Renal Flashcards
UTIs more commonly occur in males or females?
Females
1 in how many women, by the age of 24, will have had a UTI?
1 in 3
Which bacteria causes 80% of UTIs?
E.coli
As well as E.coli, what are the other causes of a UTI? (3 + 1 very rare)
- Staphylcoccus species
- Proteus mirabilis
- Enterococci
- Candida albicans (very rarely)
If candida albicans is the cause of the UTI, in what people is it most likely to occur/what risk factors is it associated with?
Hospitalised patients with risk factors such as indwelling catheter, immunosuppression, diabetes or antibiotic treatment.
What are the three routes/classifications of a UTI occurs?
- Retrograde - ascending through the urethra into the bladder
- Blood stream (most likely in immunocompromised people)
- Direct - for example upon insertion of a catheter into the bladder, instrumentation or surgery.
Although most UTIs aren’t associated with many risk factors, what are the possible risk factors for women? (8)
- Sexual intercourse
- Atrophic urethritis & vaginitis
- Abnormalities of the urinary tract function i.e. indwelling catheter, neuropathic bladder, outflow obstruction)
- Anatomical abnormalities
- Incomplete bladder emptying
- Female diaphragm
- Immunocompromised
- Previous UT surgery
In men, what are the risk factors associated with UTIs? (5)
- Abnormalities of the urinary tract function i.e. indwelling catheter
- Structural abnormalities - urinary stones, renal tract abnormalities
- Incomplete bladder emptying
- Previous UT surgery
- Immunocompromised
How does a UTI present? (10)
- Increased urinary frequency/urgency and/or strangury (the feeling of needing to pass urine despite having just done so)
- Dysuria
- Urine that smells, is cloudy or contains blood
- Lower abdominal ache
- Non-specific malaise
- Nausea
- Cold sweats
The following are more common in elderly, frail women: - Rigors
- New onset delirium
- Fever > 37.9 (or 1.5 above baseline)
- Costovertebral tenderness
What are the signs on examination associated with a UTI/complicated UTI? (2)
- Suprapubic tenderness
2. Loin pain and fever (may be pyelonephritis)
What investigation is carried out with a suspected UTI, and what will give a positive finding?
Urine dipstick
1. Leucocyte esterase
2. Nitrite
If both positive, obviously very highly likely
If neither are positive, UTI is unlikely
If nitrite is positive, UTI is highly likely
If leucocyte esterase is positive, UTI is moderately likely
If the symptoms are present but the patient is catheterised, so urine dipstick is not possible, how should the patient be managed?
Treat with suspected UTI - it is reasonable to start on empiric antibiotics
Why should a urine dipstick not be tested in a person with an indwelling catheter?
Research studies have shown that they won’t distinguish between asymptomatic bacteriuria and a UTI
When should urine cultures be sent for, in women with a suspected UTI? (3)
In women who present for the first time with a UTI, if they have any of the following:
- Impaired renal function
- An abnormal urinary tract (for example renal calculus, vesicoureteric reflux, reflux nephropathy, neurogenic bladder, urinary obstruction, or recent instrumentation).
- Immunosuppression
In women presenting with a UTI and positive dipstick testing (or negative dipstick testing but obvious symptoms), what is the recommended treatment? (2)
*Paracetamol and/or NSAIDs (ibuprofen/naproxen)
*3-day antibiotic course - either:
- Nitrofurantoin: 50mg 4X daily or 100mg
2X daily
- Trimethoprim: 200mg 2X daily
local guidelines may indicate which is preferred based upon local resistance patterns
What is not to be recommended for treatment of a UTI? (2)
- Cranberry juice/products
- Urine alkalinising agents
(due to a lack of evidence supporting either of these options)
In women with a complicated UTI, how long should the course of antibiotics be?
5-10 days
What is different about treating a UTI in a pregnant women, compared to not pregnant? (4)
- Urine cultures must be sent in all pregnant women with a suspected UTI, before treatment and after, to check it has been cured
- If trimethoprim is prescribed, folic acid must be prescribed alongside it, if the women is in the first trimester of pregnancy
- An alternative antibiotic for use is cefalexin 500mg 2X daily (though this is more broad spectrum so NICE recommends nitrofurantoin over this)
- The course of treatment should be 7 days
In pregnant women with asymptomatic bacteriuria, what is the recommended antibiotic to use?
- Amoxicillin - 250mg 3X daily; safe during pregnancy
2. Nitrofurantoin (if amoxicillin is not suitable)
If a women with a catheter is found to have a UTI, what is the course of action and treatment plan?
- Change the catheter before treatment (if it has been in place for > 7 days)
- Paracetamol/NSAIDs
- Either nitrofurantoin or trimethoprim
If a women with a catheter is found to have asymptomatic bacteriuria, what is the course of action?
Do not treat with antibiotics, offer paracetamol and/or NSAIDs
What is pyelonephritis?
It is an infection within the renal pelvis, with or without active infection of the renal parenchyma. It is generally caused by bacteria ascending the from the lower urinary tract. Small cortical abscessed and streaks of pus in the renal medulla are often present.
What are the most common pathogens known to cause pyelonephritis? (5)
- Escherichia coli.
- Klebsiella pneumoniae.
- Proteus species.
- Pseudomonas species.
- Enterococcus species.
What are the complications of pyelonephritis? (3)
- Impaired renal function or renal failure
- Sepsis
- Pre-term labour in pregnancy
The risk of developing a complication of pyelonephritis is increased in people with what? (6)
- Severe illness
- Abnormalities of the renal tract anatomy/function
- Diabetes
- Pregnancy
- Over 65 years old
- Persistent pyelonephritis despite treatment
How is acute pyelonephritis diagnosed?
Acute pyelonephritis is diagnosed in a person with a proven UTI who has loin pain and/or fever. (There are no clinical features or routine investigations that conclusively distinguish acute pyelonephritis from cystitis).
A urine culture is normally sent for to determine the pathogen.
If a person has loin pain/fever but negative dipstick test for a UTI, what could be the other causes of loin pain? (3)
- Pelvic inflammatory disease
- Appendicitis
- Renal calculi
In people with diagnosed pyelonephritis, who can be treated in primary care, rather than be admitted to hospital? (2)
- In people who are pyrexial but have no risk factors for developing a complication from acute pyelonephritis
- In people who are apyrexial, with or without risk factors for developing a complication
Under what conditions should people be admitted to hospital with acute pyelonephritis? (5)
- People who are significantly dehydrated or unable to take oral fluids/medications
- Have signs of sepsis
- Are pregnant and pyrexial
- Frail/elderly residents of care homes who have recurrent UTIs
- Fail to improve significantly within 24 hours of antibiotics
What is the treatment for pyelonephritis, in women who are not pregnant, men and people with indwelling catheters? (1 first-line, and 1 alternative)
- Ciprofloxacin 500mg 2X daily for 7 days
An alternative = Co-amoxiclav 500/125mg 3X daily for 14 days
What is the treatment for pyelonephritis in pregnant women who do not require admission?
Cefalexin 500mg 2X daily for 10-14 days
In addition to antibiotics, what other treatment/advise is given regarding pyelonephritis? (3)
- Take paracetamol for the pain/fever
- Maintain full hydration
- Review urine culture and change medication if necessary
When is a referral for investigation of underlying abnormality recommended in acute pyelonephritis? (3)
- In women who have had 2 or more episodes
- In men following their first episode
- All people with a UTI caused by a proteus species
What is hydronephrosis?
It is the swelling of one or both kidneys due to the build up of urine
What are the common causes of hydronephrosis? (3)
The common causes are:
- Prostatic obstruction
- Gynaecological cancer
- Calculi
What are the causes of hydronephrosis within the lumen? (4)
- Calculus
- Tumour of the renal pelvis/ureter
- Blood clot
- Sloughed renal papillae (diabetes, NSAIDs, sickle cell disease/trait)
What are the causes of hydronephrosis within the wall of the urinary tract/pressure from outside the wall? (6)
- Congenital abnormalities of the urinary tract
- Stricture
- Neuropathic bladder
- Diverticulitis
- Aortic aneurysm
- Prostatic hypertrophy
How does hydronephrosis present if it is caused by an upper UT obstruction? (3)
- dull ache in the flank/loin which may be provoked by an increase in urine volume (high fluid intake)
- Complete anuria is strongly suggestive of complete bilateral obstruction
- Polyuria - due to partial obstruction as a result of tubular damage and impairment of concentrating mechanisms
How does hydronephrosis present if it is caused by a bladder outlet obstruction? (4)
- Poor stream/hesitancy
- Terminal dribbling and a sense of incomplete emptying
- Frequent passage of small quantities of urine
- Infection commonly occurs and may precipitate acute retention of urine
What may be the signs on examination of hydronephrosis?
It depends on the site of obstruction - an enlarged bladder or kidney may be felt on examination. Pelvic and rectal examination are important to determine the cause of the obstruction.
What investigations are carried out with suspected hydronephrosis? (3)
- Imaging: ultrasound (although helical/spiral CT scanning has a higher sensitivity) for detecting calculi/details of obstruction. Excretion urography identifies the site of obstruction
- Radionuclide studies: not useful in acute obstruction, but may help in longstanding obstruction
- Bloods: to assess creatinine and function of the kidneys
What is the treatment for hydronephrosis?
Surgery is the usual treatment for persistent obstruction. If the obstruction cannot be fixed surgically, an alternative solution including either; an indwelling catheter, a stent placed across the obstructing lesion or the formation of an ileal conduit may be considered.
How common is acute kidney injury (AKI) formerly known as acute renal failure?
Very common - stage 1 AKI is found in more than 15% of emergency hospital admissions. AKI with plasma creatinine >500micromol/L is diagnosed in 2 to 7.5 per 10,000 adult population per year in the UK.
What is AKI characterised by?
A decline in renal excretory function over hours or days that can result in failure to maintain fluid, electrolyte, and acid-base homeostasis
What are the three categories causes of AKI can be divided in to?
- Pre-renal
- Renal (Intrinsic)
- Post-renal
What are the pre-renal causes of AKI? (2)
- Hypovolaemia (e.g. haemorrhage, gastrointestinal losses, renal losses, burns)
- Reduced cardiac output (e.g. cardiac failure, liver failure, sepsis, drugs)
What are the renal (intrinsic) causes of AKI? (5)
- Drugs (e.g. ACE inhibitors, NSAIDs— mechanism of renal damage depends on the type of drug)
- Vascular (e.g. vasculitis, thrombosis, athero/thromboembolism, dissection)
- Glomerular (e.g. glomerulonephritis)
- Tubular (e.g. ischaemia, rhabdomyolysis, myeloma, contrast)
- Interstitial (e.g. interstitial nephritis)
What are the post-renal causes of AKI?
Obstruction (e.g. renal stones, pyonephrosis, blocked catheter, pelvic mass, enlarged prostate, cervical carcinoma, retroperitoneal fibrosis)
In addition to surgery, how else is hydronephrosis treated? (1)
- Urine drained using catheter inserted into kidney through the urethra, or directly through the skin
What are the possible complications that can occur from hydronephrosis? (2)
- Increased chances of UTI
2. Scar tissue building up in the kidneys which can reduce kidney function –> kidney failure
What is the most common cause of AKI?
Reduction in renal perfusion causing ischaemia of the renal parenchyma