Pyelonephritis Flashcards
What is the definition of pyelonephritis
inflammation of the kidney parenchyma and the renal pelvis, typically due to bacterial infection.
Which age group and gender has the highest incidence of acute pyelonephritis
Women
Aged 15-29
What does it mean when pyelonephritis is uncomplicated
The patient presenting has a structurally or functionally normal urinary tract and is non-immunocompromised
What is complicated pyelonephritis
When there is a structural/functional abnormality in the urinary tract/ the patient is immunocompromised
How can bacteria reach the kidney
Ascending through the lower urinary tract
Via the blood ( as is the case in septicaemia/infective endocarditis)
Via lymphatics
What happens during the inflammatory process
Neutrophils infiltrate the tubules and interstitium and cause suppurative inflammation.
what are the common infective organisms in pyelonephritis
E-coli ( 80% )
Staph aureus ( catheters )
Staphylococcus saprophyticus
Enterococcus faecalis (catheters)
Pseudomonas ( catheters )
What are the categories of risk factors we need to think about when thinking out pyelonephritis
Factors reducing antegrade flow of urine
Factors promoting retrograde ascent of bacteria
Factors predisposing to infection or immunocompromise
Factors promoting bacterial colonisation
What are some things that reduce antegrade flow of urine
BPH
Obstructed urinary tract
Neuropathic bladder from spinal cord injury
Meatal stenosis
What factors promote retrograde ascent of bacteria
Female gender ( short urethra )
Indwelling catheter
vesico-ureteric reflux (VUR)
What are factors that predispose to infection/immunocompromise
Diabetes mellitus, corticosteroid use, HIV infection (untreated)
what factors promote bacterial colonisation
Renal calculi
Sexual intercourse
Oestrogen depletion (menopause)
What is the classical triad for pyelonephritis
fever
unilateral loin pain (or rarely bilateral),
and nausea & vomiting,
typically developing over the course of 24-48 hours.
What other sx other than the classical triad may pts with pyelonephritis also have
LUTI sx
Dysuria
Frequency
Urgency
Visible/non visible haematuria
What would the findings be on examination of a pt with pyelonephritis
Pyrexial ( possibly features of sepsis )
unilateral or bilateral costovertebral angle tenderness*, with or without suprapubic tenderness.
What are the differential diagnosis
Any patient present with back pain and tachycardia and / or hypotension, especially if elderly or with sufficient risk factors, should be assessed for a potential ruptured AAA.
Renal calculi
acute cholecystitis, ectopic pregnancy or pelvic inflammatory disease, lower lobe pneumonia, or diverticulitis
What investigations would you carry out to investigate pyelonephritis
Urinalysis - nitrates, leucocytes, urinary b-hcg
Urine culture ( start broad spec Abx after sending )
Routine bloods - FBC, CRP, U&Es
Renal US scan - to see if obstruction
If obstruction suspected - non constrast CT imaging ( CT KUB)
How do you treat systemically unwell pts
A to E approach and appropriate resuscitation.
empirical antibiotics based on local protocols and IV fluids as appropriate, also prescribing suitable analgesia and anti-emetics. Tailor antibiotic therapy once sensitivities are available.
Most pts with pyelonephritis can be treated in the community however who should you consider admission into the hosp
clinically unstable, significant dehydration, or with co-morbidities such as diabetes mellitus, renal transplant graft, immunocompromised.
What are the complications of pyelonephritis
Chronic pyelonephritis
Emphysematous pyelonephritis
severe sepsis and multi-organ failure,
renal scarring leading to chronic kidney disease
pyonephrosis
preterm labour in pregnant women
What is chronic pyelonephritis
Repeated infections of the kidney leading to repetitive inflammatory events leading to scarring and ultimately destruction of the kidney
When is chronic pyelonephritis more common
In cases of urinary reflux eg - UTI, VUR and other anatomical abnormalities
when is the diagnosis of chronic pyelonephritis made
When a small, scarred, shrunken kidney is seen of US
How do you treat chronic pyelonephritis
Treat any underlying causes
What is emphysematous pyelonephritis
rare and severe form of acute pyelonephritis, caused by gas-forming bacteria, and is associated with a high-mortality rate.
How does Emphysematous Pyelonephritis present
Same way as acute pyelonephritis however it fails to respond to IV abx
CT imaging will how gas within and around the kidney
In which pts is Emphysematous Pyelonephritis most common in
Diabetic as the high glucose allows for co2 production from fermentation by enterobacteria.
How is Emphysematous Pyelonephritis treated
Mild cases can be treated with broad-spectrum anti-microbial cover.
Severe cases may warrant either nephrostomy insertion or percutaneous drainage
