Pyelonephritis

Question 1

What is pyelonephritis?

Answer 1

Pyelonephritis is an infection of one or both kidneys usually caused by bacteria from the bladder.

Question 2

What are the common causative organisms of pyelonephritis?

Answer 2

• Escherichia coli (60-80% of uncomplicated infections)
• Klebsiella species (20%)
• Proteus mirablis (15%)
• Pseudomonas species
• Enterobacter species

Question 3

How may signs and symptoms differ between lower UTI and pyelonephritis?

Answer 3

There are no clinical features or routine investigations that conclusively distinguish acute pyelonephritis from lower urinary tract infection.

However, the triad of flank pain (typically unilateral), fever, and nausea and vomiting occurs much more often in people with pyelonephritis than in those with lower urinary tract infection.

Question 4

What are the risk factors for pyelonephritis?

Answer 4

• History of urinary tract infections (UTIs)
• Stress incontinence
• Diabetes
• Presence of a catheter or renal stones
• Anatomical or functional urinary abnormality
• Immunosuppression
• Consider use of corticosteroids
• Family history of UTI
• Frequent sexual intercourse

Question 5

What anatomical or functional urinary abnormalities may predispose to pyelonephritis?

Answer 5

Consider polycystic disease, enlarged prostate, vesicoureteric reflux, uteroceles, and neurogenic bladder.

Question 6

What are the signs of pyelonephritis?

Answer 6

• Costovertebral angle tenderness
• Raised temperature of >37.9°C
• Hypotension
• Tachycardia

Question 7

What are the symptoms of pyelonephritis?

Answer 7

• Flank pain
• Fever
• Rigors
• Nausea and vomiting
• Flu-like symptoms

Question 8

What investigations shoud be ordered for pyelonephritis?

Answer 8

• Urine culture and sensitivity
• Urine dipstick?

Question 9

Briefly describe the use of urine dipstick in the diagnosis of pyelonephritis

Answer 9

Dipstick testing of urine for nitrites and leukocytes is not necessary, however it may be a useful adjunct to guide diagnosis in some clinical situations. It should not be used in people:

• With an indwelling catheter
• Aged over 65 years

Question 10

Briefly describe the role of urine culture and sensitivity in pyelonephritis

Answer 10

In all people suspected of having acute pyelonephritis, arrange collection of a mid-steam urine (MSU) or catheter specimen of urine (CSU), to determine the infecting micro-organism.

Obtain a urine sample for culture before starting empirical drug treatment.

Question 11

How is a definitive diagnosis of pyelonephritis made?

Answer 11

A definitive diagnosis of acute pyelonephritis is made in people with loin pain and/or fever if a UTI is confirmed by culturing a urinary pathogen from the urine, and other causes of loin pain and/or fever have been excluded.

Question 12

What signs and symptoms may indicate sepsis?

Answer 12

• Significant tachycardia, hypotension, or breathlessness
• Marked signs of illness (such as impaired level of consciousness, perfuse sweating, rigors, pallor, significantly reduced mobility)
• A temperature greater than 38°C or less than 36°C.

Question 13

What is the first-line treatment for pyelonephritis?

Note: women who are not pregnant, men and people with indwelling catheters

Answer 13

Co-amoxiclav 500/125 mg three times a day for 7-10 days.

Question 14

What is the second-line treatment for pyelonephritis?

Note: women who are not pregnant, men and people with indwelling catheters

Answer 14

Ciprofloxacin 500 mg twice a day for 7 days.

Question 15

What are the complications of pyelonephritis?

Answer 15

• Sepsis
• Parenchyma renal scarring
• Recurrent urinary tract infections
• Renal abscess formation
• Preterm labour in pregnancy
• Emphysematous pyelonephritis

Question 16

What differentials should be considered for pyelonephritis?

Answer 16

1. Cystitis
2. Acute prostatitis
3. Pelvic inflammatory disease (PID)

Question 17

How does pyelonephritis and cystitis differ?

Answer 17

Differentiating signs and symptoms:

• Does not display systemic signs or symptoms (e.g., fevers, chills, nausea, vomiting, and back pain)

Differentiating investigations:

• Often associated with a urinary tract infection, manifesting with symptoms of dysuria, urgency, and frequency
• No differentiating tests exist

Question 18

How does pyelonephritis and prostatitis differ?

Answer 18

Differentiating signs and symptoms:

• In men, urinary symptoms along with fever or systemic symptoms may indicate acute prostatitis
• Acute prostatitis may present with:
  
  • Sudden onset of fever
  • Low back, suprapubic, perineal, or rectal pain
  • Symptoms of urinary tract infection (dysuria, frequency, urgency, or retention)
• Digital rectal examination reveals a tender, often enlarged prostate

Differentiating investigations:

• Microscopic analysis shows WBCs in urine obtained after prostate massage or by collection of the terminal portion of a urine sample

Question 19

How does pyelonephritis and pelvic inflammatory disease (PID) differ?

Answer 19

Differentiating signs and symptoms:

• Determined via a history of sexual intercourse; lower abdominal, pelvic, or low back pain; pain with movements; vaginal discharge; fevers or chills; abdominal or cervical tenderness
• Pelvic examination may show vaginitis, urethral discharge, or herpetic ulcerations.
• Cervical examination may show cervicitis

Differentiating investigations:

• Cervical cultures can identify causative pathogens (e.g. Neisseria gonorrhoeae, Chlamydia trachomatis)
• Microscopic examination of vaginal discharge demonstrates neutrophils