Infection Station Flashcards
What is the main iatrogenic precipitant of C.diff?
Antibiotic use (particularly broad spec)
Which antibiotic is the main culprit for C.diff?
Ceftriaxone
How is C.diff transmitted?
As spores
What hygiene precaution is important with C.diff?
Wash hands WITH SOAP AND WATER
What gives C.diff its unique hygiene rule?
Ability of spores to survive alcohol gel
Is C.diff always pathological?
No - 3% of the population have it as normal gut flora
How does C.diff cause illness?
Releases toxins that cause cytokine release and cell damage and death
What is the name given to C.diff’s effect in the bowel?
Pseudomembranous colitis
What symptoms present in C.diff?
Diarrhoea Abdo pain Fever Malaise Nausea
What investigations should be done in C.diff?
NEWS
Stool sample
What effect can C.diff have in peristalsis?
Stop it
What does the cessation of peristalsis in C.diff risk?
Bowel perforation
Sepsis
What is looked for on stool sample in C.diff?
Antigens
Toxins
What stool sample result means that C.diff is at a pathological level?
Toxin positive
Why is NEWS important in C.diff?
Look for early warning signs of sepsis
What medication is used to treat C.diff?
Metronidazole
What other management steps (besides antibiotics) should be taken in C.diff?
Isolate patient
Stop previous antibiotics
Ensure good hand hygiene
Use PPE
What should be remembered about metronidazole?
It is a CYP450 inhibitor
What are the common 3 organisms causing CA pneumonia?
Strep pneumoniae
Klebsiella pneumoniae
Haemophilus influenzae
What type of organisms most commonly cause HA pneumonia?
Mostly gram-ve rods
What antibiotic used to treat first line mild CAP?
Amoxicillin
Second lines in mild CAP?
Macrolide
Tetracycline
What are some symptoms of pneumonia?
SoB Rigors Fever Cough +/- sputum Pleuritic chest pain Malaise N+V
What are two rarer causes of CAP?
Mycoplasma
Staph aureus
What score is used to assess CAP?
CURB65
What does C mean in CURB65?
New onset Confusion
What does U mean in CURB65?
Urea >7
What does R mean in CURB65?
RR≥30
What does B mean in CURB65?
SBP ≤90 or DBP ≤60
What does 65 mean in CURB65?
Age >65
What does each aspect of CURB65 score?
1 point
A score of what should lead to admission to hospital?
≥2
What antibiotics are used for mild HAP?
Amoxicillin
What antibiotic should be used for Moderate-Severe HAP?
Ceftriaxone
Why is Ceftriaxone used in more severe HAP?
It is more effective against Gram -ve bacteria (the most common cause of HAP)
Why is tetracycline (+amoxicillin) used in severe CAP?
Broad spectrum to cover the Gram +ve/-ve organisms that can commonly cause CAP
What investigations should always be done in pneumonia?
FBC U&E CRP ABG CXR Sputum culture
What tests can be added if you fancy for pneumonia?
Blood culture
Lavage
Serum antibody
Nose and throat swabs
What are some possible examination findings of pneumonia?
Tachycardia Tachypnoea Pyrexia Cyanosis Dull percussion Increased tactile vocal fremitus/resonance Bronchial breathing Crackles
After what time period is onset of pneumonia post-hospital admission consider HAP?
> 48 hours
What is bacteriuria?
Bacteria in urine (a/symptoamtic)
What is a UTI?
Symptomatic w/ +ve culture or dipstick
What is urethral syndrome?
Symptomatic but no bacteriuria
What is an uncomplicated UTI?
UTI in normal GU tract and function
What is a complicated UTI?
UTI in abnormal GU tract/function
and all men sometimes
What are the 3 presentations of UTI’s?
Pyelonephritis
Cystitis
Prostatitis
How does pyelonephritis present?
Fever
Loin pain
Vomiting
Potentially oliguria if AKI
How does cystitis present?
Frequency Urgency Polyuria Dysuria Suprapubic tenderness Foul smelling urine
How does prostatitis present?
Flu-like symptoms
Low back ache
Dysuria
Tender prostate on PR
What are the risk factors for UTI?
Female Sexual activity Pregnancy Menopause DM Abnormal tract
What can constitute an abnormal urinary tract?
Stones
Obstructions
Catheter
Malformation
What is the most common organism causing UTI?
E. coli
What less organisms can cause UTI?
Staphylococcus Saprophyticus
Proteus
Klebsiella
What investigations should be done for UTI?
Dipstick
MSU for MCS
Bloods
USS in children, men, recurrent or pyelonephritis
How can UTI be managed non-pharmacologically?
Drink plenty
Urinate often
What is the first line for cystitis?
Nitrofurantoin
What is second line for cystitis?
Trimethoprim
What can contra-indicate use of nitrofurantoin?
eGFR <45
What can be used to treat pyelonephritis?
Cefotaxime
How should UTI’s be prevented?
Drink more
Abx prophylaxis (in serious recurrent cases)
Drink cranberry juice (caution with drug interactions)
Wipe front to back
When should septic arthritis be suspected?
Any acutely inflamed joint
Why is it important to be highly suspicious of septic arthritis?
Can destroy a joint in <24 hours
What is the mortality rate of septic arthritis?
11%
What is the most commonly affected joint in septic arthritis?
Knee
How should septic arthritis be investigated?
Joint aspiration for microscopy and culture
Blood cultures
When must aspiration and blood cultures be taken?
Before starting empirical antibiotics
What are some major risk factors for septic arthritis?
Immunosuppression
DM
Prosthetic joints
Recent joint surgery
When is septic arthritis particularly difficult to treat?
In prosthetic joints
What is the main differential for septic arthritis?
Crystal arhtopathies
What are the main crystal arthropathies?
Gout
Pseudo-gout
What will be seen on microscopy of joint aspirate in septic arthritis?
Increased WCC
What will be seen on microscopy of joint aspirate in gout?
Needle shaped urate crystals
What will be seen microscopy of joint aspirate in pseudo-gout?
Rhomboid shaped crystals
What colour is joint aspirate in septic and crystal arthropathies?
Turbid yellow
How can a joint become septic?
Direct introduction of bacteria
Deposition of bacteria via systemic spread
What are the most common causative organisms of septic arthritis?
Staph aureus
Strep
What is a good empirical antibiotic to use in septic arthritis?
IV flucloxacillin
How long are antibiotics used in septic arthritis?
2-4 weeks
What antibiotic should be used if there is a suspected gram -ve cause of septic arthritis?
IV ceftriaxone
Where does appendicitis pain begin?
Umbilical region
Where does appendicitis pain localise?
RIF
What are the symptoms of appendicitis?
Abdo pain
Nausea and vomiting
Diarrhoea
Lost appetitie
How is appendicitis treated?
Mostly with removal of the appendix
How is an appendectomy performed?
Laparoscopy
What antibiotic used for cellulitis?
Flucloxacillin
How can the symptoms of meningitis be classified?
Meningitic
Neurological
Septic
What are the meningitic symptoms of meningitis?
Headache
Neck stiffness
Photophobia
N&V
What are the neurological features of meningitis?
Decreased GCS
Seizures
Focal neurological signs
What are the septic features of meningitis?
Sepsis
What organisms can cause meningitis?
HSV2 Meningococcus Pneumococcus Haemophilus TB Cryptococcus
What investigations are required for meningitis?
Bloods
Blood cultures
Lumbar puncture*
When should LP not be performed in meningitis?
When the patient is mainly septic
When should LP be performed in meningitis?
When the patient is mainly meningitic
If a meningitis patient is mainly septic what medication should be given?
Ceftriaxone
If a patient is mainly meningitic what medications should be given?
Ceftriaxone
Dexamethasone
What supportive therapies should be given in meningitis?
Oxygen
Fluids
What can be given as prophylaxis to household contacts of patients with meningitis?
Rifampicin
