Urinary Obstruction/Altered Voiding Flashcards
What’s the common presentation (signs and symptoms) of altered voiding?
Incontinence Urgency Altered frequency Nocturia Poor stream/hesitancy Dysuria Retention Incomplete emptying Terminal dribbling
What’s parts of the body are included in LUT?
Bladder
Prostate
Urethra
Define urinary incontinence
Involuntary loss of urine in sufficient amount, or frequency to constitute a social and/or health problem
What can urinary incontinence lead to?
Morbidity/Institutionalisation
Impaired quality of life
Skin breakdown - pressure sores
What locations throughout the body are urinary tract obstructions likely to occur?
Blockages - kidney/urethra
Neuro - brain/spinal cord damage
Lower urinary tract, bladder, prostate, urethra
What are the 6 different types of incontinence?
Stress incontinence (great pressure inside bladder - middle aged women) Urge incontinence (overactive bladder - most common >50) Overflow incontinence (detrusor failure/chronic retention) Functional incontinence (doesn’t involve LUT - psychological/cognitive) Continuous incontinence Childhood incontinence (bed-wetting)
Outline the investigation, examination and management of a patient with URINARY INCONTINENCE
History important (medical Hx, precipitating events, pad usage) Examination: abdomen, genitalia, digital rectum exams Investigations: MSU, dipstick, microscopy, cytology, FBC, U&Es, frequency volume chart, urodynamics
What’s urodynamics and outflow cystometry?
Urodynamics is the study of pressure and flow during storage, transport and expulsion of urine in the LUT - detrusor function measured at inflow and outflow to record urine flow rate/residual urine
Outflow cystometry - urethral catheter into the bladder and transducer into the rectum then record the pressures in bladder and rectum when bladder is emptied. Bladder - rectum pressure = detrusor muscle function
In both can fill bladder with/without contrast
What may be causes of urinary retention/obstruction?
Benign prostatic hyperplasia Prostate cancer Prostatitis Haematuria causing clots (bladder cancer?) Tumours Stones Structural/physical/neurological
What’re the investigations, examinations and management for a patient with BPH?
International prostate symptom score classifies the symptoms
Examination: abdominal, digital rectal
Investigation: transrectal ultrasound, prostate-specific antigen
Management: alter lifestyle, doxazosin, transurethral resection of prostate
What are the common risk factors and causes of urinary tract stone formation?
Age (20-30yrs), fluid intake, diet, BMI, geography/climate
Can cause infection, chronic inflammation, malignancy
Blockage and back pressure can lead to renal failure
How are stones formed?
Crystalline growth on organic scaffold
Collisions of small crystals in urine aggregate into small stones
Crystals grow as urine supersaturated with salt and minerals - for crystal to grow it must be trapped within urine in the tract (stasis - more likely in retention)
What are the two most common types of stone?
Calcium Oxalate and Struvite
What’s a struvite stone?
Form in alkaline urine containing ammonia - caused by infection of urea-splitting bacteria
Precipitation of Mg2+, NH3, PO4
What’s the common presentation of urinary tract stones?
Investigation?
Loin to groin pain (ureteric colic)
Haematuria
Vomiting
Irritative voiding
Investigation: history, urine dipstick, urine microscopy and culture, imaging
Serum calcium and urate important
Why would you need to remove a urinary stone and what procedures allow this?
If pain/fail to pass, recurrent infection, renal impairment, obstruction, bleeding, increasing in size
Fragmentation: extracorporeal shockwave lithotripsy uses ultrasound shockwave to fragment into pieces small enough to pass
Ureteroscopic removal: ureteroscope via urethra and bladder, stones can be broken up by a laser and stent inserted to allow stone fragments to drain
Percutaneous nephrolithotomy: large stones that kidney can’t pass: kidney punctured using Xray/ultrasound guidance
What’s overflow incontinence associated with?
Chronic retention (prolonged problems with emptying)
Most common in males and occurs at night
Enlarged prostate, bladder stones
What’s urge incontinence associated with?
Overactive bladder - need to go immediately
Most common cause >50 years of age, usually idiopathic (maybe infection, tumour, stones, PD, dementia, stroke)
What’s stress incontinence associated with?
More commonly females (weakened pelvic floor muscles after child birth)
Pressure inside bladder is greater than strength of urethra to stay closed
Involuntary urine leakage on effort/sneezing/coughing
What will spinal cord transection above and below T12 lead to?
Above: reflex bladder, automatically empties as it fills
Below: flaccid bladder, detrusor paralysis so fills until abnormally distended then overflow incontinence (parasympathetic supply damaged)
What’s functional incontinence associated with?
Consequence of something not involving LUT
Mobility problems/dementia/DIURETICS: FUROSEMIDE side effect
What drug can be used for urge incontinence / overactive bladders and what’s its MOA?
Oxybutinin = anticholinergic to reduce detrusor activity (parasympathetic)
Blocks M2 and M3 mAChR
(Inhibits: Gq -> PLC -> IP3 -> intracellular rise in Ca2+ and therefore smooth muscle contraction)
What drug can be used for urinary retention (BPH) and its MOA?
Doxasozin = a1 adrenoceptor blocker to facilitate smooth muscle relaxation
(Inhibits: Gq -> IP3 -> Ca2+ increase)
What’s benign prostatic hyperplasia? Symptoms?
Enlarged prostate compresses urethra, common in >50 years
Reduced apoptosis vs increased proliferation
Hesitancy, straining, weak flow of urine, nocturia, feeling that bladder hasn’t emptied properly
