Session 10- Diuretics and UTI Flashcards
what are diuretics
act on kidney to increase the producton of urine and eliminate water from the body
- reduce plasma volume and cardiac output
- reduce blood pressure
- reduce oedema
where do carbonic anhydrase inhibitors act
PCT
Where do osmotic diuretics act
pct
where do loop diuretics act
ascending loop of henle
where do thiazide and thiazide-like diuretics act
DCT
where do potassium sparing diuretics act
collecting duct
what is an example of an osmotic diuretic and hiw di they work
mannitol
increase water excretion with relatively less effect on Na+ (Water diuresis)
acts as an osmole draws water towards it. As it is filtered from glomerulus to the PCT draws water in so less is rebasorbed
what is the downside of mannitol
expand ECF, decrease blood viscosity and inhibit renin release and increase renal blood flow
- headache
- nausea
- vomiting
when would you use mannitol
acute renal failure due to shock or trauma
acute drug poisoning
decrease intracranial and intraocular pressure
what transporter do loop diretics inhibit
Na/K/2Cl- co transporter
decreased sodium reabsorbed
less chlorine is reabsorbed also tubule is less positive leading to less Mg2+ and Ca2+ being reabsorbed
what is the most potent diretuc
loop
when would you use loop diretuc
emergency
hyperkalaemia
hypercalcaemia
pulmonary oedema
side effects of loop diuretics
hypovolemia hyponatraemia hypokalemia hypomagneisaemia metabolic alkalosis postural hypotension
what diuretics are most liley to prescribed long term
thiazixe and thiazide like diuretics
how to potassium sparing and aldosterone antagonists act
increase urinary Na+ excretion
decrease urinary K+ excretion
decrease H+ excretion - can develop metabolic acidosis
example of postassium sparing
amiloride act on collecting duct and distal DCT
example of aldosterone antaginists
spironlactone
when would you use a potassium sparing and aldosterone antagonist
secondary hyperaldoteronism congestive heart failure cirrhosis nephrotic syndrome hypertensioon
pathophysiology of cystitis and pylenephritis
ascending colonisation of bacteria from urethra
bladder- cystitis
kidney- pyelonephritis
risk factors of UTI
female- short urethra neurological conditions affecting bladder emptying pregnancy abnormal renal tract impaired host disease
causative agent of UTI
escherichia coli most common
what are the infective agents of e coli
flagellar pili capsular polysaccharide haemolysin toxins
how does cystitis present- lower UTI
dysuria cloudy urine nocturia frequency urgency suprapubic tenderness pyrexia
how does pyelonephritis present (upper UTI)
high fever loin pain loin tenderness nausea vomiting
What is an uncomolicated UTI
defined as infection by a usual organism in a patient with a normal urinary tract and normal urinary function
what is an complicated UTI
> 1 factors that predispose to persistent infection, recurrent infection or treatment failure
- abnormal urinary tract
- virulent organism
- impaired host defence
- impaired renal function
- suspected pyelonephritis
how do you investigate uncomplicated UTI
if patient is non-pregnant and healthy no need for urine sample
how do you investiagate complicated UTI
mid-stream urine
clean catch in children
culture within 4 hours of collection
what does a urine sample positive for LE suggest
prescence of staph saprophyticus
how do you treat UTI
increase fluid intake regular analgesia address underlying disorders antibiotics- trimethoprim -3 day course for uncomplicated UTI -5-7 day course for complicated lower UTI
How can we treat cystitis
nitrofurantoin
trimethoprim
pivmecillinam
fosfomycin
treatment of pyelonephritis/ septicemia
use agent with systemic activity
Co-amoxiclav
Gentamicin
what are loop diuretics used to treat
severe oedema
hyperkalaemia
acute renal failure
hypercalcaemia
what is the second most common cause of community acquired UTI
S. saprophyticus
