Pyelonephritis

Question 1

What is the definition of pyelonephritis

Answer 1

inflammation of the kidney parenchyma and the renal pelvis, typically due to bacterial infection.

Question 2

Which age group and gender has the highest incidence of acute pyelonephritis

Answer 2

Women

Aged 15-29

Question 3

What does it mean when pyelonephritis is uncomplicated

Answer 3

The patient presenting has a structurally or functionally normal urinary tract and is non-immunocompromised

Question 4

What is complicated pyelonephritis

Answer 4

When there is a structural/functional abnormality in the urinary tract/ the patient is immunocompromised

Question 5

How can bacteria reach the kidney

Answer 5

Ascending through the lower urinary tract

Via the blood ( as is the case in septicaemia/infective endocarditis)

Via lymphatics

Question 6

What happens during the inflammatory process

Answer 6

Neutrophils infiltrate the tubules and interstitium and cause suppurative inflammation.

Question 7

what are the common infective organisms in pyelonephritis

Answer 7

E-coli ( 80% )

Staph aureus ( catheters )

Staphylococcus saprophyticus

Enterococcus faecalis (catheters)

Pseudomonas ( catheters )

Question 8

What are the categories of risk factors we need to think about when thinking out pyelonephritis

Answer 8

Factors reducing antegrade flow of urine

Factors promoting retrograde ascent of bacteria

Factors predisposing to infection or immunocompromise

Factors promoting bacterial colonisation

Question 9

What are some things that reduce antegrade flow of urine

Answer 9

BPH

Obstructed urinary tract

Neuropathic bladder from spinal cord injury

Meatal stenosis

Question 10

What factors promote retrograde ascent of bacteria

Answer 10

Female gender ( short urethra )

Indwelling catheter

vesico-ureteric reflux (VUR)

Question 11

What are factors that predispose to infection/immunocompromise

Answer 11

Diabetes mellitus, corticosteroid use, HIV infection (untreated)

Question 12

what factors promote bacterial colonisation

Answer 12

Renal calculi

Sexual intercourse

Oestrogen depletion (menopause)

Question 13

What is the classical triad for pyelonephritis

Answer 13

fever
unilateral loin pain (or rarely bilateral),
and nausea & vomiting,

typically developing over the course of 24-48 hours.

Question 14

What other sx other than the classical triad may pts with pyelonephritis also have

Answer 14

LUTI sx

Dysuria
Frequency
Urgency

Visible/non visible haematuria

Question 15

What would the findings be on examination of a pt with pyelonephritis

Answer 15

Pyrexial ( possibly features of sepsis )

unilateral or bilateral costovertebral angle tenderness*, with or without suprapubic tenderness.

Question 16

What are the differential diagnosis

Answer 16

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

Question 17

What investigations would you carry out to investigate pyelonephritis

Answer 17

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)

Question 18

How do you treat systemically unwell pts

Answer 18

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.

Question 19

Most pts with pyelonephritis can be treated in the community however who should you consider admission into the hosp

Answer 19

clinically unstable, significant dehydration, or with co-morbidities such as diabetes mellitus, renal transplant graft, immunocompromised.

Question 20

What are the complications of pyelonephritis

Answer 20

Chronic pyelonephritis

Emphysematous pyelonephritis

severe sepsis and multi-organ failure,

renal scarring leading to chronic kidney disease

pyonephrosis

preterm labour in pregnant women

Question 21

What is chronic pyelonephritis

Answer 21

Repeated infections of the kidney leading to repetitive inflammatory events leading to scarring and ultimately destruction of the kidney

Question 22

When is chronic pyelonephritis more common

Answer 22

In cases of urinary reflux eg - UTI, VUR and other anatomical abnormalities

Question 23

when is the diagnosis of chronic pyelonephritis made

Answer 23

When a small, scarred, shrunken kidney is seen of US

Question 24

How do you treat chronic pyelonephritis

Answer 24

Treat any underlying causes

Question 25

What is emphysematous pyelonephritis

Answer 25

rare and severe form of acute pyelonephritis, caused by gas-forming bacteria, and is associated with a high-mortality rate.

Question 26

How does Emphysematous Pyelonephritis present

Answer 26

Same way as acute pyelonephritis however it fails to respond to IV abx

CT imaging will how gas within and around the kidney

Question 27

In which pts is Emphysematous Pyelonephritis most common in

Answer 27

Diabetic as the high glucose allows for co2 production from fermentation by enterobacteria.

Question 28

How is Emphysematous Pyelonephritis treated

Answer 28

Mild cases can be treated with broad-spectrum anti-microbial cover.

Severe cases may warrant either nephrostomy insertion or percutaneous drainage