Uronephrology Labs PDF

Uronephrology Labs Jamie Harding PA-C Campbell University PA Program Objectives 1. 2. 3. 4. Review the anatomy and physiology of the kidneys. Discuss the benefits and limitations of the various tests of kidney function. Identify the normal values of blood chemistry tests for kidney disease. Utilize...

Uronephrology Labs Jamie Harding PA-C Campbell University PA Program Objectives 1. 2. 3. 4. Review the anatomy and physiology of the kidneys. Discuss the benefits and limitations of the various tests of kidney function. Identify the normal values of blood chemistry tests for kidney disease. Utilize renal function tests to differentiate between pre-renal, intra-renal, and post-renal causes of decreased kidney function. 5. Discuss the components assessed by and interpretation of the following urine analyses: a. Macroscopic b. Microscopic c. Chemical (urine dip) 6. Discuss the purpose, indications, and interpretation of urine culture and sensitivity. 7. Describe the significance and interpretation of the Glomerular Filtration Rate (GFR) and Creatinine Clearance (CrCl) as related to patient management. 8. Calculate a CrCl using the Cockcroft-Gault equation. 9. Describe the role of commonly obtained urinary electrolytes and the fractional excretion of sodium (FENa) in the diagnostic process. 10. Given a clinical scenario, develop an appropriate diagnostic approach to a patient with a uronephrologic complaint. URINARY TRACT NEPHRON in Renal Pyramid NEPHRON: filtration and collection; Hormones; BP Meds Where Does Urine Go Next? Micturition: Where Does Urine Finish? Basic Metabolic Panel (BMP) Basic Metabolic Panel Electrolytes Kidney fxn Glucose Na+ Cl- Bun Glucose K+ CO2 SCr Approach: 1. Elevated BUN and Cr 2. 3. 4. 5. 6. Look at their baseline Look for nephrotoxic agents Is it pre-renal, renal or post renal? r/o post renal first (think obstruction) Look at BUN:Cr Renal Function Serum Creatinine (SCr) Blood Urea Nitrogen(BUN) A product of muscle mass Normal rage:0.6-1.2mg/dL adults (~1) A product of breakdown of blood Normal range: 8-20 mg/dL Elevation=azotemia Variable based on muscle mass (sex and age) 1. Elevated BUN and Cr 2. Look at their baseline 3. 4. 5. 6. Look for nephrotoxic agents Is it pre-renal, renal or post renal? r/o post renal first (think obstruction) Look at BUN:Cr Baseline labs Find them! Look back in chart Contact previous PCP or hospital If nothing available, ask patient if they have had kidney trouble before 1. Elevated BUN and Cr 2. Look at their baseline 3. Look for nephrotoxic agents 4. Is it pre-renal, renal or post renal? 5. r/o post renal first (think obstruction) 6. Look at BUN:Cr Look for nephrotoxic agents Most common nephrotoxic agents? 1. Elevated BUN and Cr 2. Look at their baseline 3. Look for nephrotoxic agents 4. Is it pre-renal, renal or post renal? 5. r/o post renal first (think obstruction) 6. Look at BUN:Cr Is it pre-renal, renal or post renal? 1. 2. 3. 4. Elevated BUN and Cr Look at their baseline Look for nephrotoxic agents Is it pre-renal, renal or post renal? 5. r/o post renal first 6. Look at BUN:Cr 1. 2. 3. 4. Elevated BUN and Cr Look at their baseline Look for nephrotoxic agents Is it pre-renal, renal or post renal? 5. r/o post renal first think 6. Look at BUN:Cr obstruction Rule out post renal first MC in a male is enlarged prostate- do a RECTAL! Kidney stone? Ask questions: “Are you urinating well?” Renal scan or foley If so, consult Urology not Nephrology 1. 2. 3. 4. 5. 6. Elevated BUN and Cr Look at their baseline Look for nephrotoxic agents Is it pre-renal, renal or post renal? r/o post renal first (think obstruction) Look at BUN:Cr BUN:Cr ratio Normal= 10:1 Will help differentiate pre-renal vs renal issue > 20:1 suggests blood is not getting to the kidneys pre-renal causes Dehydrations* or CHF or blood loss (GI bleed) 20-40 mEq/L = SIADH (commonly drug induced – SSRI’s) Hypernatremia Plus low urine sodium = Diabetes insipidus Falsely elevated with Diuretics Urinary Fractional Excretion of Sodium (FENA) % sodium filtered in glomerulus and excreted in urine 2-3%: acute tubular necrosis (kidney damage) Falsely elevated with diuretic therapy Clincal Pearls Treat the patient, not the urine, except in your extremes…young, old, pregnancy. Appendicitis can mimic UTI – mild pyuria, proteinuria, hematuria.. If results don’t make sense, consider checking another sample at another time (a day or week later) Always culture urine in elderly and babies or pottytraining children that you don’t trust the “clean catch” urine In females with ovaries/uterus… don’t forget pregnancy test Males get urethritis; UTI only common in young, old, uncircumcised; usually caused by Gonn/ chlamydia, trich Don’t forget your urine Gonn/chlamydia: straight catch/“dirty urine” Cath urines on those who can’t do a clean catch: babies, elderly, unresponsive patient Sources https://medcomic.com/medcomic/urinary-casts/ Basic Skills in Interpreting Laboratory Data https://www.youtube.com/watch?v=icgTvRLjw0o https://youtu.be/XEa6Z6nK-9E