How to measure?
creatinine clearance is overestimate since creatinine is secreted (10%)
CKD EPI equation kidney.org
Creatine clearance noisy (see graph)
Chronic kidney disease
- kidney disease > 3 months
- with or without decreased GFR
- pathological abnl
- abnl blood, urine
- abnl imaging
- GFR < 60 ml/min/1.73 m2
- Identification
- GFR
- albuminuria
- Prevalence = 23 million (1 in 8 people)
- Progession CKD
- intact nephron hypothesis
- remaining nephrons increase their GFR
- glomerular hypertrophy results
- glomerular hypertension results in proteinuria - treat with ACE inhibitors (dilation of efferent arterioles)
- trade off hypothesis
- Stages of CKD
- stage 1 - GFR >90
- stage 2 - GFR 60-89
- stage 3 - GFR 30-59
- stage 4 - GFR 15-29 - all patients should be referred for transplant
- stage 5 - GFR < 15 - need renal replacement therapy
- Risk factors for CKD
- African Americans (3.8 x)
- Zuni Indians (highest rate in world)
- age (GFR declines 1 ml/min/year starting at age 45)
- etc.
- Screening for CKD
- proteinuria
- Complications of CKD
- anemia - decreased EPO production
- keep Hb at 10-11 g/dL
- treat with Fe
- use EPO stimulating agents only if Hb < 10g/dL (increased risk of stroke if ESA used with Hb>11 g/dL
- Secondary hyperparathyroidism (trade off hypothesis)
- hypocalcemia - decreased Vit. D -stimulate PTH
- treat with activated Vit. D.
- inhibiter of CaSR, decreases PTH secretion ($5000 per month)
- hyperphosphatemia
- malnutrition
- low albumin in plasma = increased mortality risk
- goal albumin > 3.5-4 g/dL
- hyperkalemia
- goal keep K < 5 mEq/L
- acidosis
- goal keep HCO3- > 20-22mEq/dL
- uremia
- abnl water/electrolytes
- cardiovascular
- GI
- blood
- neuro
- endocrine
- Treatment
- Renal replacement therapy -
- hemodialysis
- av fistula allows high flows in vein for dialysis
- countercurrent exchange - diffusion & ultrafiltration (hydrostatic pressure removes excess fluid - also lose some wanted solutes)
- peritoneal dialysis
- glucose containing solution (hyperosmotic) infused into peritoneal cavity
- osmotic attraction for plasma to lose water and solutes
- fluid then drained
- transplantation - lowers mortality
- deceased donor
- 6 year waiting list in NM (longest for type O)
- greatest success with HLA identical sibling donor (Human Leukocyte Antigen)
- living related & unrelated
- tested for eligibility
- recipient treated with immune suppressants
