Flashcards in CKD Deck (60)
How common is kidney disease in the US? ESRD?
- 9th leading cause of death in the US
- 1 out of 9 adults, less than 2% progress to ESRD, most pts die of CV event before they progress to ESRD
- pts remain asx until their disease has sig progressed
What are over 70% of cases of late stage CKD due to? Less common causes?
- diabetes and HTN
- 12% due to:
glomerulonephritis, cystic disease, and other urological diseases (BPH)
- 15% of pts have other or unknown causes
Definition of CKD?
- GFR of less than 60 ml/min for greater than or equal to 3 months with or w/o kidney damage
kidney damage for greater or equal to 3 months with or w/o decreased GFR
Progression of CKD?
- rarely reversible and leads to progressive decline in renal fxn
- reduction in renal mass leads to hypertrophy of remaining nephrons (kidneys working harder, nephrons trying to compensate: get worn out) - leads to progressive glomerular sclerosis and interstitial fibrosis
RFs for CKD?
- older age
- family hx of CKD
- pt population (Native americans, african americans, alaskan natives, asians)
- autoimmune disease: SLE
- drug toxicity
- systemic infection (shock) - decreased perfusion to the kidneys
- urinary obstruction: stones
Pathophys of CKD?
- 1 kidney = 1 mill nephrons
- with destruction of nephrons, this causes hyperfiltration and compensatory hypertrophy
- blood urea and Cr start to show measurable increase only after GFR has dropped by 50%
- plasma Cr will approx double with 50% reduction in GFR
initial assessment of a pt with suspected kidney disease?
- confirm primary renal dx
- establish chronicity
- ID reversible factors
- detect co-morbid factors
- est a baseline database
Stages of CKD?
- normal: 120-130
- stage 1: kidney damage with normal or increased GFR (greater than 90)
- stage 2: mild reduction in GFR (60-89 ml/min)
- stage 3: mod reduction in GFR (30-59)
- stage 4: severe reduction in GFR (15-29) - sxs
- stage 5: kidney failure (GFR less than 15 ml/min or dialysis)
* stage 1-3 CKd freq asx
clinical manifestations appear in stage 4-5 (indication for kidney transplantation)
Measurement of renal fxn?
- serum creatinine alone isn't an accurate measure of GFR
- creatinine is secreted by renal tubules, and as renal fxn worsens the amt secreted increases
- normal ranges for serum creatinine are misleading b/c they don't account for age, sex, race or wt of pt
Cockcroft Gault formula?
- adjust creatinine for age, wt and gender
- Male: (140-age)x IBW kg)/(serum Crx72)
- in females - top equation x 0.85
What 2 tests should be used together to improve prognostic accuracy?
- GFR and albuminuria
- microalbuminuria: key parameter for measuring nephron injury and repair, early sign of kidney disease
AER staging of CKD?
- A1: less than 30 (normal-mild increase)
- A2: 30-300 (mod increased)
- A3: greater than 300, severly increased
What is azotemia? types?
- condition characterized by high levels of nitrogen containing compounds in the blood
prerenal azotemia (hypoperfusion)
primary renal azotemia (glomerulonephritis)
postrenal azotemia: blockage - stones, BPH, cancer
- azotemia can lead to uremia if left untx
What is uremia?
- condition resulting from advanced stages of kidney failure in which urea and other nitrogen containing wastes are found in the blood
- sxs may not occur until 90% of nephrons are destroyed
- more commonly develops in later stages of CKD
Sxs of uremia?
- general: fatigue, weakness, breath (fishy odor)
- skin: pruritus, easy bruising
- ENT: metatallic taste in mouth, epistaxis
- pulmonary: dyspnea, pulmonary edema
- CV: dyspnea on exertion, retrosternal pain on inspiration (pericarditis)
- GI: anorexia, N/V, hiccups
- GU/GYN: ED, amenorrhea
- NM: restless legs, numbness, cramps
- neuro: irritability, inability to concentrate
Signs of uremia?
- general: sallow appearing, chronically ill
- skin: pallor, ecchymosis, excoriations, edema, yellow
- ENT: urinious breath
- eye: pale conjunctiva
- pulm: rales, pleural effusion
- CV: HTN, cardiomegaly, friction rub, displaced PMI
- neuro: stupor, asterixis (hand flap), myoclonus, periph neuropathy
What will labs look like in uremia?
- elevated BUN/creatinine
- CBC: anemia (can stim EPO)
- CMP: hyperphosphatemia, hypocalcemia, hyperkalemia
- serum albumin levels
- lipid profile: risk for CVD
- urinalysis: broad waxy cast cells
- evidence of renal bone disease can be evidenced on:
intact PTH levels
Imaging for uremia?
- renal U/S: small echogenic kidneys bilaterally
- CT: tumor?
- MRI/MRA: use for pt that can't have contrast
- retrograde pyelogram: can't find cause, maybe an obstruction? put stents in
When is a renal bx indicated? complications?
- indicated: when renal impairment is present and dx is unclear after extensive work up
- complication: bleeding
Complications of uremia/kidney disease?
- hyperkalemia: esp when GFR drops below 10 ml/min, kidneys have decreased ability to secrete K+
can be seen sooner in K+ rich diet
can get ECF shift of K+ with acidemia and decreased insulin
- metabolic acidosis:
damaged kidneys unable to excrete the 1 mEq/kd/d of acid generated by metabolism of dietary proteins
this limits prod of ammonia and limits buffering of H+ in urine
- excess H+ ions buffered by large calcium carb and calcium phosphate stores in bone so this contributes to renal osteodystrophy of CKD
Cardiovascular complications of CKD?
- pericarditis: can be comp by tamponade
- CHF and pulmonary edema
- heart disease: LVH, ischemic heart disease (alot of these pts have arteriosclerosis, at high risk for MI)
Hematologic complications of CKD?
- anemia: normocytic, normochromic
- due to decreased epo production
- Iron def present as well
- coagulopathy: due to platelet dysfxn, platelet counts are mildly decreased but hsow abnormal adhesiveness and aggregation - leed to thrombi and abnorm bleeding
- uremic encephalopathy
- peripheral neuropathy
- sub-arachnoid hemorrhage
Compllications of mineral metabolism?
- disorders of calcium, phosphorus and bone are referred to as renal osteodystrophy: hyperphosp leads to hypocalcemia - PTH stim and this leads to osteitis fibrosa cystica, have higher level of bone turnover
Causes of renal osteodystrophy?
- ability to excrete phosphate is lost
- decreased prod of 1,25 dihydroxyvitamin D leads to decrease intestinal absorption of Ca
- hypocalcemia triggers PTH prod and release
- secondary hyperparathyroidism leads to Ca mobilization from bone and increase renal phosphate excretion to maintain electrolyte homeostasis
- there is a decreased conversion of 25-hyroxycholecalciferal to 1,25 dihydroxy form:
gut absorption of Ca is diminished and aluminum deposition in bone
- will cause bony pain and proximal muscle weakness
Skin disorders - complications from CKD?
- yellow-brown color
- fingernails become thin and brittle
- uremic frost - dry on skin after sweating
Effective CKD management?
- approp screen and dx early CKD
- be aware of CKD complications and comorbidities:
anemia, bone and mineral abnormalities, CV and renal risk, diabetes
- consult a nephrologist in a timely manner
- delay or halt progression by:
tx underlying condition
aggressive BP control: ACEI or ARB
aggressive glycemic control
tx hypocalcemia: calcium supplements
volme overload: loop diuretics
metabolic acidosis: oral alkali supplements
Recommendations for HTN control?
- HTN w/o CRF: less than 130/85
- HTN with CRF and proteinuria - less than 1 g/day
less than 130/80
- HTN with CRF and proteinuria: greater than 1 gram/day less than 125/75