Renal Disease Normal Anatomy andPhysiology

Renal: Normal Anatomy 1. Renal artery and vein: 25% of blood volume passes through the kidney / minute 2. Cortex / Papillae / Pelvis / Ureter / Bladder / Urethra

Kidney : Cortex Papilla Pelvis Ureter

Renal: Normal Anatomy 3. Nephron: high pressure glomerular filtration of H 2 O ions, drugs and wastes (urea) 4. Tubular reabsorption of ions / H 2 O, & concentration of urine

Renal: Normal Anatomy 5. Juxtaglomerular apparatus renin / angiotensin system

Nephron : PCT DCT Glomerulus Renal artery Renal vein Loop of Henle Collecting duct JGA

Renal: Normal physiology 1. Control of fluid volume: H Control of electrolytes: Na / K 3. Control of blood pressure renin / angiotensin / aldosterone

Renal: Normal physiology Renin / Angiotensin / Aldosterone 1.Renin secreted by JGA in response to BP or chronic Na depletion 2.Renin catalyses the production of angiotensin I (a decapeptide) from a circulating protein 3. Angiotensin converting enzyme (ACE) in the lungs cleaves off 2 more amino acids to form Angiotensin II (an octapeptide)

Renal: Normal physiology Renin / Angiotensin / Aldosterone 4.Angiotensin II : is a potent vasoconstrictor and it stimulates the release of aldosterone by the adrenal cortex 5.Aldosterone acts on the collecting tubule to increase the reabsorption of Na (and, therefore H 2 O)

Renal: Normal physiology 4. Control of acid / base balance pH 5. Filtration of the blood: elimination of metabolic wastes 6. Drug metabolism

Renal: Normal physiology 7. Control of Ca / PO 4 activation of vitamin D 8. Red blood cell regulation erythropoietin

Renal failure: Definition ESRD (end stage renal disease) Loss of 50 to 75% of nephrons This implies a huge amount of reserve within the system Will have 2 in 2000 patient practice

Renal failure: Causes 1. Diabetes mellitus (34%) micro and macrovascular disease 2. Hypertension (25%) 3. Chronic glomerulonephritis (16%) 4. Others (polycystic kidney disease, SLE, neoplasms, AIDs, etc)

Renal failure: Assessment 1. Urinalysis: protein or blood 2. Creatinine: increased 3. BUN: increased 4. K increased / Na decreased

Renal failure: Assessment 5. CBC: anemia / thrombocytopenia 6. INR / PTT: increased 7. Creatinine clearance: decreased 8. GFR: decreased

Renal failure: Assessment GFR (glomerular filtration rate): (based on serum creatinine) Normal= ml/min

Renal failure: Assessment: Renal failure: Assessment: GFR Normal: ml/min Renal Insufficiency: Moderate renal failure: Severe renal failure: < 10

Renal failure: Stages 1. Diminished renal reserve: mild increase in Creatinine and 10 to 20% decline in GFR 2. Renal Insufficiency: increase in blood urea nitrogen (BUN) and 20 to 50% decline in GFR

Renal failure: Stages 3.Renal failure: Uremia (> 50% decline in GFR) with loss of excretory endocrine and metabolic function

Renal failure: Pathophysiology 1. Irreversible loss of nephrons 2. Kidneys are able to compensate until 50 to 75% of nephrons are lost 3. Initial polyuria followed by uremia

Renal failure: Pathophysiology 4.Uremia is characterized by: a. Fluid overload … hypertension b. Congestive heart failure c. Pulmonary edema d. Urea buildup (azotemia: BUN) e. Metabolic acidosis ( pH) f. Hyponatremia / hyperkalemia

Renal failure: Pathophysiology 4.Uremia is characterized by: g. Anemia h. WBC dysfunction: immunity i. Platelet & factor coagulopathy j. Renal osteodystrophy: vit D & secondary hyperparathyroidism

Renal failure: Management 1. Conservative care: fluid, K, Na protein and phosphate 2. Recombinant human erythropoietin 3. Treat (optimize) concommitant disease: diabetes, hypertension CHF, infection, etc

Renal failure: Management 4. Avoid nephrotoxic drugs 5. Peritoneal dialysis (10%): hypertonic solution indwelling catheter frequent exchanges

Renal failure: Management 6. Hemodialysis (90%) every 2 to 3 days 3 to 4 hours / session surgical fistula* heparin (6 hour ½ life) risk of Hep B / C and HIV 1 year survival = 78% 5 year survival = 28%

Renal failure: Management 7. Kidney transplant immunosuppression gingival hyperplasia (cyclosporin and CCBs) chronic steroid use 1 year survival = 87% 5 year survival = 76%

Renal failure: Dental concerns 1.Monitor blood pressure … avoid fistula arm 2. Assess for anemia 3. Increased risk of bleeding (heparin effect and thrombocytopenia) 4. Increased risk of infection

Renal failure: Dental concerns 5. Drugs: avoid NSAIDs and acetaminophen in high doses reduce dose of: tetracycline, metronidazole acyclovir penicillins &cephalosporins

Renal failure: Dental concerns 6. Oral complications: xerostomia candidiasis gingival bleeding / petechiae osteodystrophy 7. ??? Prophy Abs for fistula ???

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