2199,en.pdf
Inform Public Health infection control and Occupation Health.
Health care workers caring for cases of suspected A (H5N1) should be considered
for prophylaxis with oseltamivir (Tamiflu).
Avian influenza arrives in Paris
+ case definition
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Infection Control/ Isolation and Reporting
Strict hand hygiene.
Patient to be put into a side room in the ED
immediately.
Staff to wear respirator mask – minimum standard
FFP2, gown/plastic apron, gloves.
Patient to wear surgical mask.
Inform and consult with Infection Control prior to
moving or transferring patient (e.g. X ray).
Blood borne virus exposure
(eg needle stick)
• Risk assessment of wound & injury
• Wound toilet
• Hep B – vaccine if non immune
+/- HBIg if source positive
• Hep C - Monitor blood, LFT’s
• HIV – assess for PEP
Animal bites
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Dogs 80%
Cats 10%
Humans 5%
Others 5%
Basic wound Mx do not close (2o closure)
Antibiotics if deep Rx Augmentin
Rabies Rx Vaccine x 5 (+ Ig if high risk)
Infection Control
• Irish A&E departments inadequate
– isolation, toilet and washing facilities
• Attempt to isolate and cohort:
diarrhoea,TB., Norovirus
Lecture self assessment
Give examples for each
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How does A&E differ from 10 and 2o care
Emergency infections
Management of infected trauma
Other examples