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35 Cards in this Set
- Front
- Back
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Renal replacement options:
Breakdown-- Transplants vs. dialysis |
2% transplant
98% dialysis no treatment--hospice |
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what % of dialysis patients recieve peritoneal vs. hemodialysis?
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7% peritoneal dialysis
93% hemodialysis >>>99% in-center hemodialysis |
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Transplantation
Absolute Contraindications: |
1. advanced forms of major extrarenal comorbidities (stroke, coronary artery disease & cancer)
2. severe psychiatric illness 3. persistent substance abuse |
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Transplantation
Relative Contraindications: |
1. physiological age
2. aortoiliac or iliofemoral occlusive disease 3. morbic obesity 4. treated malignancy or history of substance abuse |
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Indications for Chronic Dialysis
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1. Scr > 12 or BUN > 100
2. Intractable nausea/vomiting 3. Uremic encephalopathy or neuropathy 4. severe hyperkalemia 5. uncontrolled fluid overload/CHF 6. uremic pericarditis 7. pruritus 8. myoclonus(jerk and seizure) AEIOU= acute dialysis |
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Hemodialysis Components:
LIST |
1. Access
2. Dialysate soln. 3. dialysis membrane(dialyzer) 4. dialysis machine 5. dialysis prescription |
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Hemodialysis Components:
Dialysis Access |
1. Arteriovenous (AV) fistula:
-Anastamosis(connection) of an artery & vein in arm -Allows vein to withstand high pressures and freq. sticks -Req. 1-2 mos. to mature 2. Arteriovenous (AV) grafts -Artificial connection made b/w an artery & vein in arm using synthetic tubing -Takes 2-3 wks. to mature 3. Central venous catheter -Placed in the femoral, subclavian, or internal jugular vein -Can be used immediately -More complications(infection, short term only) |
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Hemodialysis Components:
Dialysate Solution |
Purified water (public supply-remove contaminants, Al, Fluoride, bacteria, endotoxin)
Electrolytes (normal Na, Cl, glucose, low K and Ca, high bicarb) ~200 Ltrs dialysate per treatment session |
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Hemodialysis Components:
Dialysis Membrane/Dialyzer |
-Interface b/w blood and dialysate
-hundreds on market -differ according to membrane composition, pore size, SA, & biocompatibility -conventional vs. high efficiency vs. high flux -cost ~ $20-25 each |
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Hemodialysis Components:
Dialysis Machine |
-Monitors patient(BP, dry wt.)
-controls blood and flow rates -controls ultrafiltration (fluid loss) *dry wt. = post dialysis target wt. |
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Hemodialysis Components:
Dialysis Prescription |
-blood flow rates (200-500 ml/min)
-dialysis flow rate (500-800 ml/min) -time on dialysis -ultrafiltration rate (goal fluid/wt. loss) -type of dialyzer (filter type) |
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How Hemodialysis Works:
Fluid Removal |
Ultrafiltration-->
movement of fluid accross the dialyzer membrane due to hydrostatic pressure(osmotic) difference (transmembrane pressure gradient) * (-) pressure on dialysate side, (+) pressure on blood side->pull fluid to balance pressure |
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How Hemodialysis Works:
Waste/Solute Removal |
Diffusion-->
concentration gradient (main waste removal) Convection--> dissolved solutes are "dragged" across the membrane with fluid (via ultrafiltration) |
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Hemodialysis Complications:
Intradialytic |
1. hypotension (20-30%)
2. N/V (5-15%) 3. muscle cramps (5-20%) |
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Hemodialysis Complications:
Other |
1. access site infection/bacteremia(sepsis)
#1 cause death in dialysis pts. 2. amyloidosis (joint & muscle main) 3. AV fistula/graft/catheter thrombosis |
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Hemodialysis Advantages
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1. tecnique failure low
2. closer monitoring 3. higher solute clearance 4. better able to measure adequacy of dialysis |
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Hemodialysis Disadvantages
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1. 3-4 hrs/day x 3 days/wk
2. dialysis complications 3. access complications 4. decline in residual renal function(kills off last few nephrons) 5. encourages dependency |
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Types of Peritoneal Dialysis
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1. Automated peritoneal Dialysis(APD)
58% 2. Continuous ambulatory dialysis (CAPD) 42% |
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Peritoneal Dialysis Components:
LIST |
1. access
2. dialysate 3. blood supply = blood vessels supplying and draining the abdominal viscera, musculature and mesentery (*main diff. from hemodialysis) 4. Dialyzer membrane=peritoneal membrane 5. prescription ***Internal dialysis |
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Perintoneal Dialysis:
Access |
Access= catheter inserted surgically through the abdominal wall
Subcutaneous and Deep "cuffs" allow skin and tissues to grow into access and make a seal |
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Perintoneal Dialysis Components:
Dialysate |
-Soln. contains varying conc. of dextrose (1.5-4.25%) or icodextrin 7.5% (osmotic agent)
-electrolyte conc. are similar to normal serum (Na, Cl, Mg), low Ca, no K, lactate instead of bicarb -1-3 Ltr. bags |
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Perintoneal Dialysis Components:
Dialysis Prescription |
-CAPD(continuous) vs. APD(automated)
- # exchanges per day - duration of dwells - vol. of dialysate for each exchange - type of dialysate used (ex. dextrose conc.) |
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Perintoneal Dialysis
Removal of Metabolic Wastes/solutes |
solutes/wastes removed by diffusion across a concentration gradient
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Peritoneal Dialysis
Removal of Fluid |
removed by altering the osmotic pressure w/in the dialysate (altering dextrose conc. w/in dialysate)
-->1.5% dextrose will remove ~ 200 ml/exchange -->4.25% dextrose will remove ~ 700 ml/exchange |
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Continuous Ambulatory Peritoneal Dialysis (CAPD)
Procedure |
1. Instill 1-3 Ltr. sterile dialysate into peritoneal cavity through surgically placed catheter(every exchange)
2. soln. dwells w/in peritoneal cavity for specified amt. of time (4-12 hrs) 3. fluid drained and replaced w/ fresh soln. 4. ~3 short exchanges during day and 1 long exchange (8-12 hrs) during night |
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Automated Peritoneal Dialysis (APD)
Procedure |
1. Pt. hooked up at night to automated cycler
2. Multiple short dwells/exchanges during the night (~every 1-2 hrs) Wet version: daytime dwell of 12-14 hrs Dry version: no daytime dwell-dry abdomen |
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Peritoneal Dialysis:
Complications |
1. absorption of glucose -->hypertriglyceridemia & wt. gain/obesity
2. loss of albumin and other proteins-->malnutrition 3. increased insulin req. in pts. w/ diabetes--b/c increase in glucose (insulin can be given in dialysate) 4. exit site infections (catheter removal, local care, oral antibiotics)--much more risk than w/ hemodialysis |
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Peritonitis
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***Infection in the peritoneal cavity
-->can limit pt. from being able to continue peritoneal dialysis b/c of scarring Clinical presentation-> pain, fever, cloudy dialysate Diagnosis-> fluid cell count (WBC > 100/mm3 w/ 50% neutrophils and culture) Most common organism-> 40-50% = Gram (+) 25-35% = Gram (-) 10-15% = mixed 5-20% = fungi |
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Peritonitis Treatment
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1. mostly managed outpatient
2. empiric intraperitoneal antibiotics(put into dialysis bag) 3. once culture & sensitivity results ->specific peritoneal antibiotics 4. may need to remove catheter 5. may need to give IV antibiotics |
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Peritoneal Dialysis Advantages
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1. < hemodynamic instability(no dramatic electrolyte shifts b/c slow process)
2. preservation of residual renal function 3. sense of independence 4. < blood loss (better anemia management) 5. convenient route for drug admin 6. better clearance of larger solutes(no amyloidosis) |
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Peritoneal Dialysis Disadvantages
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1. dialysis complications (hypertriglyceridemia)
2. access complicaitons (infection) 3. technique failure is high 4. pt. burnout 5. difficult to determine adequacy of solute removal ***Not as good as hemodialysis at removing wastes/solutes |
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Peritoneal Dialysis
Absolute Contraindication |
peritoneal adhesions from previous surgery(b/c damaged membrane)
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Peritoneal Dialysis
Relative Contraindication |
1. ostomy
2. blindness 3. quadraplegic 4. physical/mental handicap 5. inflammatory bowel disease 6. morbid obesity(not efficient enough) |
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Continuous Renal Replacement Therapies (CRRT) for Acute Renal Failure
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SCUF-slow continuous ultrafiltration
MOST COMMON: CVVH/CAVH-->continuous veno-venous/aterio-venous hemofiltration CVVHD/CAVHD-->continuous veno-venous/aterio-venous hemodialysis(high flux) CVVHDF/CAVHDF-->continuous veno-venous/aterio-venous hemodiafiltration |
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CRRT to manage ARF
Key Points |
1. untilize ultrafiltration +/- diffusion
2. may result in significant drug removal --larger molecules removed than HD --continuous removal 3. Arterial based uses pt's BP as driving force 4. venous based uses pump to move blood through circuit(used more than arterial CRRT) 5. replacement fluid w/ electrolytes needed w/ ultrafiltration |
