Sepsis Flashcards
Define colonisation
The presence of a microbe in the human body without an inflammatory response
Define bacteraemia
The presence of viable bacteria in the blood
Define sepsis
Life threatening organ dysfunction caused by dysregulated host response to infection
Define septic shock
Subset of sepsis with circulatory and cellular/metabolic dysfunction associated with a higher risk of mortality
BP and Lactate paramters to define septic shock
Sepsis AND both of:
- Persistent hypotension requiring vasopressors to maintain Mean Arterial Pressure (MAP) greater than or equal to 65 mm Hg, AND
- Lactate greater than or equal to 2 mmol/l.
(despite adequate volume resuscitation)
What NEWS score likely means pt is resonding excessivey to infection?
5 or higher
Which people don’t repsond normally to infection?
Kids, elderly, pregnant, immunosuppressed, comorbid drugs, genetics, spinal cord injury
- use clinical judgement
When should you adjust up a pt’s NEWS score?
Clinical/carer concern
Deterioration
Surgically remediable sepsis (taking out abscess is better than antibios)
Neutropenia
Blood gas/ lab evidence organ dysfunction/lactate
Most common gm pos cocci source
Skin and soft tissues
Lines and devices
Most common gm neg bacilli source
Urinary
Gut
Biliary
Bug that is really sensitive to autolysis
Strep pneumoniae
- uses up all nutrients really quickly then population crashes and can’t detect bugs in culture bottles
Bugs v difficult to see on culture
Campylobacter
Legionella
Types of haemolysis
Alpha - incomplete
Beta - complete
Gamma - none
Why is it important to take cultures before giving antibios?
Much fewer pos cultures after antibios given
Where is CRP produced?
Liver
- normal range <10
- absent CRP due to hepatic failure e.g. does not mean low CRp
Why does PCT rise in infection?
Endotoxin and LPS produced by bacteria stimulates production of PCT which is excreted renally
- normal range ~0
High CRP and low PCT
Non-bacterial infection
Post surgical
Causes of gm neg sepsis
Escherichia coli,
- Klebsiella,Serratia, Acinetobacter, Enterobacter
Pseudomonas
Neisseria meningitidis
Neisseria gonorrhoea
Membrane of gm neg bacteria
cell envelope contains an additional outer membrane composed by phospholipids and lipopolysaccharides
- convey overall negatie charge
- pathogenicity is assoc with LPS layer
What are coliforms?
Pink rods existing as single bugs - no colony forming or clumping
What are ESBLs?
Extended Spectrum b-Lactamases
No response to penicillins, cephaosporins and aztreonam
Often have other resistance mutations and are spread via plasmid
- pts who get healthcare abroad often need rectal swab to determine if they have resistant bugs
Gentamicin protocol to minimise harm
Limit duration (72h then micro approvla)
Monitor renal function daily
Exclusion criteria
Nomogram when dose <1mg
Once only prescribing
Ref to ward pharmacist
Describe haemophilus influenzae
a gram-negative coccobacillus.
- aerobic but also facultative anaerobe
- grown on chocolate agar
- amoxicillin and doxycycline are active
Macrolides
-Mycin
Fluoroquinolones
-Floxacin
Managing atypical non-strep pneumonia
Doxycyline
(no kids or pregnant ppl)
Clarithromycin
Quinolones
(c diff risk)
Lower mortality than bacterial pneumonia, legionella is higher
How can legionella cause infection?
Live in lukewarm aerosolised water ( showers, air conditioning , taps)
Multiplies within amoebae and ciliated protozoa
Breathing in legionella causesinvasion and growth within alveolar macrophages
Pontiac fever is less severe disease
RFs for legionella infection
smokers, males, COPD, immunosuppressed, malignancy, diabetes, dialysis, hot tubs
Test to determine which type of cocci
Catalase test
+ staph
- strep
- entero
Coag pos and neg staph
+ staph aureus
- staph epi
Alpha and beta haemolytic strep
A - strep viridans, pneumoniae
B - group A-H strep
Management of staph aureus sepsis
IV fluclox
- IV vancomycin if allergic or MRSA
Management coag neg staph sepsis
Staph epi
- fluclox resistant
- IV vancomycin
Staph lugdonensis
- high virulence so treat as IV fluclox 2w
What type of strep causes skin and soft tissue infection?
Beta haemlytic e.g. strep pyogenes
Main types of bug causing subacute bacterial endocarditis
Viridans streptococci and enterococci
How to determine group of beta haemolytic strep?
Lancefield antigen
- positive antigen will show agglutination of the sample
Most common strep infection in pregnancy and neonates
Group B beta haemolytic strep
Faecalis vs faecium in terms of drug resistance
Faecalis - less resistant
Faecium - more resistant
Enterococcus drug resistance
(benzyl)Penicillin, Flucloxacillin, cephalosporin
aminoglycosides
Mangement of enterococcus sepsis
Amoxicillin
- vanc if amox resistant
If VRE use
- Linezolid
Daptomycin
Tigecycline
Quinupristine/Dalfopristin
Gm pos bacilli include
Clostridium
- e.g. c. tetani, diff
Corynebacterium
- c. diptheriae
Bacillus
- b. anthracis, cereus
Listeria
- l. monocytogenes
When is it esp important t consider diptheria?
Displaced populations who maybe haven’t been ale to keep up vax status
- good ID as it req antibiotics and specific toxin
WHy is meningitis treated with ceftriaxome AND amoxicillin?
Amoxicillin to cover listeria in immunocompromised people
Where are difficult to target areas with antibiotics?
Central nervous system, eyes, prostate
- site dependent antibiotic treatment
When should you consider biofilm?
Prosthetic material
- central lines, caths
Cystic fibrosis, bronchiectasis
What is mean inhibitory concentration?
concentration of drug required for kill of 99.9% of organisms during 18 to 24 hours
What might a gm pos bacilli in a blood culture suggest?
Intra-abdominal infection
Skin and soft tissue
Prosthetic material (line, device, joint etc)
Meningitis/ encephalitis/ immunosuppressed
PWID/ animal skins/black eschar
Consider contamination
Management of septic shock caused by group A strep tinea pedis
IV fluclox, clinda, gentamicin
(clinda and gent if pen allergic)
Urgent debridement if nec fac
Management sepsis 2o to group A strep tinea pedis
IV fluclox (vanc if pen allergic)
Watery vs bloody diarrhoea: how can you localise the problem?
Watery = small bowel, often viral/parasitic
Bloody = large bowel, often bacterial damage
What infection are diabetics more likely to acquire due to glycosuria?
Candida
5 main mechanisms of immunosuppression
Neutropenia e.g. leukaemia
Neutrophil dysfunction e.g. steroids
B cell problems e.g. myeloma
T cell problems e.g. chemo
Anatomic-barrier problems e.g. tumour
T cells abnormality immunosuppression puts you at risk of….
Weird bugs e.g. fungal
Post stroke SOB and cough…
Think aspiration pneumonia due to unsafe swallow
Recurrent strep pneumo warrants what type of blood test…
HIV
- jirovecci is not the only pneumonia assoc with HIV
Which patients are at high risk of aspergillosis?
Transplant
- depends on course of immunosuppression, vasc factors, steroids, CMV status etc
- due to neutropenia
(cirrhosis, post op ICU, HIV)
A. fumigatus is most common
How to investigate aspergillus?
Micro and histo of broncho-alveolar lavage
2 most common post-flu bacterial infections
Strep pneumo
Staph aureus
How does klebsiella gram stain?
Gram negative
- diverticular abscess, UTI, pneumonia
Main bugs coming from unpasteurised dairy
Brucella and listeria
How long can malaria take to present?
Up to 1 year post-travel
- always differential if travel and fever
Investigations for possible travel infection exposure
BLOOD SMEARS for malaria
FBC
(LFTS)
Blood and other cultures (see history)
Chest x-ray
Urine culture
Always consider acute HIV in non-spec symptoms
ALWAYS CONSULT ID
Causes of eosinophilia
Helminths
Sometimes viral or fungal pathogens
Also drugs, eczema, allergy, haem malig
Clin pres of severe malaria
Reduced GCS, seizures , respiratory distress, abnormal bleeding can occur, coma
Main type of malaria
Plasmodium falciparum
- 5 types
Investigation for malaria
3xThick and thin films (over 3 days)
Rapid antigen
Therapy choice depends on suspected species/ geography
Resistance can be a problem esp myanmar/cambodia
Clin pres of malaia
Palmar and conjunctival pallor
Metabolic acidosis
ARDS
Jaundice
AKI
What is enteric fever?
Slamonella typhi (thyphid)
- gm neg, treat with gm neg sensitive antibios
Fever and abdo pain
- very faint rash that can be difficult to see on dark skin
Describe pres of dengue
<14 days return from endemic area
Fever, arthralgia, leukopaenia, shock
Supportive care, no spec antivirals
Classic symptoms assoc with dengue
Retrobulbar pain
- “pain behind my eye”
Blanching rash
- very dramatic, can see your hand if you press it
Name two key viral haemorrhagic fevers
Ebola
Lassa
- very very specific IP protocol
- spread via contact and droplets
4 C antibiotics causing C diff
Clindamycin
Ciprofloxacin (and other quinolones)
Co-amoxiclav
Cephalosporins (e.g. ceftriaxone)
How can HOME criteria help guide antibiotic treatment?
Haemodynamically stable (BP normalises, apyrexial)
Oral route available (switch from IV to PO)
Markers of infection improving (WCC decr)
Exclude deep seated infection source (these req long term IV)
How long does VITEK take?
24-48h
How long does MALDITOF testing take to determine antibiotic sensitivities?
6 hours
- super super quick
Which side effects do all antibiotics cause?
Nausea, vomiting, diarrhoea, rashes, Candida infections
In which antibios should you watch LFTs?
Fluclox
Co-amox
Macrolides
Which class of antibios is now classed as last resort drugs?
Quinolones
- due to side effects on QT interval, convulsions, tendonitis
Pt turns bright red after a quick bolus dose of which antibiotic…
Vancomycin
- red person syndrome
- always given as infusion over hours
Enzyme inhibitors cause toxicity of effect of…..
Interacting drug
- most antibiotics are enzyme inhibitors
Why do you give vancomycin orla for c diff?
Local action on the gut
- almost acts as topical antibio
- molecule is too big to pass through gut if it was given IV
Pathophysiology of sepsis
Inflammation caused by pres of pathogens
Vasodilation occurs to allow products (wcc, plates) to accumulate in affected area
Capillary leakage to mobilise host response to area
Amplified response by cytokine release
Balance between pro-inflam and anti-inflam cytokines becomes deranged
Does it matter if infection is confirmed in definition of sepsis?
No, def includes suspicion of infection
NEWS <5 but followng criteria warrant further action
Mottled skin/non-blanching
Cyanosis
>2 lactate
Deteriorating since last assessment/recent intervention
Recent chemo/risk of neutropenia
High flow O2 in sepsis 6
High flow non rebreather
- to reduce tissue hypoxia
Start if sats <92, aim for 94-98
Pts at risk of hypercarbia
End stage lung disease
COPD
Neuromusc disorders of chest wall
Bloods in sepsis 6
At leats 1 set of cultures
- do cultures before FBC
FBC, UEs, LFTs, CRP, clotting, lactate
Consider other more localised cultures by examining pt
Why are antibios given in sepsis 6?
Source control
Reducing toxin burden/immune stimulus that is driving sepsis
Must be IV, quite broad spectrum
Within 1h
Fluid challenge in sepsis
Hypovolaemia contirbutes to shock
Sepsis causes fluid in wrong places, want to push it back in
Balance risk of known HF
Challenge with 20ml/kg crystalloid (hartmanns/NaCl/plasmalyte) in boluses and then reassess
- probably around 2L in 250-500ml bolus over 15-20mins
Lactate in sepsis 6
Risk strat and determine fluid response via measuring tissue hypoperfusion
Highlights pts who aren’t responding properly and may need ref’d up to HD or IC
Hourly via ABG/VBG
- high = tissue ischaemia
Urine output in sepsis 6
Tells you ab circulation and if BP is sufficient to perfuse kidneys
- low output = poor perfusion
Cath and hourly output monitoring
- targett 0.5ml/kg/hour
- e.g. 30ml /hour in 60kg pt MIN
What are you aiming for in hours 2-6 post-sepsis 6?
Fluids 20-30ml/kg
MAP >65mmHg
Urine output 30mls
Improved NEWS
Reduced lactate
Haemodynamic stability
Concerning signs in pts who are not getting better
Worsening confusion
Incr resp rate
Decr BP
Hypoglycaemia
Who needs HDU/ICU in sepsis?
Non response to interventions
- lactate remains >4 despite 20ml fluid challenge
- MAP <65mmHg (need vasopressors via central line)
Further vasopressor requirement
- ICU
Origin of strep viridans
GI tract
Gm + cocci in chains showing gamma haemolysis
Enterococcus faecalis, originates in gut
Does gentamicin have anaerobic cover?
No
What organisms does vancomycin cover?
Gm +
What type of drug is safe in type 1 penicillin allergy?
Aztreonam
How many cultures are required before antibios in sepsis?
3 sets spaced out over an hour
- then antibios
Management of staph aureus bacteraemia
IV flucloxacillin
- IV vanc if pen allergic
- treatment min 6 weeks
Most commo causative organisms in diverticular abscess
Coliforms and anaerobes
Oral antibiotics to use after source control of diverticular abscess
Oral co trimoxazole and oral metronidazole
Management of MRSA bacteraemia
IV vancomycin
Management of ESBL coliform in blood
IV meropenem
Is staph aureus coag positive or negative?
Positive
