UTI & Acute Kidney Injury

What structures are involved in upper urinary tract infections?

ureters

kidneys ~ pyelonephritis

What structures are involved in lower urinary tract infection?

urethra

bladder ~ acute cystitis

What structure is the most common site for UTI?

bladder ~ acute cystitis

What is the order of pathogenesis of a UTI?

colonization of the urethra where bacterial colonization in the periurethra allows for ascension via the urethra

uroepithelium penetration - bladder - bacterial fimbriaea allows for attachment and penetration of bladder epithelial cells ~ acute cystitis

Ascension of the ureters - sufficient bacterial colonization can lead to bacterial ascension through the ureters

pyelonephritis of the kidneys - bacterial ascension or hematogenous spread infects the renal parenchyma and results in pyelonephritis

acute kidney injury - continuous inflammatory response results in interstitial edema, interstitial nephritis, and ultimately acute kindey injury (AKI)

What are five common symptoms of a lower UTI?

frequent urge to urinate

burning or pain sensation when urinating

incomplete emptying of the bladder sensation

cloudy or reddish urine

foul-smelling urine

What are 5 potential symptoms that may be experienced if the bacteria enter the ureters and spread to the kidneys (UTI)?

pain in lower back (kidneys in bilateral back)

chills

fever

nausea

vomiting

What are the two main risk factors that contribute to the development of a UTI?

The ability of the specific pathogen to produce infection

the strength of the individual’s defense mechanisms against the specific pathogen

Which six individuals are at most risk for urinary tract infections?

women

immunocompromised individuals

prepubescent children

patients with urinary catheters

individuals with a history of diabetes mellitus

post-menopausal

Define an uncomplicated UTI.

mild UTI, without complications and occur in normal urinary tracts

Define a complicated/febrile UTI.

abnormality in urinary system or individual has a health problem that compromises the host’s defenses

Define a recurrent UTI.

three or more UTIs in 12 months or 2 or more occurrences within 6 months

What is a relapse in UTI?

a second UTI caused by the same pathogen within two weeks of first treatment

What is reinfection in UTI?

A UTI that occurs greater than two weeks after completing treatment for the same or a different pathogen

Urethritis is a common condition that causes _____________.

inflammation in urethra

What is the most common cause of urethritis?

infections

What two other causes may lead to the development of urethritis?

trauma

irritant

Symptoms of Urethritis in first stage include:

itchiness in urethra

pain/burning while urinating

discharge

blood in urine

T/F: Acute cystitis is the least common site of a UTI.

false. it is the most common site

Acute cystitis also means:

inflammation of the bladder

What causes acute cystitis?

urine is contaminated by bacteria that makes its way up to the bladder

Most commonly, a UTI occurs through hte reversed movement of pathogens or bacteria from the gut up to the urethra then to the bladder

Symptoms of bladder inflammation:

Frequent urination

sudden urge to urinate

internal pain/burning during urination

dark/odorous urine

Symptoms associated with Pyelonephritis:

fever

pain in lower back or side

chills

pain when urinating

bloody or cloudy urine that may smell

urgent/frequent need to urinate

Pyelonephritis also means:

kidney infection - a type of UTI

How is pyelonephritis caused?

bacteria cause it when they move from another part of your body up to one or both of your kidneys

Which microorganisms are usually associated with acute pyelonephritis?

e. coli

proteus

pseudomonas

Acute kidney injury (AKI) was previously called:

acute renal failure (ARF)

AKI denotes a ______ and often ________ reduction in ________ function.

sudden

reversible

kidney

How to measure kidney function with AKI?

GFR - glomerular filtration rate

Acute kidney injury is the presence of:

Increase in serum creatinine by ___________

Increase in serum creatinine _____________

Urine volume less than _____________

0.3 mg/dL or more within 48 hours

1.5X or more than the baseline of the prior 7 days

0.5 mL/kg/h for at least 6 hours

AKI is a clinical diagnosis. How is it established?

It is established by clinical/laboratory parameters, not by pathologic or histologic findings.

What is the range of AKI?

an asymptomatic transient increase in serum creatinine to a fairly rapid presentation of kidney failure

A single isolated elevated serum Creatinine does not make the ___________, unless a baseline value from the past _____ is known - if it is _____ it may reflect. _____________.

diagnosis of AKI

7 days

abnormal

chronic kidney disease (CKD)

Oliguria =

Anuria =

UOP < 500 Ml/24hrs (<20ml/Hr)

UOP 100 MI/24hrs

What are ten modifiable risk factors of AKI?

hypertension

hypoalbuminemia

anemia

sepsis

nephrotoxic drugs

mechanical ventilation

hypercholesterolemia

rhabdomyolysis

hyponatremia

hemolysis

What are the non-modifiable risk facts of AKI?

CKD

diabetes

acute gastroenteritis AGE

chronic liver disease

congestive heart failure CHF

renal artery stenosis

peripheral vascular disease PVD

AIDS

What are the three most common pathogenesis of AKI?

ischemia

toxic injury

sepsis