Dialysis Primer Flashcards
What is dialysis?
• Method of filtration w/movement of blood across a semipermeable to remove undesired artifacts
What is dialysis used for?
- Correct fluid/electrolyte imbalances
- Remove waste products in renal failure
- Treat drug overdoses
What are the two types of dialysis?
- Peritoneal dialysis (PD)
* Hemodialysis (HD)
When is dialysis generally initiated?
• When GFR (or creatinine clearance) = <15mL/min
Dialysis uses diffusion and osmosis for filtration.
Diffusion is the movement of fluid from an area of _____ to an area of _____ concentration of solutes.
• greater, lesser
Dialysis uses diffusion and osmosis for filtration.
Osmosis is the movement of fluid from an area of _____ to an area of _____ concentration of solutes.
• lesser, greater
What are some conditions that call for immediate dialysis?
- Uremic complications
- Neuropathies
- Uncontrolled hyperkalemia
- Pericarditis
- Accelerated HTN
What are the components of dialysis?
- Blood
- Semi-permeable membrane
- Dialysate
What is the purpose of dialysate?
• To control filtration gradients of osmosis
The patient preparation for dialysis consists of…
- Emptying the bladder and bowel
- Weighing the patient
- Obtaining a signed consent form.
What is used more often, peritoneal dialysis or hemodialysis?
• Hemodialysis, PD is only used in apprx 12% of pts
What is the basic concept of peritoneal dialysis?
- A dialysis catheter is surgically placed through the abdomen into the peritoneal cavity
- A dialysis solution bag is hung higher than insertion point to drain into peritoneal cavity
- Dialysate draws impurities into the peritoneal cavity
- A drain bag is hung below the insertion point to remove fluids
What is the care for a newly placed PD catheter?
- Site clean to heal (This can be w/ or w/out a dressing pending particulars of the individual)
- Pt is taught to observe for signs of infection
- Site should not be submerged in bathwater
- Once healed, the pt may shower and pat dry
With peritoneal dialysis, what serves as the semi-permeable membrane?
• The peritoneum (lining of the peritoneal cavity)
What is the active component in dialysate that helps control rates of osmosis?
• Glucose
What are the basics to keep in mind re: dialysate for peritoneal dialysis?
- Available in 1 or 2 L plastic bags w/ glucose concentrations of 1.5, 2.5 and 4.25% (3L can be given pending size of pt)
- Electrolyte compositions is similar to plasma
- Solution is warmed to body temperature
What are the 3 phases of the PD cycle?
- Infill
- Dwell
- Drain
Describe the infill phase of PD.
- Prescribed amount of solution infused through established catheter over about 10 minutes
- After solution infused, inflow clamp closed to prevent air from entering tubing
Describe the dwell phase of PD.
- Diffusion and osmosis occur between patient’s blood and peritoneal cavity.
- Duration of time varies, depending on the method.
- 20 – 30 minutes to 8 hours or more
Describe the drain phase of PD.
- Peritoneal fluids are drained over 15 to 30 minutes
* May be facilitated by gently massaging abdomen or changing position
One cycle = one ______.
• Exchange
For manual PD, a period of about __ to __ minutes, minimum, is required to complete an exchange.
• 30 to 50
What is automated peritoneal dialysis?
• An automated mechanical Cycler delivers the dialysate, times and controls fill, dwell, and drain
APD is the most popular form of PD, as it allows patients to accomplish dialysis while they sleep. The machine cycles four or more exchanges per night with __ to __ hours per exchange.
• 1 to 2
What are some complications that may occur with PD?
- Exit site infection
- Lower back problems
- Peritonitis
- Hernias
- Bleeding
- Pulmonary complications
- Protein loss
Because of increased intraabdominal pressure secondary to dialysate infusion, hernias can develop in predisposed individuals such as _____ women and _____ men.
• Multiparous, older
What are some Pro’s of PD over HD?
- Short training program (3 to 7 day training program)
- Independence
- Ease of traveling
- Fewer dietary restrictions
- Greater mobility than with HD
Mortality rates are about equal between in-center hemodialysis patients and peritoneal dialysis patients for the first few years. However, after about 2 years, mortality rates for patients receiving _____ dialysis are higher, especially for the elderly with diabetes and patients with a prior history of cardiovascular disease.
• Peritoneal
How is circulatory access gained for hemodialysis?
• Via an Arteriovenous Fistula (AVF)- an anastomosis between an artery and a vein (usually cephalic)
For acute (temporary) hemodialysis when an AVF is not available, what type of catheter may be used and where would it be placed?
• Double lumen, Y hub catheter in the right jugular
What is the basic procedural flow for hemodialysis?
- Two needles placed in fistula or graft
- Needle closer to fistula or red catheter lumen pulls blood from patient and sends to dialyzer.
- Blood is returned from dialyzer to patient through second needle or blue catheter.
_____ may be infused as a bolus predialysis or through a _____ pump continuously to prevent clotting.
• Heparin
Dialyzer/blood lines are primed with _____ solution to eliminate ___.
• Saline, air
HD is terminated by…
- Flushing dialyzer with saline to remove all blood
* Needles removed and firm pressure applied
Before HD treatment, the nurse should
Complete assessment of • fluid status • condition of access • temperature • skin condition
During HD treatment, the nurse should
- Be alert to changes in condition
* Perform vital signs every 30 to 60 minutes
What are the main complications for HD?
- Hypotension
- Muscle cramps
- Loss of blood
- Hepatitis
How does hypotension occur during HD?
• From rapid removal of vascular volume (hypovolemia), decreased cardiac output, and decreased systemic intravascular resistance
What are some factors that contribute to the development of muscle cramps during HD?
- hypotension,
- hypovolemia,
- high ultrafiltration rate (large interdialytic weight gain), and
- use of low-sodium dialysis solution
How can blood loss occur during HD?
- From blood not being completely rinsed from the dialyzer
- Accidental separation of blood tubing
- Dialysis membrane rupture
- Bleeding after the removal of needles at the end of dialysis
True or False
At one time, hepatitis B had an unusually high prevalence in dialysis patients, but the incidence today is quite low.
• True
Why does individual adaptation to maintenance HD vary considerably?
• Initially, many patients feel positive about the dialysis because it makes them feel better and keeps them alive, but often great ambivalence is expressed about whether it is worthwhile.
What are the advantages of peritoneal dialysis over hemodialysis?
- Immediate initiation
- Less complicated
- Portable system
- Fewer dietary restrictions
- Usable in patients with vascular access problems
- Less cardiovascular stress
- Home dialysis possible
What are the advantages of hemodialysis over peritoneal dialysis?
- Rapid fluid removal
- Rapid removal of urea and creatinine
- Effective K+ removal
- Less protein loss
- Lowers serum triglycerides
- Home dialysis is possible as temporary access can be provided at home
