Kidney Disease PDF

MNT FOR RENAL DISORDERS Allison Charny, MS, RDN, CDCES, CDN From Krause’s Food & the Nutrition Care Process Overview Nephrolithiasis Acute Kidney Injury Chronic Kidney Disease End Stage Renal Disease Function and Physiology of the Kidney Two kidneys Either side of the spine, below...

MNT FOR RENAL DISORDERS Allison Charny, MS, RDN, CDCES, CDN From Krause’s Food & the Nutrition Care Process Overview Nephrolithiasis Acute Kidney Injury Chronic Kidney Disease End Stage Renal Disease Function and Physiology of the Kidney Two kidneys Either side of the spine, below the rib cage Size of a fist, kidney bean shape Each weighs ~ 1/4 pound ~ 140 miles of tubes and filters One kidney can do the job of 2 as needed Functions Eliminates waste by filtering blood Regulates RBC production and blood formation Regulates BP Controls the body’s chemical and fluid balance Elimination of Waste Nephron Urine Production Blood → Kidney → Nephrons (1 million / kidney)  Glomerulus cluster of blood vessels filters blood passive transport ultrafiltrate formed 180 L/day fluid as ultrafiltrate  Tubules reabsorption of components of ultrafiltrate active transport  Collecting Tubule ~1.5 L / day urine  Renal Pelvis → Ureter → Bladder Elimination of Waste Renal function - kidney’s ability to eliminate N waste N waste - end product of protein metabolism - is excreted in the urine urea, uric acid, creatinine, ammonia Average urine production ~ 1.5 L / day Minimum of 500 ml of urine volume is needed to eliminate daily solute load of waste from normal metabolism < 500 ml / day volume of urine = oliguria Regulation of RBC Production Kidney produces hormone erythropoietin Erythropoietin regulates RBC formation and release in the marrow Deficiency of erythropoietin occurs with kidney disease Anemia results Regulation of Blood Pressure Renin - Angiotensin Mechanism Renin produced in kidney Control of Fluid and Chemical Balance Sodium Most important element in determining blood volume (renin - angiotensin system) If only a 1% change in blood volume, then changes are seen in the urine and blood composition of K, bicarbonate, and water Calcium / Phosphorous homeostasis Kidney produces active form of vitamin D, needed to absorb Ca in the gut and for bone Kidney eliminates Ca and P Regulation of Na, K, P, Ca, Mg, H2O and H2 ions Acute Kidney Injury (AKI) Sudden  GFR  ability of the kidney to excrete metabolic waste Either oliguric or normal urine flow Fluid and electrolyte imbalances Lasts for few days or weeks RIFLE Risk, Injury, Failure, Loss, ESRD Indicates potential of recovery or progression to CRF – helps RD decide protein goals based on kidney function http://cjasn.asnjournals.org/content/1/6/1314.full AKI Causes Prerenal Inadequate perfusion - impaired blood flow to the kidneys i.e. hypovolemia, dehydration, heart failure Intrinsic Drug toxicity Inadequate perfusion - impaired blood flow to the kidneys i.e. hypovolemia, dehydration, heart failure Post renal Disease causing obstruction – i.e. bladder, prostate cancer, stones BUN:CR Ratio varies based on underlying cause of AKI AKI Phases Oliguric < 500 ml urine output / day electrolyte imbalance  BUN; creat;  K; P;  Mg Na; CO2; H/H; Ca Diuretic  Urine output ~200% K  or  Na Convalescent Lab values stable Medical Management Based on severity of AKI, medical management may include dialysis: RRT HD PD Significant AKI in ICU may require continuous rather than periodic dialysis treatment CRRT CVVHemofiltration Diffusion Convection CVVHDialysis SCUF - slow continuous ultrafiltration AKI MNT Correct uremia, metabolic acidosis, fluid and electrolyte imbalances Provide adequate kcal and protein due to metabolic stress (infection or tissue damage) Early phase  appetite, N/V, diarrhea Dialysis TPN AKI Protein 0.5–0.8 g/kg for non-dialysis and 1–2 g/kg for dialysis; in CRRT, can be1.5-2.5 g/kg Energy 25–40 kcal/kg of upper end ideal body weight AKI Potassium (K+) 30–50 mEq/day in oliguric phase (depending on urinary output, dialysis, and serum K+ level); replace losses in diuretic phase Sodium 20–40 mEq/day in oliguric phase (depending on urinary output, edema, dialysis, and serum Na+ level); replace losses in diuretic phase Fluid Replace output from the previous day (vomitus, diarrhea, urine) plus 500 mL Chronic Kidney Disease (CKD) Decreased GFR, loss of nephrons, progressive loss of function due to Diabetes, HTN, glomerulonephritis CKD Estimate the GFR from creatinine, age, sex, race: http://egfrcalc.renal.org/ Progression of CKD slowed by  protein in the diet Recommendations for dietary protein GFR > 55 ml/min.8g/ kg (IBW)/day; 60% HBV GFR 25-55 ml/min.6g/kg (IBW)/day; 60% HBV GFR < 25 ml/min.6g/kg is maintained if intake poor:.75g/kg and 50% HBV Normal GFR ~ 120ml/ml Pyelonephritis Pyelonephritis urinary tract infection (UTI) MNT cranberry and blueberry juice  bacteria in urine inhibits the adherence of E-coli in urinary tract Nephritic Syndrome Main cause strep infection Damages the barrier to the RBC Hematuria, HTN, mild loss of renal function Treat underlying disease May lead to chronic nephrotic syndrome or ESRD Nephrotic Syndrome Main cause DM, SLE (Lupus), amyloidosis Protein barrier in the glomerulus altered Urinary protein loss, mainly albumin Treat underlying disease Leads to proteinuria, hypoalbuminemia, edema, hyperlipidemia End Stage Renal Disease (ESRD) When 1/2 to 2/3 of function lost, kidney failure  BUN & Creatinine BUN > 100mg/dl (norm: 8-23) Creatinine: 10-12 mg/dl (norm:.6-1.2) Symptoms of uremia  Muscle weakness, muscle cramps, itching, neurological impairment Dialysis or kidney transplant is needed Dialysis Hemodialysis (HD) Most common Fistula connection of artery and vein Permanent access Blood crosses semi-permeable membrane of the “artificial kidney” and removes waste. Dialysate ~ to normal plasma 3-5 hours/treatment, 3x/week https://www.kidney.org/atoz/content/hemodialysis Hemodialysis https://www.niddk.nih.gov/health- information/kidney-disease/kidney- failure/hemodialysis Hemodialysis Dialysis Peritoneal Dialysis (PD) Uses peritoneum as the semipermeable membrane  dextrose solution inserted via catheter into peritoneum Diffusion carries waste through the peritoneal membrane into peritoneum This solution is then withdrawn and discarded https://www.kidney.org/atoz/content/peritoneal Peritoneal Dialysis Peritoneal Dialysis Dialysis Continuous Ambulatory Peritoneal Dialysis (CAPD) Dialysate in peritoneum is exchanged manually 4-5 x daily. Problems Peritonitis, wt gain from dialysate, additional fluid and sodium replacement Videos: Overview of dialysis: https://www.youtube.com/watch?v=IQKQ4eoKfTg Guide to Blood Values in ESRD Normal blood values for people on dialysis compared to normal values see Table 34-10. General MNT for Pre-ESRD, Hemodialysis, Peritoneal Dialysis Pre-ESRD Hemodialysis CAPD or CCPD (impaired renal function) *Protein (g/kg IBW) 0.6-.1 1.2 1.2-1.5 Energy (kcal/kg IBW) 30-35 35 30-35 Phosphorus.8-1.2.8-1.2.8-1.2 (g/day) Sodium (g/d) 1.5-2 1.5-2 1.5-4 Potassium (g/day) Unrestricted 2-3 3-4 *Fluid (ml/d) Unrestricted 750-1000 + 1000 + urine output urine output min. Goals of Medical Nutrition Therapy for End-Stage Renal Disease Prevent deficiency and maintain good nutritional status Control edema and electrolyte imbalance Prevent or retard renal osteodystrophy Palatable attractive diet that fits lifestyle Fluid and Sodium Balance in End-Stage Renal Disease Measure blood pressure, edema, fluid weight gain, serum sodium, and dietary intake Modify sodium and fluid intake accordingly Most dialysis patients need to restrict sodium Allow weight gain of 4 to 5 lb between dialyses Potassium in End-Stage Renal Disease Usually requires restriction Monitor laboratory values, content of dialysate, and laboratory values Potassium in foods considered Potassium in salt substitutes considered Protein and Energy in End-Stage Renal Disease Dialysis drains body protein Require higher protein intakes and >50% high BV Energy intake must be adequate to spare protein  Kinetic Modeling Evaluates the efficacy of dialysis Measures removal of urea from blood over a given period of time KT/V Urea reduction ratio (URR) Calcium, Phosphorus, and Vitamin D in End-Stage Renal Disease Metabolic bone disease or renal osteodystrophy Osteomalacia (bone demineralization) Osteitis fibrosa cystica (hyperparathyroidism) Metastatic calcification of joints and soft tissues Low turnover bone disease restrict dietary phosphate to 40 mg oxalate in 24 hour urine Causes Fat malabsorption  absorption of oxalate in the gut presence of oxalate degrading microbes in the gut  Vit C intake with CKD rare metabolic over-production of oxalate MNT   fluids  high oxalate foods: nuts, beets, rhubarb, chocolate, spinach, tea, wheat bran, strawberries Probiotic oxalobacter formigens  calcium with meals Nephrolithiasis: Uric Acid Stones Associated with diabetes, hypertension and obesity; acid urine; gout Causes Dehydration Low urine pH from  intake of acid producing foods (animal protein and excess CHO)  intake of alkali producing foods (fruits and vegetables) MNT   fluids  high purine foods: organ meats, anchovies, herring, sardines, meat-based sauces  protein to the DRI raise urine pH high alkaline citrate (potassium citrate)