Renal Flashcards
There is net excretion if which five things from the kidneys
Sodium, potassium, phosphate, acid and uraemic toxins
How is the 120ml/min GFR expresses clinically
ml/min/1.73m^2 body surface area
What complications come with decreasing kidney function
Anaemia, bone disease and symptoms from uraemic toxins
What is the difference between GFR and eGFR
GFR is a concept, eGFR is an estimate by measuring serum creatinine
Extremes of muscle mass
Cachexia, body builders. Amputees and liver disease
What drug makes inhibits creatinine secretion and how does this effect eGFR
Trimethoprim. Makes eGFR appear worse
Why does eGFR start to overestimate GFR as it drops
Because more creatinine is secreted by the tubules as the filtration rate lowers
What is reabsorbed in the PCT
70% filtered sodium, phosphate, glucose, amino acids
Where do loop diuretics act
Loop of henle
Where do thiazides act
DCT
Where does spironolactone act
Aldosterone antagonist acting on Na/K channels in collecting duct
Which diuretics are the most influential
Loop diuretics. 25% are reabsorbed there
What part of the juxtaglomerular apparatus detects sodium delivery to the DCT and therefore fluid delivery
The macula densa
Why do ACE-I and NSAIDS combined cause kidney failure
NSAIDS constrict afferent (prostaglandin). ACE-I dilate
How are acute potassium changes buffered
Insulin and catecholamines
Blocking aldosterone has what ion affect
Low sodium and high potassium. Metabolic acidosis.
Where is vitamin D hydroxylated
25 hydroxylated in liver, 1 hydroxylated in kidney
What is the active form of vitamin D
Calcitriol
What are calcium and phosphate levels like in kidney disease
Cause of vit D. Low calcium but as kidney excretes phosphate. Phosphate is high.
Daily fluid intake for adults
1.5-2L for relatively sedentary lifestyle
Name some methods of fluid loss
Vomitting, diarrhoea, urinating, sweating, burns and bleeds
Symptoms of hypovolaemia
Thirst and dizziness
Symptoms of hypervolaemia
Breathlessness and leg oedema
Results of lab tests in hypovolaemia
High Cr, Hb and Hct
Lab test results in hypervolaemia
Low or normal Cr, Low Hb and Hct
Signs in hypovolaemia
Tachycardia, reduced BP,JVP, dry tongue, reduced weight and low urine output
Abnormal signs in hypervolaemia
High or normal BP, High JVP, increased weight. normal pulse
What is euvolaemia
Where there are no signs or symptoms of hypo or hypervolaemia
What are postural BP readings
Where BP is taken standing
How is skin turgor measured
Skin with decreased turgor remains elevated after being pulled up and released
What is the central venous pressure
pressure within the thoracic vena cava before it enters the right atrium
What is the third space
The non functional area between cells where fluid doesnt normally collect
When can it be difficult to assess fluid
In obese patients
Patients at risk of hypovolaemia
Elderly, short bowel syndrome with bowel obstruction and colostomy bag. On diuretics.
Patients at risk of hypervolaemia
Acute and chronic kidney disease, heart and liver failrue
What is crystalloid IV fluid
Small molecules which pass into the extravascular space. Containing salt makes it stay longer in intravascular space.
What is colloid IV fluid
Large molecules which remain in the intravascular compartment. Increase the oncotic pressure so expand the intravascular volume
Name a colloid IV fluid
Gelofusine (contains gelatine)
Name diuretics
Furosemide, bumetanide, spironolactone, metolazone
Hypovolaemia treatment
Fluids and treat reversible cause
Hypervolaemia treatment
Diuretics and treat reversible cause
What is the urine output like in chronic kidney patients
Oligouric or anuric
Oligouric meaning
Low urine output (below 400-500ml)
Anuric meaning
No urine output
At what stage of chronic kidney disease does normal urine output stop
Stage 5 <15
What to consider when treating oligouric or anuric CKD patients
Urine, dialysis, refluid restriction, reassess fluid status
What shouldnt you do when treating oligouric or anuric CKD patients
Prescribe multiple bags without assessment or prescribe Hartmann’s solution
Why shouldnt you give Hartmann’s solution fluid to oligouric or anuric CKD patients
As contains 5mmol potassium
What can be causes of rising Cr in CKD
Too many diuretics, extravascular hyper but intravascular hypovolaemia. Progression of CKD
The three diagnostic criteria for AKI (need 1)
26mmol/L rise in 48hrs, >50% rise from best in last 6 months, low urine output (<0.5ml/kg/hr) for 6 consecutive hours
What do you suspect when someone has been lying down for hours
Rhabdomyolysis so check creatinine kinase
Common prerenal AKI causes
Low BP, Low blood volume, heart failure, liver cirrhosis. Dehydration.
Common renal AKI causes
Glomerulonephritis, acute tubular necrosis, acute interstitial nephritis
Common postrenal AKI causes
UT obstruction, kidney stones, obstructed catheter, cancer of the bladder, ureters or prostate
Which investigations are done in AKI
FBC, FUB USS, urine dip stick
Why is an ultrasound needed in AKI
To ensure no postrenal blockage, as if you gave fluids that would lead to oedema
What would be present on a urine dipstick for pyelonephritis
Haematuria, proteinuria
How is hyperkalaemia seen on XRay
Tall pointed T waves and small P waves
Hyperkalaemia management
Insulin+dextrose, calcium gluconate, IV fluid and salbutamol
What is a wet AKI patient and how are they treated
Pulmonary oedema and heart failure, treated with diuretics and treat the original cause
How are dry AKI patients treated
They are given fluids
Name risk factors for AKI
Age, comorbidiites, reasons for admission and nephrotoxic drugs
Which drugs are nephrotoxic
Chemotherapy drugs and some diuretics
What are uremic symptoms
Confusion, itchiness of skin, uremic pericarditis
What % of the body is a major burn in an adult
30%
What % of the body is a major burn in a child
10%
How is the body split up for burns
11 9%s. Head and neck, arm, arm, leg(=2), leg(=2), chest(=2), back(=2) and genitals is 1%
Define glomerulonephritis
inflammation of the glomerulus
How does nephritic syndrome present
Hypertension and abnormal kidney function
How does chronic glomerulonephritis present
features of CKD
How does nephrotic syndrome present
hyperalbuminaemia and hyperlipidaemia
What test do you think of when you think glomerulonephritis
URINE DIP STICK
Who is disproportionally affected by glomerulonephritis
Caucasians in their 50s, 60s and 70s
Three functions of the urinary tract
To collect urine continually produced by the kidneys, to collect and store urine safely, to expel urine when socially acceptable
Between which two levels do the kidneys lie
T11 and L3
At which level does the renal artery come off the aorta
L1
How much urine is produced by the kidneys each day
2-3L
How does urine move
By peristalsis
How is reflux of urine prevented
Valvular mechanism at the vesicouteric junction
What are the three uteric narrowings
Uteropelvic junction, pelvic brim and where the ureter enters the bladder
Which nerve provides the parasympathetic supply of the bladder
Pelvic nerve
Which nerve provides the sympathetic supply of the bladder
Hypogastric plexus
Which nerve provides the somatic supply of the bladder
Pudendal nerve
What is onufs nucleus responsible for
Guarding reflex via the pudendal nerve
Normal adult bladder capacity
400-500ml
Describe the storage state of the bladder
Receptive relaxationm, detrusor muscle relaxed and external urethral sphincter contracted
Describe the micturition state of the bladder
Voluntary control from cortex and PMC detrusor muscle contraction, external urethral sphincter relaxed
What is the normal function of the lower urinary tract
To convert the continuous process of urine excretion into an intermittent process of elimination
Name LUT storage symptoms
Frequency, nocturia, urgency and urgency incontinence
Name LUT voiding symptoms
Hesitancy, straining, poor/intermittent stream, incomplete emptying, post micturition dribbling, haematuria and dysuria
Define dysuria
Painful or uncomfortable urination
A diagnosis of BPH is based on which findings
Histological
A diagnosis of BPE is based on which findings
DRE
A diagnosis of BOO is based on which findings
Urodynamic proven obstruction
What does DRE stand for
Distal rectal examination
What is the histological definition of BPH
Increase in epithelial and stromal cell numbers in the periurethral area of the prostate
What is the dynamic component of benign prostatic obstruction
Alpha 1 adrenoceptor mediated prostatic smooth muscle contraction
What is the static component of benign prostatic obstruction
The volume effect of BPE
Factors which can affect BPH development
Androgens, castration and androgen withdrawal
What is IPSS
A system used to objectively give severity of symptoms in lower UT, domains are scored out of 35
What questions do you ask during a DRE
Can you feel the finger? Can you close the sphincter?
What does TRUSS stand for
Trans rectal ultrasound scan
What is a TRUSS used for in LUTS
Investigating the size
When is flexible cystoscopy used in LUTS
If infection, stones, haematuria or recent onset storage symptoms
What is the normal flow rate for an hour
20ml
Name two causes of reduced flow rate of urine
Obstruction within the lower UT and detrusor muscle underactivity
What can cause a high post void residual volume
Detrussor muscle underactivity
What are two consequences of raised post void residual volume
Hydronephrosis and elevated creatinine
Complications of BPE
Symptom progression, infections, stones, haematuria, urinary retention, interactive obstructive uropathy
Define acute retention of urine
Sudden onset of inability to retain urine
Is precipitated or spontaneous retention more likely to recur
Spontaneous retention
What is ISC
Intermittant self catheterisation
What is TWOC
Trial without catheterisation
The bladder is normally emptied when it reaches which volume
300ml
Long term options for interactive obstructive uropathy
Turp or indwelling catheter
Define diuresis
Increased or excessive production of urine
What are bladder stones
Aggregates of minerals that occur in the bladder due to obstruction of flow
What is hydronephrosis
Dilation of the renal pelvis or calyces
Name an alpha adrenergic antagonist
Tamsulosin
How do alpha blockers act in prostatic disease
Reduce the tone of the sphincter
Name a 5 alpha reductase inhibitor
Finasteride
How do 5 alpha reductase inhibitors work in prostatic disease
Inhibit conversion of testosterone to the more active dihydrotestosterone
What is the acronym for surgery indications in prostatic disease
RUSHES
What does RUSHES for prostatic surgery stand for
Retention, UTIs, Stones, Haematuria, Elevated cr, Symptom deterioration
Treatment for interactive obstructive uropathy
Short term: Catheter. Long term: TURP
Define obstructive uropathy
Functional or anatomic obstruction of urine flow at any level of the urinary tract
Define supravesical obsstruction
Above the level of the bladder
Define infravesical obstruction
Below the level of the bladder
What does the severity of LUTS obstruction depend on
Extent of obstruction, unilateral or bilateral and whether it has been relieved or not
What is the equation for renal blood flow
(Aortic pressure-renal venous pressure)/ renal vascular resistance
Name a renal metabolite which causes vasoconstriction and therefore further damage in LUT obstruction
ANP
What changes result from obstruction in the kidney
Biochemical, immunoloic, haemodynamic and functional changes
Why do you get renal colic in obstruction
Spinothalamic C fibers are excited by utereral wall tension
Which scans are used for LUT obstruction
Ultrasound first and then if obstruction seen CT scan for more information
What is the first line imaging for suspected ureteral obstruction
CT
What does one sided loin pain suggest a problem with
Ureter
What does bilateral loin pain suggest a problem with
Bladder, prostate or urethra
What is a nephrostomy
Catheter which comes directly out of the kidney
Treatment for LUT obstruction in the pregnant
Ultrasound guided percutaneous drainage
Common cause of blocked ureter in the young
Kidney stone
What is pathologic postobstructive diuresis
Where there is impaired concentrating ability of sodium absorption as there is less sodium transports in thick limb, more ANP and poor response to ADH
Short term consequences of LUT obstruction
Renal failure and post obstructive diuresis
Who is most likely to get urolithiases
Men who are 30-50
What is classed as the upper urinary tract
Kidneys and ureters
Congenital anatomical causes of stones
Horseshoe, duplex, PUJO, spina bifida
Acquired anatomical causes of stones
Obstruction, trauma and reflux
Urinary causes of stones
Metastable urine, calcium, oxalate, urate, cysteine, dehydration.
Why does infection cause stones
It changes the acid/base balance of the urine
What constituent suggests the stones have come from infection
Struvite, 5-10%
Which stones cant be seen on XRay
Uric acid
What is a cause of cyteine stones
Congenital ‘COLA’- Cystine, ornithine, lyseine and arginine
How can stones be prevented
Overhydration, normal diet (dairy and protein), low salt, reduced BMI, active lifestyle. CHECK CALCIUM AND PTH
How can you prevent uric acid stone formation
Deacidification of the urine to 7-7.5
How can you prevent cysteine stone formation
Alkalinisation through overhydration. Cysteine binders and genetic counselling
Stone symptoms
Asymptomatic, loin pain, renal colic, recurrant UTIs and symptoms, haematuria
What are UTI symptoms
Dysuria, strangury, urgency and frequency
What is strangury
Blockage or irritation of base of the bladder, leading to severe pain and desire to urinate
What causes renal colic
Upper urinary tract obstruction
Where is the loin
Above the pelvis but below the ribs
Uteric colic investigation
NCCT-KUB
Red flags in renal colic
Fever, infection signs
What does haematuria suggest
Stones
Differential diagnosis for renal colic
Ruptured AAA (if over 50, most liikely), diverticulitis, appendicitis, ectopic pregnancy, ovarian cyst torsion, testicular torsion, MSK
What does CT stand for
Computerised tomography
Cons of CT
No functional information and there is radiation
When looking at a NCCTKUB what should you look for on the kidneys
Perinephric tissues, cortical thickness, hydronephrosis+- hydroureter, stones
