L8 - Urinary Infections Flashcards
Acute Urinary Retention
Complete, painful inability to empty bladder.
Where bladder is catheterised <800mls drained
Chronic Urinary Retention
Patient can void but not completely consistently.
> 500ml drained
Diuresis
Increased / excessive production of urine, of loading of retained salt and water which have been retained for a week
Osmotic diruesis may be caused by a
Increased urea level.
What may cause the excessive retention of salt and water?
- Dissipation of corticomedulary concentration gradient
- caused by reduced urinary flow through LoH
- with maintenance of BF through chronically obstructed kidney.
What caused ureteric colic?
- Passage of a stone
- Occasionally by a clot
What may cause the classic loin pain associated with ureteric colic?
Local inflammation + stretching of collecting systems.
Ureter contracting to try and eject the stone.
Causes loin pain
What is septic shock?
Combination of septicaemia with hypotension.
Organ damaged in response to infection - potentially fatal.
Anuria
Passing no urine at all
Patient presenting with a history of recurrent haematuria preceding their anuria by some months may have…
Bladder cancer.
Describe Transurethral Resection Prostate
Transurethral resection of prostate.
- performed by visualising prostate through urethra and removing tissue via dissection.
- considered most effective treatment for benign prostatic hyperplasia
What may be given if a patient has a uteric stone?
Analgesia - nsaids e.e.g diclofenac can provide very effective relief of pain.
However… persistent pain can indicate obstruction
How may obstruction be managed?
May be relieved by insertion of a precutaneous nephrostomy into the kidney.
What may be the treatment for obstructed infected kidney?
Resusciation with IV fluid, analgesia, IV broadspectrum antibiotics
Give an example of an IV broad spectrum antibiotic?
Gentamicin, combined with ampicillin.
Describe some characteristics of septic shock?
Tachycardia Tachypnoea Hyperthermia Inadequate tissue perfusion (hypoxia) Oliguria Elevated plasma lactic acid level
Tachypnoea
Abnormally rapid breathing
> 20 resps.
Oliguria
Small urine output
Criteria for hypotension
Systolic BP <90mmHg
Which class of bacteria traditionally cause septic shock?
Gram negative.
May be due to gram positive bacteria or fungi.
State common gram negative bacteria?
E.Coli Klebsiella Enterobacter Serratia Proteus Psuedomonas
Describe the pathophysiology of septic shock?
Gram negative lipopolysaccharide (Endotoxin)
Activates humoral pathway.
What does the humoral pathway consist of?
Compliment Bradykinin Coagulation Macrophages MEDIATE INFLAMMATION
Patients with anuria and bilateral hydronephrosis on USS usually have?
- Usually have bilateral uteric obstruction
Could be due to BOO, locally invasive prostate cancer or bladder tumor
Describe torsion of testes
- Fetal development.
- Testes enveloped by visceral layer of peritoneum in its descent into scrotum.
- Known as bell-clapper testis
- Can easily rotate on its pedicle and so occlude blood supply.
Two categories of renal trauma
Blunt or Penetrating
Why are children’s kidneys more vulnerable?
- Proportionatly larger kidneys relative to body size.
- Less surrounding perineal fat
- Less protective muscle bulk
In terms of pain what questions should we be asking?
Site Severity Duration Constancy Radiation Aggravating factors Relieving factors
Pain in kidneys typically found…
Loin
Pain in ureter commonly found…
Loin, iliac fossa, groin or scrotum
Pain in bladder commonly found…
Suprapubically
Give an example of an Upper UTI?
Pyelonephritis
- Severe infectious inflammatory disease of renal parenchyma, calices and pelvis.
Can be acute, recurrent or chronic
Give an example lower UTI?
Cystitis
- inflammation of bladder.
Describe an uncomplicated UTI?
Urinary tract infection occurring due to appropriate susceptible bacteria, usually in non pregnant immune competent females.
Describe a complicated UTI?
Underlying condition that increases the risk of failing therapy.
Describe how a patient may come to get a complicated UTI?
- Hospital acquired infection
- Urinary tract obstruction
- Long term urinary catheter
- Stent, nephrostomy
What are the certain risk factors for complicated UTIs?
Gender: being male Diabetic Pregnant Prolonged symptoms before treatment. Renal failure. Renal transplantation. Immunosupression. History of UTIs in childhood.
Asymptomatic bacteriuria
Presence of bacteria in urine, without urinary symptoms.
Increased incidence with age >20% over 80 y/o
No benefit treating unless patient is pregnant or before a urological procedure.
Sterile pyuria
Presence of leucocytes in urine in the absence of bacteria.
Causes of sterile pyuria
Prior antibiotics Contamination with vaginal leucocytes / sterilising solution Stones Tumour TB, chlamydia Interstitial nephritis
What microbes are associated with uncomplicated UTI?
E-Coli Staphylococcus Saprophyticus (5-15%) Proteus Klebsiella Pneumoniae Enterococci
What microbes are associated with complicated UTI?
Serratia Providencia Morganella Citrobacter Enterobacter Psuedomonas Fungi e.g. candida
What are some clinical manifestations of acute uncomplicated cystitis?
Dysuria Urinary frequency Urgency Suprapubic pain Haematuria (esp in absence of vaginal symptoms)
What are some clinical manifestations of acute uncomplicated pyelonephritis?
Fever Chills / rigors Flank pain Costovertebral angle tenderness Nausea and vomiting
Where would you find the costovertebral angle?
Acute angle formed on either side of the human back between the 12th rib and vertebral column.
What organisms may cause urethritis?
Chlamydia Gonorrhoea Trichomonas Candida Herpes simplex virus Non-infectious irritants
Describe a sign of urethritis?
Sterile Pyuria
Describe a sign of vaginitis?
Discharge, itch, dyspareunia
Absence of urinary frequency.
Give examples of structural urethral abnormalities?
Stricture - narrowing of urethra, results in difficulty for urine to pass through.
Diverticulum - small bulges/ pockets that can develop in lining of intestine as you get older.
What may nitrates in urine indicate?
Urinary nitrates - Nitrites (Enterobacteriaceae)
How might the presence of WBCs in urine be confirmed?
- Urine test detects leukocyte esterase.
- This indicates presence of WBCs in urine.
- Absence of pyruria strongly suggest alternative diagnosis.
White blood cell casts in urine sample may indicate …
Upper renal tract infection
State two antibiotics commonly used for treating UTI?
Nitrofurantoin
Trimethoprim
Nitrofurantoin
Only for uncomplicated lower UTIs
- doesn’t penetrate renal tissue or reach therapeutic concentrations in blood
Trimethoprim
Uncomplicated UTI, widely distributed in tissues.
Why are Beta-Lactams used?
Generally good excretion in urine.
Safety in pregnancy.
Favourable safety profile.
State examples of commonly used beta-lactams?
Cefalexin: C difficile
Amoxicillin
Augmentin
Pivmecillinam
What is the disadvantage of amoxicillin?
> 70% of enterobacteriaeceae are resistant.
Whats a very valuable antibiotic
Ciprofloxacin
