1
Q
Principles of Dialysis
A
Solutes and H20 move across a semipermeable membrane from blood to pending on concentration gradients
2
Q
Osmosis
A
Water moves by concentration gradient
-lesser to higher concentration
3
Q
Diffusion
A
Solvent moves by concentration gradient
4
Q
Ultrafiltration
A
Solution moves by pressure gradient
5
Q
Purpose of dialysis
A
- correct fluid and electrolyte balances
- remove waste products and excess
6
Q
Primary indication for dialysis
A
- based on clinical status
- uremia unable to be managed conservatively
- GFR or creatinine clearance
7
Q
Who needs Dialysis?
A
A: Acid-Base Problems
E: Electrolyte Problems
I: Intoxifications
O: Overload of fluids
U: Uremic symptoms
8
Q
Peritoneal Dialysis (PD)
A
- peritoneum acts as the dialyzing membrane
- works on principles of osmosis, diffusion, and ultrafiltration
- transfer of fluid and solute from the bloodstream, through the peritoneum into the dialysate solution
- peritoneal membrane is large and porous
- peritoneal cavity is rich in capillaries
9
Q
Contraindications for PD
A
- Peritonitis
- Recent abdominal surgery
- Abdominal adhesions
- Other GI problems
10
Q
Access for PD
A
- Siliconized rubber catheter is surgically inserted into the client’s peritoneal cavity
- 3 to 5cm below the umbilicus
- Catheter is tunneled under the skin, through fat and muscle tissue to peritoneum
- Stablized with inflatable Dacron cuffs in the muscle and under the skin
- Fibroblasts and blood vessels grow around the cuff
11
Q
Dialysate Solution
A
- Sterile
- Prescribed by physician
- Contains electrolytes and minerals
- specific osmolarity, glucose concentration, and other medications additives as prescribed
- the higher the glucose concentration, the greater the hypertonicity and the amount of fluid removed during exchange
- K+ may be added if hyperkalemia is not a problem
- Heparin is added to each bag to prevent clotting of the catheter
- Antibiotics may be added to prevent peritonitis
- Insulin may be added for the patient with DM
12
Q
Increasing the glucose concentration of the dialysate solution…..
A
- increases the concentration of active particles that cause osmosis
- increases the rate of ultrafiltration
- increases the amount of fluid removed
13
Q
Interventions before Tx
A
- Monitor VS
- Obtain weight
- Have client void, if possible
- Assess electrolyte and glucose levels
14
Q
Interventions during Tx
A
Monitor:
- VS
- Resp. Distress
- Pain
- discomfort
- signs of pul. edema
- hypo/hypertension
- malaise
- N/V
- Dwell time as prescribed
- Outflow should be continuous stream after clamp is opened
- Color and charity
- I & O accurately
15
Q
Complications of PD
A
- Peritonitis
- Abdominal Pain
- Abdominal outflow
- Leakage at the catheter site
16
Q
Peritonitis
A
- fever
- cloudy outflow
- rebound abdominal tenderness
- abdominal pain
- malaise
- N/V
- obtain a sample of outflow for C&S
- admin antibiotics
**maintain meticulous sterile technique
- prevent catheter insertion site from becoming wet
- follow institutional policy for connecting and disconnecting PD solution bags
17
Q
Abdominal pain
A
- peritoneal irritation during inflow
- warm dialysate before admin
18
Q
Abnormal outflow
A
- bloody outflow: vascular complications
- brown outflow: bowel perforation
- urine: colored outflow: bladder perforation
- cloudy outflow: peritonitis
19
Q
Insufficient outflow
A
- main cause is a full colon
- catheter migration out of the peritoneal area
- maintain drainage bag below client’s abdomen
- kinks in the tubing
- fibrin clots in the tubing
- change client’s position
20
Q
Leakage at the catheter site
A
- clear fluid from the exit site should be reported
- takes 1 to 2 weeks from fibroblasts and blood vessels grow into the catheter cuffs
- smaller amounts of dialysate
21
Q
Types of PD
A
- Continuous ambulatory peritoneal dialysis (CAPD)
2. Automated peritoneal dialysis
22
Q
Continuous ambulatory peritoneal dialysis (CAPD)
A
- 4 dialysis cycles are administered in a 24-hour period
- Includes 8-hour dwell time overnight
-Dialysate (1-2L) instilled and allowed to dwell
as prescribed
- After dwell, bag is placed lower than insertion site
- After fluid drains, bag is changed, new dialysate instilled and process continues
- Between exchanges, catheter is clamped
23
Q
Automated peritoneal dialysis
A
- Requires a peritoneal cycling machine
- Can be done as: Intermittent, Continuous, Nightly
- Exchanges are automatic instead of manual
24
Q
Advantages of PD
A
- can be used immediately after catheter placement
- less complicated
- fewer dietary restrictions
- No rapid fluctuations in ECF and waste removal
25
Why is PD less complicated?
- No vascular access
- Short training time
- Better self management
- Portable: Home, work
26
Disadvantages of PD
- Peritonitis common
- protein loss into dialysate
- hyperglycemia, hyperlipidemia
- contraindicated with prior GI problems
- Need for special training
- Surgery to place catheter
- Less effective removal of solutes and fluid
27
Hemodialysis (HD)
- Process of cleansing the client's blood
- Diffusion of dissolved particles from one fluid compartment into another across a semipermeable membrane
- Client's blood flows through one fluid compartment of a dialysis filter
- Dialysate is in another fluid compartment
28
Functions of HD
- Cleanses the blood of accumulated waste products
- Removes byproducts of protein metabolism: Urea, creatinine, uric acid
- Removes excess body fluids
- Maintains or restores buffer system of the body
- Corrects electrolyte levels
29
Principles of HD
Semipermeable membrane is made of thin, porous cellophane
Pore size of the membrane allows small particles to pass through (urea, creatinine, uric acid, H20)
Proteins, bacteria, some blood cells are too large to pass through
Blood flows into the dialyzer
Movement of substances occurs from the blood to
the dialysate by principles of osmosis, diffusion, ultrafiltration
30
Dialysate Bath
- composed of H20 and electrolytes
- Need not be sterile because bacteria and viruses are too large to pass through, dialysate must meet specific standards, water is treated to ensure a safe water supply
31
Interventions of HD
- Monitor VS before and after
- Monitor lab values before, during, and after
- Assess for HYPERvolemia before
- Assess HYPOvolemia after
- Weigh client before and after
- Assess blood access device before, during, and after
- Monitor for bleeding
- Provide adequate nutrition
***Withhold antihypertensives and other meds that can affect BP until after tx
***Withhold meds that can be removed by dialysis
***water-soluble vitamins, certain antibiotics, digoxin
32
Access for HD
- Subclavian
| - Femoral
33
Subclavian catheter
- catheters usually fill with heparin and capped to maintain patency
- catheter should not be uncapped except for dialysis
- client with femoral vein catheter should not sit up more than 45 degrees or lean forward
34
Femoral
- Assess extremity for circulation, temp, and pulses
- meticulous peri care
- use an IV pump or controller with microdrip tubing if heparin infusion is prescribed
35
External Arteriovenous shunt
- 2 silastic cannulas surgically inserted into an artery and a vein in forearm or leg
- forms an external blood path
- cannulas are connected to form a U
- Blood flows from artery through the shunt into the vein
- tube leading to the membrane compartment of the dialyzer is connected to the arterial cannula
- blood fills the membrane compartment, passes through the dialyzer, is returned back to the client through a tube connected to the venous cannula
- when complete, the cannulas are clamped and reattached reforming the U
36
Advantages of External Arteriovenous Shunt
can be used immediately following insertion
37
Disadvantages of External arteriovenous shunt
- disconnection/dislodgment
- risk of hemorrhage, infection, clotting
- potential for skin erosion at catheter site
38
External Shunt Interventions
- avoid getting shunt wet
- wrap a dressing completely around the shunt
- keep cannula clamps at bedside
- teach client that shunt extremity should not used for: BP, blood draw, IV access, IM injections
- fold back the dressing to expose the shunt tubing and assess for: hemorrhage, infection, clotting, auscultate for bruit, palpate for thrill
39
Internal Arteriovenous Fistula
- permanent access of choice for clients with CRF requiring dialysis
- fistula created surgically by anastomosis of a large artery and a large vein
- flow of arterial blood into the venous system causes vein to become engorged
- maturity takes 4-6 weeks
- engorged vein is punctured with a large pore needle for dialysis
40
Advantages to internal artiovenous fistula
- risk of clotting/bleeding is low
- can be used indefinitely
- decreased incidence of infection
- no external dressing is required
- allows freedom of movement
41
Disadvantages of Internal arteriovenous fistula
- Can't be used immediately so it requires alternate access
- needle insertions through skin are required
- infiltration of the needles can occur and can hematomas
- aneurysm can form in the fistula
- CHF can occur from the increased blood flow in the venous system
- arterial steal syndrome
42
Internal Arteriovenous Graft
- internal graft used for clients who don't have adequate blood vessels for creation of a fistula
- artificial graft made is made of Gore tex or bovine carotid artery
- anastomosis of an artery to a vein using an artifical graft
- graft can be used within 2 weeks of insertion
- complications include clotting, aneurysms, infection
43
to ensure patency of internal arteriovenous graft....
palpate for a thrill and auscultate for a bruit over the fistula or graft
notify MD if absent
44
Complications of HD
-air embolus
45
Clinical manifestations of air embolus
- dyspnea/tachypnea
- chest pain
- hypotension
- decreased O2 sats
- cyanosis
- anxiety
- changes in sensorium
46
Nursing Action for patient who develops air embolism during HD
- stop hemodialysis
- turn the client on the left side
- place the client head down (Trendelenberg's)
- notify the physician
- admin O2
- assess VS and pulse ox
- document the event, actions taken, and client's response
MS2 Exam 1
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