Urinary Tract Obstruction PDF

Urinary Tract Obstruction Urinary tract obstruction is an interference with the flow of urine at any site along the urinary tract Obstruction can be caused by an anatomical change (obstructive uropathy) or functional defect Severity based on: - Location - Completeness - Involvement of ureter...

Urinary Tract Obstruction Urinary tract obstruction is an interference with the flow of urine at any site along the urinary tract Obstruction can be caused by an anatomical change (obstructive uropathy) or functional defect Severity based on: - Location - Completeness - Involvement of ureters and kidneys - Duration - Cause Urinary Tract Obstruction Sites Upper: common causes include stricture, compression of a calyx (calculi, tumor, inflammation or scarring), or ureteral blockage Lower: common causes include storage of urine (overactive bladder) or emptying of urine (urethral stenosis, prostate hypertrophy)... neurogenic or anatomical Upper Urinary Tract Obstruction Hydroureter: kinking and dilation of the ureter Hydronephrosis: enlargement of the renal pelvis and calyces Ureterohydronephrosis: dilation of both the ureter and the renal pelvis & calyces →dilation is an early response to obstruction; increased pressure decreases filtration Response to Relief of Obstruction: diuresis (post-obstructive), restoration of fluid balance and correction of electrolyte imbalance (lose K+ with diuresis) Kidney Stones- Upper Urinary Tract Obstruction Renal calculi or urinary stones are masses of crystals, protein or other substances that form within and may obstruct the urinary tract The stones are usually made from calcium oxalate, calcium phosphate, struvite (magnesium-ammonium-phosphate) or uric acid Risk Factors - Gender (male), age, race (Caucasian), geographical location & seasonal factors - Geographical location & season; what is their influence on fluid intake & dietary patterns? - Decreased fluid intake - Infection (inflamed or scarred tissue provide a site for calculus development) - Obstruction (allows collection of substances that create a stone) - Diet (increased intake of calcium of oxalate-rich food) Kidney Stones- Upper Urinary Tract Obstruction Pathophysiology Supersaturation of one of more salts in the urine Precipitation of salts from liquid to solid (temperature & pH) ○ Acidic urine 90 mL/min) ○ Mild (GFR 60 to 89 mL/min) ○ Moderate (GFR 30 to 59 mL/min) ○ Severe (GFR 15 to 29 mL/min) ○ End stage (GFR