Common Infections Flashcards
Following the O’Neil review on Antimicrobial resistance, NHS England introduced which two quality premiums for 2017-2019
- Reducing gram negative blood stream infections across the whole health economy by at least 10%
- Reduction of inappropriate antibiotic prescribing for UTI’s in primary care by at least 10%
Signs and symptoms of lower UTI
back pain dysuria polyuria & urgency haematuria subrapubic tenderness
Additionally:
fever, chills, flank pain, renal angle tenderness, N&V would be for an upper UTI
Most common organism causing UTI
E.coli
Other possible are : proteus app, enterobacter app, enterococcus app, staphylococcus app, pseudamonus aeruginosa.
What part of the urinary tract is a lower UTI and what is its other name?
Bladder and urethra
cystitis
What part of the urinary tract is an upper UTI and what is its other name?
Ureter and kidneys
Pyelonephritis
Give some examples of co-morbidities when a UTI would be complicated…
- poorly controlled diabetes mellitus
- pregnancy
- AKI or CKD
- suspected or known urinary tract obstruction
- presence of an indwelling urethral catheter, stent, nephrostomy tube or urinary diversion
- functional or anatomic abnormality of the UTI
- renal transplant
- other immunocompromising conditions (neutropenia, advanced HIC, chronic high dose corticosteroid use, B or T leukocyte deficiency)
Should we give ABX to elderly if they have bacteruria?
No because prevalence of this rises with age due to poor immune system, higher intravaginal pH in post menopausal women, bladder outlet obstruction etc. They may not actually be sick with it.
Why is the prevalence of UTI’s less in women than men
They have a longer urethra so further for bacteria to travel. Their prostatic fluid has some antibacterial properties and a drier periurethral environment.
This is why all mens UTI’s are classes as complicated.
Is a urine dipstick test a reliable test in patients with catheter?
No because between two - ten days after catheter insertion around 30% of patients have bacteruria so will yield a positive dipstick result
What do we test for with urine dipstick?
nitrates (urinary nitrates break down to nitrated by the bacteria) leucocyte esterase (produced by the increased neutrophils present in the urine)
urine microscopy, sensitivity and testing……
pyuria - white blood cells
haematuria - erythrocytes
bacteruria - bacteria
not individually a positive result for an infection but together they can be
When is urine culture recommended…..
- Those who have failed first line therapy or have persistent symptoms
- Pregnant women at their first antenatal visit (as asymptomatic bacteria is associated with pyelonephritis and premature delivery and should always be treated)
- suspected UTI in med
- Suspected pyelonephritis
- Recurrent UTI, anatomical abnormalities of the genitourinary tract and those with renal impairment (as they are more likely to be associated with resistant organisms)
first line ABx for uncomplicated UTI in in women and men (complicated)
trimethoprim
nitrofurantoin
women 3/7
men 7/7
What ABX would we start with in pyelonephritis whilst waiting for cultures to come back?
cipro, co-amoc or gent
then start smart then focus
When can we use nitro in patients with eGFR <45ml/min
When their eGFR 30-45ml/min
They have a lower UTI and can only be treated for a short course 3-7/7
They are suspected to have multi drug resistance
benefit outweighs the risk
Approximately 25-30% of nitro is excreted in the urine and in renal impairment the desired concentration is not achieved
Can we use nitrofurantoin in upper UTI
plasma concentrations of a therapeutic dose are low therefore they are nota good candidate for UUTI.
What things do we counsel when patient is on nitrofurantoin
Not to take alkalising agents such as potassium citrate as it is affected by urinary pH.
Also to take with food as it is better absorbed with gastric contents.
What bacteria can cause skin and soft tissue infections?
- beta-haemolytic streptococci (usually streptococcus pyogenes)
- staphylococcus aureus.
Therefore vigilance to MRSA is important especially if response to treatment is poor.
How does bacteria cause necrotising fasciitis?
Bacteria produce two exotoxins - a protease that degrades host cell proteins and a ‘super antigen’ that excited the immune system causing healthy cells to commit suicide (apoptosis)
A similar skin condition like cellulitis but involved the upper dermis?
erysipelas - it involved the upper-dermis and is raised above the skin with a well-demarcated edge.
Cellulitis involved the deeper dermic and s/c fat. It does not have a well-demarcated edge.
fresh water and sea water pathogens that may cause infections
fresh water - aeromonas species
sea water - vibrion vulnificus
Panton-Valnetine Leukocidine (PVL) toxin destroys white blood cells and is produced by some Staph aureus
suspect this in patients with necrotising SSTI, recurrent furuncles/carbuncles or clustering os SSTI’s. Remember the 5 C’s
Contaminated items Close contact Crowding Cleanliness (or lack of) Cuts
What guidelines should be followed to determine the severity of cellulitis?
CREST
Class 1 - fine - oral ABX
Class 2 - well or unwell but an uncontrolled co-morbidity such as vasculitis
Class 3 - systemic upset e.g. confusion, lethargy and may have co-morbidy may be limb/life threatening
class 4 - sepsis or necrotising facititis
treatments for cellulitis
flucloxacillin
flucloxacillin + ben pen
co-amoxiclav
