GU Flashcards
What is the function of calcitriol?
- Increased calcium and phosphate absorption from the gut
2. Suppression of PTH
What do people with CKD commonly present with?
hyperparathyroidism
How does CKD cause hyperparathyroidism?
Calcitriol deficiency, calcitriol supresses PTH therefore deficiency –> hyperparathyroidism
What is PTH secretion triggered by?
Low serum Ca
What are 3 ways that PTH increases serum calcium?
- Increased bone resorption
- Increased reabsorption of calcium at the kidneys
- Stimulates 1-hydroxylase –> 1,25 dihydroxyvitD –> increased calcium absorption from the intestine
What hormones are secreted from the posterior pit gland?
- ADH
2. Oxytocin
What is the function of ADH?
Acts on the CD, increases the insertion of aquaporin 2 channels –> H2O retention
What factors stimulate the release of renin?
- Sympathetic stimulation
- Decreased BP
- Decreased Na detected by the macula densa
What are the functions of ANP?
- Renal vasodilator
- Inhibits aldosterone
- Closes ENaC –> decreased Na reabsorption
Where does aldosterone act on?
CD
What is the action of aldosterone?
- Increases ENaC and H+/K+ pumps –> increased Na+ absorption and K+ secretion
- This causes H2O retention and increased BP
What anatomical structures make up the lower UT?
Bladder –> bladder neck, prostate gland –> urethra –> urethra and urethral sphincter
What are the functions of the bladder?
- Storage of urine
- Converts continuous process of excretion to an intermittent, controlled volitional processes
- Prevents leakage of stored urine
- Allows rapid, low pressure voiding
Describe the action of the detrusor muscle.
Storage - relaxes
Voiding - contracts
Describe the action of the urethral sphincter
Contracts during storage and relaxes during voiding.
What lines the bladder?
Pseudo stratified urothelium lines the bladder
Explain the physiology of micturition
- Bladder fills and stretch receptors are stimulated
- Afferent impulses stimulate Parasympathetic action of detrusor muscle –> contracts
- Urethral sphincters relax, mediated by the inhibiton of neurones
- PAG is stimulated.
Describe the fluid constituent in the body.
ICF – 28l
ECF – 14l
What is the ECF broken into?
Interstital –> 11l
Plasma –> 3l
What is the total body fluid?
42L
How much fluid is
Intravascular?
Extravascular?
Intravascular –> 3L
Extravascular –> 39l (ICF+interstitial)
What is the function of the prostate?
Secretes proteolytic enzymes into the semen which break down clotting factors in the ejaculate
What zone does prostate cancer usually affect?
peripheral zone.
What is a major worry for prostate cancer?
METASTASIS
To bone and lymph nodes.
What investigations would you do in suspected prostate cancer?
- Serum –> PSA
- Urine –> PCA3 and gene fusion products
- History of LUTS
- Trans-rectal LUTS
- Prostate biopsy
- DRE – Hard, irregular and craggy
What are some other causes of raised PSA?
- Benign prostate enlargement
- UTI
- Prostatitis
What is the gleason score?
A score in prostate cancer, the higher the score the more aggressive it is.
What is the treatment for localised prostate cancer?
- Observation
- Radical prostatectomy
- Radiotherapy
- Adjuvant hormones
What is the treatment for metastatic prostate cancer?
Palliative treatment e.g. hormone therapy – androgen deprivation
What is an advantage for prostate cancer screening?
screening can lead to early diagnosis/early treatment and so cure or effective palliation
What are the disadvantages of prostate cancer screening?
Uncertain natural history, screening leads to overdiagnosis and over treatment
What is acute kidney injury?
Causes raised creatinine and reduced urine output
What are the risk factor of AKI?
- Increasing age
- CKD
- HF
- Diabetes mellitus
- Nephrotoxic drugs e.g. NSAIDs and ACEi
What are the prerenal causes of AKI?
- Hypertension
- Heart failure
- Nephrotoxic drugs
What are the renal causes of AKI?
- Nephrotoxic drugs
- Vasculitis
- AI
- Acute tubular necrosis
- Glomerulonephritis
What is a major complication of AKI?
Hyperkalemia which can lead to arrhythmias
How would you prevent Hyperkalemia in AKI?
- Give calcium gluconate to protect the myocardium
2. Give insulin and dextrose
How does insulin prevent kyperkalemia in AKI?
Drives K into cells and dextrose is given to rebalance the sugar.
What investigations should you perform in a patient with suspected AKI?
- Check K
- Bloods, creatinine, U +E
- Urine output
- Auto-antibodies
What is CKD?
A long term condition where the kidneys function is compromised and may get progressively worse.
What are the signs of CKD?
- Proteinuria
- Haematuria
- Impaired eGFR <60ml/min
- Rise in serum Urea/creatinine
- Anaemia –> reduced EPO
- Bone disease
- Polyneuropathy
- CV disease
- Erectile dysfunction
- Raised PTH
What are the causes of CKD?
- Diabetes mellitus
- Hypertension
- Atherosclerotic renal vascular disease
- Congenital e.g. PKD
- UT obstruction
What is the appropriate management of CKD?
- Treat underlying cause
- Slow deteroriation of kidney function e.g. maintain Bp
- Reduce CV risk e.g. statins, smoking cessation
- Treat complications e.g. anaemia
- ESRF –> dialysis or transplant
What are the causes of raised UT pressure?
- Stone in lumen of UUT
- Tumour in the wall
- LUT outflow obstruction; BPH, Tumour and stone
- Bladder obstruction
What are the 4 causes of urinary tract colonisation?
- Diseases that require chemo or steroids e.g. diabetes and immunodeficiency
- Stones or tumour in the lumen of the UT
- Poor bladder emptying
- Catheterisation
What would be seen in electron microcsopy in a patient with minimal change disease?
Fused podocytes
What is the treatment for minimal change disease?
Steroids
What is an example of a loop diuretic and how does it work?
Furosemide –> acts on Na+/k2+/2Cl- transporter (NKCC2)
What are 3 potential side effects of Furosemide?
Hypokalemia, hypotension and dehydration
What is a potassium sparing diuretic and what does it act on?
Spironolactone –> works on RAAS rather than ion channels.
When would spironolactone be given?
In someone with poor K control.
What is incontinence?
Lack of voluntary control over urination or defecation.
What is the trend in incontinence?
More common in men as men have a bladder neck and a stronger urethral sphincter then women.
What information can you get from a bladder diary?
- Frequency
- Volume
- Functional capacity
- Incontinence
What are the 3 types of incontinence?
- Stress – associated with coughing and sneezing
- Urgency
- Mixed – stress + urgency
- Continuous – due to fistula
What is the cause of Stress incontinence in men and women?
In men - neurogenic or iatrogenic (prostatectomy)
In women - secondary to birth trauma
What is the treatment for female stress incontinence?
- Pelvic floor physio
- Duloxetine (concerns over SE’s)
- Surgery
What is the treatment for male stress incontinence?
- Artificial sphincter
2. Sling
What is an overactive bladder?
Urgency and frequency in the presence of local pathology that would account for these symptoms.
What is the treatment of an overactive bladder?
- Behavioural E.g. limit caffeine
- Pelvic floor physio
- Muscarinic antagonists
- Beta 3 agonists
- Botox
- Cystoplasty
What is the role of PMC/PAG in micturition
Coordination and completion of voiding.
Which group’s are at risk of hypervolemia?
- AKI patients
- CKD patients
- Heart failure patients
- Liver failure patients
Describe the presentation of Hypervolemia?
- HR is normal, BP normal or high
- JVP is high
- Tissue turgor is normal
- Urine output is normal
- Weight is increased
What are the symptoms of hypervolemia?
shortness of breath and peripheral oedema
What is the effect on
creatine
Hb
haematocrit
in hypervolemia?
All reduced
How do you manage hypervolemia?
- Diuretics e.g. furosemide
- Fluid restriction
- Treat reversible causes
What are the reasons for a rising creatinine?
- Aggressive diuretics
- Extravascular hypervolemia but intravascular hypovolemia
- Progression of CKD
What are the signs of hypovolemia?
- Tachycardia and Hypotension
- Urine output reduced
- Tissue turgor is reduced
- Jugular venous pressure is low
- Weight is also reduced
What are the symptoms of hypovolemia?
Thirst and dizziness
What is the effect on
Creatinine
Haematocrit
Hb
in hypovolemia?
All raised
Which groups are at risk of hypovolemia?
- Elderly
- Ileostomy patients
- Short bowel syndrome
- Bowel obstructions
- Those taking diuretics
Where may fluid accumulate in hypovolemia?
- Pulmonary oedema
- Pleural effusion
- Ascites
- Bowel obstruction
- Intra-abdo collection
What is the management of hypovolemia?
- Oral fluid
- IV fluid if very ill
- Treat reversible causes
What are 3 examples of isotonic solutions?
- 5% Dextrose
- 0.9 NaCl
- Hartmann’s solution
Describe the movement of Crystalloid fluid
Intravascular to extravascular e.g. Gelofusine
Small molecules can pass through the CM.
What is haematuria?
Blood in urine
What are the causes of haematuria?
- Kidney tumour, trauma, stones and cysts
- Ureteric stones or tumours
- Bladder infection, stones or tumours
- BPH or prostate cancer
A patient presents with haematuria, what tests should you order?
- Urinalysis
- Urine cytology
- Abdo US and Abdo CT
- Cystoscopy
What is renal colic?
A pain you get when urinary stones block part of your urinary tract (Kidneys, ureter, bladder and urethra)
What are the symptoms associated with renal colic?
- Colicy pain
- Nausea and vomiting
- Pain during urination
- Severe low abdo or groin pain
- Urinating less frequently
What are the causes of renal colic?
- UT stones
- UTI
- Pyelonephritis
What investigations would you do for renal colic?
- Bloods inc, calcium, phosphate, urate
- Urinalysis
- MCS MSU
- NCCT-KUB – gold standard
What is the treatment for Renal colic?
- Analgesia e.g. NSAIDs – diclofenac
- Anti-emetics
- Check for sepsis
- Treat underlying cause.
What are the functions of the kidney?
- Filters and exretes waste products from the blood
- Regulates BP
- Retains albumin
- Reabsorption of Na, Cl, K, glucose, H2O, Amino acids
- Synthesis EPO
- Converts 1-hydroxyvitD to 1.25-dihydroxyvitD
What is the equation for GFR?
Um x urine flow rate / Pm
- Um = concentration of marker in urine
- Pm = concentration of substance in plasma
What is a typical GFR?
120ml/min
What is used to estimate GFR?
Creatine
What are 3 features of a good marker substance?
- Not metabolised
- Freely filtered
- Not reabsorbed/secreted
What is the affect of afferent arteriole vasoconstriction?
Decreased GFR
What is the affect of efferent arterial vasoconstriction?
Increased GFR
Where does the bulk of reabsorption happen in the kidneys?
PCT
What are 7 things absorbed at the PCT?
- Sodium
- Chlorine
- K
- Glucose
- Water
- Amino acids
- Bicarb
What is fanconi syndrome?
failure of the nephron to absorb essential ions. Sugar and AA are therefore present in the urine.
What is the signs of fanconi syndrome?
- Sugar in the urine
- Acidotic due to bicarb in the urine.
- Rickets/ osteomalacia
What are the causes of fanconi syndrome?
- Myeloma
2. Cystinosis
Why do we have a countercurrent multiplier system?
Generates hypertonic medullary interstitium for H2O Reabsorption
Na+ moves out of the ascending limb which increases medullary osmolality –? H2O follows
Describe tubuloglomerular feedback
Macula Densa cells of the DCT lie between the AA and EA. They detect NaCl and use this as an indicator of GFR.
What happens when the macula densa detect’s raised NaCl
AA Constriction
What happens when the macula densa detects lowered NaCl
Renin secretion
What two cell types exist in the CD?
- Principal
2. Intercalated
What does aldosterone do?
Aldosterone regulates sodium reabsorption
How can aldosterone cause hypokalemia?
- Aldosterone secretion causes increases sodium reabsorption
- Sodium reabsorption leads to K secretion therefore Hypokalemia
How do NSAIDs effect GFR?
NSAIDs inhibit prostaglandins –> so lead to AA vasoconstriction = Reduced GFR.
How do ACEi effect GFR?
ACEi cause EA Vasodilation = reduced GFR.
What factors govern renal K?
- Na+
- Aldosterone
Sodium is responsible for volume control
What hormones increase Na reabsorption?
- Aldosterone
2. Angiotensin 2
What can decrease Na absorption?
ANP
What is the function of EPO?
Stimulates bone marrow to allow for RBC maturation.
What is benign prostatic hyperplasia?
Prostate enlargement
What is PSA?
a glycoprotein secreted by the prostate into the blood stream
What are the symptoms of Benign prostatic hyperplasia?
- Increased frequency of micturition
- Nocturia
- Hesitancy
- Post-void dribbling
What is the treatment of Benign prostatic hyperplasia?
- Mild symptoms – watchful waiting
- Alpha 1 antagonists e.g. tamulosin
- 5-alpha reductase inhibitors
How does Tamsulosin work?
By relaxing the smooth muscle in the bladder neck and prostate so increases urinary flow, improving obstructive symptoms.
How do 5-alpha reductase inhibitors work?
By blocking the conversion of testosterone to dihydrotestosterone (the androgen responsible for prostatic growth)
What investigations should be done in benign prostatic hyperplasia to rule out carcinoma?
- IPSS prostate score questionnaire
- DRE
- PSA to rule out prostate cancer
What is the treatment for prostate carcinoma?
- Radial prostatectomy or radiotherapy
- Remove the androgenic drive e.g. bilateral orchidectomy