Urinary Tract Infection - Overview (signs and symptoms, pathophysiology, causes and treatment)

hello in this video we're going to talk

about urinary tract infections this is

an overview and introduction it is

important to revise the anatomy of the

urinary system specifically the urinary

tract let us begin by looking at the

male here we have the kidney coming off

the kidney is the ureter which carries

urine into the bladder here we have the

glans penis a penis and the urethra

below the bladder we have the prostate

coming past the prostate and into the

urethra is the seminal vesicles an

important part of semen production then

we have the vas deferens the actual tube

that runs from the testes and the testes

is where sperm is produced the female

anatomy is very similar except

importantly they have a shorter urethra

with a shorter urethra means that they

are an increased risk of developing UTI

causative agents of UTI are mainly

Ecoline in 90% of cases others include

interior bacteria produce mirabilis and

Klebsiella pneumoniae they essentially

enter the urethra and colonize the area

or bladder because of a variety of

reasons and risk factors and eventually

can cause a urinary tract infection a

UTI the bacteria will cause a lower UTI

usually and this can be either cystitis

which is infection of the bladder

prostatitis which is infection of the

prostate plan and urethritis which is

infection of the urethra infection of

the lower urinary tract can progress and

cause an upper urinary tract infection

this is where infection affects the

kidneys this is called pyelonephritis

pyelonephritis is serious and can cause

acute renal failure

interestingly as we know urinary tract

infections are more common in women and

up to one-third of women with symptoms

of a urinary tract infection have

actually negative midstream urine

samples revealing any form of infection

that was a side note but anyway how does

a UTI occur let's look at the

pathophysiology here again is the kidney

the ureter the bladder the urethra here

we have the inferior vena cava and the

renal vein comes from the kidney and

enters the inferior vena cava behind the

inferior vena cava we have the

descending aorta which will supply the

kidneys with the branching renal artery

so what initially happens one is

contamination bacterial contaminates the

lower urinary tract because of certain

risk factors let's just say the bacteria

is e-coli because it is the most common

in 80% of cases they initially colonize

the urethra and the bladder this

triggers an inflammatory response in the

lower urinary tract neutrophils are then

recruited to this area as you can see in

the bladder you have bacteria and you

have neutrophils the bacteria multiply

and they are able to evade the immune

system because of certain verlan factors

ecoli for example can bind to cells in

the lower urinary tract and hide from

immune cells the bacteria can form

biofilms a biofilm is any group of

microorganisms in which they stick to

each other and often these

microorganisms adhere to surfaces and it

allows them to survive if this urinary

tract infection progresses and left

untreated or if the patient is

immunocompromised has risks risk factors

the bacteria can ascend towards the

kidneys and then colonize the kidneys

causing an upper urinary tract infection

and then from here if left untreated the

bacteria can spread into circulation via

the renal veins causing worse case

septic shock

a big risk factor for developing urinary

tract infections especially in females

is urinary catheterization same thing

happens the catheter can introduce

infection straight into the bladder if

not done hygienic ly the bacteria

colonizes the bladder initiating an

immune response neutrophils enter

further promoting inflammation

fibrinogen accumulates on the catheter

providing an ideal environment for the

attachment of Europe pathogens that

Express fibrinogen binding proteins

after these bacteria initial attachment

to the fibrinogen coated catheters the

bacteria can multiply and they can again

form biofilms promote epithelial damage

and concede an infection of the kidney

and so the same story occurs in

pregnancy urinary tract infections are

common catheterization will almost

always result in a urinary tract


the reason being is not only is the

urethra shorter in women but during

pregnancy progesterone relaxes smooth

muscle causing stasis of urine which

allows for colonization especially up to

the kidneys during pregnancy it is

important to perform urine analysis

because not only our urinary tract

infections more common but are also

asymptomatic untreated urinary tract

infections during pregnancy can have

consequences for the growing infant in

utero so now let's talk about risk

factors for UTIs

these include pregnancy being female

menopause because it's dry in the vagina

and the urethra

sexual intercourse condoms

catheterization urinary tract

malformation and urinary stones are also

risk factors

signs and symptoms of UTI depend on

where the infection is if it is lower

urinary tract infection or if it's an

upper urinary tract infection upper

being the more severe lower urinary

tract infections caused dysuria pain

upon urination frequency hematuria blood

in urine suprapubic discomfort and a

burning urgency sensation with urination

the urine is often described as being

cloudy and having an offensive smell

upper urinary tract infections can have

the same types of symptoms but

classically mal ace fever

Rygel's vomiting and loin flank pain

radiating to the back there can be signs

of shock if the infection is more severe

the classic triad for upper urinary

tract infections or high-low nephritis

is vomiting flank loin pain and fever

another way to categorize UTI is either

being complicated or uncomplicated to

put it simply uncomplicated UTI the

renal tract and function are normal with

complicated there is decreased renal

function based on investigations and

symptoms and potentially is a cup is

accompanied by an abnormal urinary tract

let's go through an algorithm of

managing urinary tract infection

it is important to remember that if

there is discharge or each with signs of

UTI perform a genital examination with

swab to check for a sexual transmitted

infection STI a characteristic of STI is

having discharge and a fishy smell of

within the mucus other investigations

that are performed importantly a urine

dipstick which will show which will show

hematuria proteinuria positive nitrates

and the presence of urine microscopy can

be formed as well as a urine microscopy

culture sensitivity bloods include full

blood count to check for infections CRP

eita HCG serum to check for ectopic as a

differential diagnosis especially in a

young female adult for UTI if the

urinary dipstick is positive treat with

empirical antibiotics if the dipstick is

negative but you still suspect UTI send

for microscopy culture sensitivity using

the urine sample the diagnosis of a UTI

is having a bacterial growth on a

culture plate of more than 10,000

culinary colony forming units per mil as

mentioned urinary tract infections are

common in females and so if a female

patient presents with an uncomplicated

UTI she's most likely able to go home

discharged with oral antibiotics the

treatment of UTI is essentially

empirical antibiotics for lower urinary

tract infections it's typically oral

antibiotics a three to seven day course

consisting of either trimethoprim nitro

Aafrin Troy or amoxicillin upper UTI are

generally more serious and require IB

antibiotics initially until the fever

has settled and then moving on to oral


course of antibiotics are generally

longer with upper urinary tract


finally it is important to know when to

refer to a renal specialist or urologist

refer to a urologist if there is failure

of the patient to respond to antibiotic

treatment if there is recurrent UTI

which is defined as having three or more

in a one year in one year refer to a

urologist if a man a men have symptoms

of an upper urinary tract infections and

this is because it is very uncommon for

men to develop upper UTI and potentially

it could be a result of a more sinister

anatomical abnormality finally refer to

your ologist also if there is

significant human shariah finally

preventive measures for UTI include

drinking more water antibiotic

prophylaxis especially for females with

recurrent UTIs and cranberry juice

although there are arguments for for and

against this