Gerontological considerations
- Sclerosis of glomerulus and renal vasculature
- Decreased blood flow
- Decreased GFR
- Altered tubal function and acid-base balance
- Incomplete emptying of bladder, urinary stasis, decreased nerve interventions
- Decreased drug clearance
Functions of the kidneys
- Urine formation
- Excretion of wastes
- Regulation of lytes
- Control of water balance
- Regulation of acid-base balance
- Control of BP
- Renal clearance
- Regulation of RBC production
- Synthesis of vit D to active form
- Secretion of prostaglandins
Renal function tests
- Renal concentration: specific gravity (1.010-1.025), urine osmolality (250-900 mOsm/kg/24 hr)
- 24 hr urine: creatinine clearance
- Serum: creatinine (0.6-1.2), BUN (7-18, >60 8-20), BUN to creatinine ratio (10:1)
Diagnostic tests
- UA, urine culture
- Renal function tests
- US
- CT/MRI
- Nuclear scans
- Endoscopic procedures
- Biopsies
- IV urography
- Retrograde pyelography
- Cystography
- Renal angiography
Stages of kidney failure
- I = GFR > 90 —> kidney damage w/normal or increased GFR
- II = GFR 60-89 —> mild decrease GFR
- III = GFR 30-59 —> moderate decrease GFR
- IV = GFR 15-29 —> severe decrease GFR
- V = GFR < 15 —> ESRD
Causes of acute kidney failure
- Hypovolemia
- Hypotension
- Reduce CO, HF
- Obstruction of kidney or lower urinary tract
- Obstruction of renal arteries or veins
Causes of chronic kidney failure
- DM
- HTN
- Chronic glomerulonephritis
- Pyelonephritis or other infections
- Obstruction
- Hereditary lesions
- Vascular D/O
- RX’s, toxic agents
Acute nephritic syndrome
Causes
Post-infectious glomerulonephritis, rapidly progressive glomerulonephritis, membranous glomerulonephritis
Acute nephritic syndrome
S/S
Hematuria, edema, azotemia, proteinuria, HTN
Azotemia
Build up of nitrogenous wastes in urine
Acute nephritic syndrome
Management
- Supportive care, dietary modifications
- Treat if appropriate: ABX, corticosteroids, immunosuppressants
Abnormal lab tests in chronic glomerulonephritis
Urine w/fixed specific gravity, casts, proteinuria, electrolyte imbalances, hypoalbuminemia
S/S of nephrotic syndrome
Hypoalbuminemia, edema
Nephrotic syndrome
Causes
Chronic glomerulonephritis, DM w/intercapillary glomerulonephritis, amyloidosis, SLE, multiple myeloma, renal vein thrombosis
Complications of CKD
Hyperkalemia Pericarditis Pericardial effusion, tamponade HTN Anemia Bone disease, metastatic calcifications
Complications of PD
Peritonitis, leakage, bleeding, infection
Nutrition for CKD
- High calorie, low protein (protein must be of high biological value —> dairy, eggs, meats)
- Fluid allowance is 500-600mL more than previous day’s 24 hr UO
- Restriction of potassium
- Vitamins & supplements due to low protein in diet
