Pyelonephritis Flashcards
What is Pyelonephritis?
Inflammation of the kidney parenchyma and the renal pelvis, usually due to bacterial infection
What is uncomplicated pyelonephritis?
Structurally or functionally normal urinary tract in a non-immunocompromised host
Whats complicated pyelonephritis?
Structurally or functionally abnormal tract in immunocompromised patient
What kind of pyelonephritis is present in a man?
Complicated as it will be due to an abnormal urinary tract
How does bacteria reach the kidney?
Ascending from the lower urinary tract, directly from the blood stream, lymphatics
How does bacteria reach the kidney via the blood stream?
septicaemia or infective endocarditis
How does bacteria reach the kidney via the lymphatics?
retroperitoneal abscess
What happens at a cellular level in pyelonephritis?
Neutrophils infiltrate the tubules and interstitial and cause suppurative inflammation, this causes small renal cortical abscesses and streaks of pus in the renal medulla
What is the most common organism that causes Pyelonephritis?
Escherichia Coli
What organisms cause pyelonephritis in catheters?
Entercoccus faecalis
Staphlococcus aureus, staphylococcus saprophyticus
pseudonomas
Other than bacteria, what can cause pyelonephritis?
yeasts or fungi in immunocompromised patients (also mycobacterium app)
What are the risk factors for Pyelonephritis?
Factors that reduce the antegrade flow of urine, factors that promote retrograde ascent of bacteria, factors predisposing to infection or immunocompromise, Factors promoting bacterial colonisation
What factors reduce integrate flow of urine?
Obstruction in the urinary tract e.g. BPH, spinal cord injury resulting in neuropathic bladder
What factors promote retrograde ascent of bacteria?
Female as have shorter urethra
Indwelling catheter or ureteric stents/ nephrostomy tubes in situ,
structural renal abnormalities such as vesicle-ureteric reflux
What factors predispose to infection or immunocompromised?
Diabetes mellitus, corticosteroid use, HIV infection
What factors promote bacterial colonisation?
Renal calculi, sexual intercourse, oestrogen depletion
What is the classical triad for pyelonephritis?
Fever, unilateral loin pain (rarely bilateral) and nausea and vomiting developing over 24-48 hours
What are the symptoms of a lower urinary tract infection?
Frequency, urgency and dysuria with or without haematuria
What would be found on examination of someone with Pyelonephritis?
Look unwell, pyrexia, and sepsis, costovertebral angle tenderness with or without suprapubic tenderness
What are the differential diagnosis for pyelonephritis?
if have backspin, tachycardia and or hypotension is at risk of a potential ruptures AAA
Also Renal calculi, acute cholecystitis, ectopic pregnancy or PID, lower lobe pneumonia or diverticulitis
What investigations would you do for someone with a suspected Pyelonephritis?
urinalysis looking for nitrites and leucocytes
Urinary beta HCG for women of child bearing age
urine culture, routine bloods to assess inflammation and renal function
Renal US scan to check for obstruction, and then non contrast CT imaging of renal tract (CT KUB)
Is infected obstructed of the emergency tract an emergency?
Yes
What is the management for pyelonephritis?
Fluid resuscitation, antibiotics, analgesia and anti emetics
Non-responding cases may need catheterisation and HDU as can become rapidly unwell
When should someone be admitted to hospital with pyelonephritis?
clinically unstable, significant dehydration, co morbidities such as diabetes, renal transplant or immunocompromised
What should be done in the case of a man with pyelonephritis?
further imaging such as US or CT KUB, and a flexible cystoscopy to find cause
What are some complications of pyelonephritis?
severe sepsis, renal scaring, chronic kidney disease, pyeonephrosis, preterm labour, chronic pyelonephritis, emphysematous pyelonephritis
What is chronic pyelonephritis?
repeated infections, which then causes fibrosis and scarring and then destruction of the kidney, usually occur in obstruction, causing urinary reflux e.g. structures, diagnosis made from imaging as scarred shrunken kidney is seen, more common in children, manage by reversing cause, antibiotics and optimise renal function
What is emphysematous pyelonephritis?
Rare and severe form of acute pyelonephritis, caused by a gas forming bacteria, has a high mortality rate, fail to respond to antibiotics, CT will show gas within and around the kidney, more common in diabetic patients, as high glucose allows CO2 production from fermentation by enterobacteria, may be treated with broad spectrum anti-microbial cover, nephrostomy insertion or percutaneous drainage or nephrectomy
