Pyelonephritis

Question 1

What is pyelonephritis?

Answer 1

• inflammation of the kidney parenchyma and the renal pelvis

Question 2

Where does the source of infection originate in pyelonephritis?

Answer 2

• ascending infection from bladder
• haematogenous spread

Question 3

What are the causative organism for pyelonephritis?

Answer 3

• Escherichia coli
• Klebsiella spp.
• Proteus spp.
• Enterococcus spp

Question 4

What is the incidence of acute pyelonephritis?

Answer 4

• highest in women aged 15-29
• Infants
• older people

Question 5

What are the RF for acute pyelonephritis?

Answer 5

• Structural renal abnormalities, including vesicoureteric reflux (VUR).
• Calculi and urinary tract catheterisation.
• Stents or drainage procedures.
• Pregnancy.
• Diabetes.
• Primary biliary cirrhosis.
• Immunocompromised patients.
• Neuropathic bladder.
• Prostate enlargement

Question 6

What is the presentation of acute pyelonephritis?

Answer 6

Classical triad (develop over 1-2days)

• fever
• unilateral loin pain
• N&V

Others

• suprapubic pain
• frequency, urgency, dysuria, haematura
• pyrexial, sepsis
• costoverbal angle tenderness

Question 7

What are the differentials for acute pyelonephritis?

Answer 7

• Abdominal aortic aneurysm.
• Appendicitis.
• Causes of loin pain.
• Diverticulitis.
• Ectopic pregnancy.
• Endometritis.
• Interstitial cystitis.
• Nephrolithiasis.
• Pelvic inflammatory disease.
• Prostatitis.
• Renal vein thrombosis.
• Salpingitis.
• Sexually transmitted infections.
• Urethritis.
• Vesicovaginal and ureterovaginal fistula.

Question 8

What Ix would you order for acute pyelonephritis?

Answer 8

Urine

• urinanalysis
• MSU for MCS
• b-hCG

Bloods

• FBC, U&E, CRP (inflammatory markers will raise)
• culture

Imaging

• renal USS
• contrast enhanced CT (CECT)
• non contrast CT KUB
• MRI

Question 9

How would you mx acute pyelonephritis?

Answer 9

• A-E c resuscitation
• Empirical abx
  
  • ciprofloxacin or co-amoxiclav for 7 days (500 mg bd or 500/125 mg tds respectively)
  • Trimethoprim may be used if culture confirms sensitivity (200 mg bd for 14 days)
• Surgery: to drain renal or perinephric abscesses, or to relieve obstructions causing the infection (eg, stones)

Question 10

What is the cx of acute pyelonephritis?

Answer 10

• Sepsis
• Perinephric abcess
• Renal abcess
• Chronic pyelonephritis
• Emphysematous pyelonephritis
• Acute papillary necrosis
• AKI or CKD

Question 11

What is chronic pyelonephritis?

Answer 11

• Fibrosis (scarring) of kidney due to repeated or persistent infection

Question 12

What are the RK for chronic pyelonephritis?

Answer 12

• Any structural renal tract anomalies, obstruction or calculi.
• VUR (vesicoureteric reflux)
• Intrarenal reflux in neonates.
• Diabetes.
• Any factors predisposing to recurrent urinary infection - eg, neurogenic bladder.

Question 13

What is Emphysematous pyelonephritis?

Answer 13

• Rare and severe form of acute pyelonephritis, caused by gas-forming bacteria

Question 14

Which patient group is emphysematous pyelonephritis most common in and why?

Answer 14

• diabetic patients
• high glucose allows CO2 production from fermentation by enterobacteria

Question 15

How does emphysematous pyelonephritis present?

Answer 15

• similar to acute pyelonephritis
• fail to respond to IV empirical abx

Question 16

How would you mx emphysematous pyelonephritis?

Answer 16

• broad spec abx - mild
• nephrostomy insertion
• percutaneous drainage